Nickel Hydride, Alkyl and Aryl Complexes

37.4 Nickel Hydride, Alkyl and Aryl Complexes P. W. JOLLY Max-Planck-lnstitut fur Kohlenforschung, Mulheima.d. Ruhr

37.4.1 INTRODUCTION 37.4.2 NICKEL HYDRIDE COMPLEXES 37.4.2.1 Complexes Stabilized by Group V Donor Ligands 37.4.2.2 r}3-AllyI- and t)-Cyclopentadienyl-nickel Hydrides 37.4.2.3 Nickel Carbonyl Hydrides

37 37 38 41 42

37.4.3 NICKEL ALKYL, ARYL AND RELATED COMPLEXES 37.4.3.1 Ligand-free Complexes and Complexes Stabilized by ir-Bonded Ligands 37.4.3.2 Mono-ligand Nickel Alkyl and Aryl Complexes 37.4.3.3 [NiR2Ln] and [NiX(R)Ln] Complexes (n = 2-4) 37.4.3.3.1 Preparation and structure 37.4.3.3.2 Reactions 37.4.3.3.3 Physical properties and bonding 37.4.3.4 r]3-Allylnickel Alkyl and Aryl Complexes 37.4.3.5 K]-Cyclopentadienylnickel Alkyl and Aryl Complexes

44 44 49 52 63 72 80 81 85

REFERENCES

93

37.4.1 INTRODUCTION In order to avoid unnecessary duplication of the literature and because they are chemically interrelated, we have chosen to discuss the nickel hydride and the nickel alkyl and aryl complexes in one Chapter. Interest in these classes of complex has grown remarkably in the last few years and whereas up until ca. 12 years ago concrete examples of nickel hydrides were limited to the carbonyl hydrides (and even these are now being reformulated), by working at low temperature and selecting suitable reagents a whole range of complexes is now known and includes examples in which the hydrogen atom is directly bonded to the metal, bridges two or more metal atoms or occupies interstitial positions in a nickel cluster. The nickel alkyl and aryl chemistry has also expanded and, in addition to the more mundane complexes, examples have been characterized which contain alkyl groups bridging two nickel atoms, while there has been a revival of interest in the 'ate' complexes. The subject matter has been divided according to the nature of the additional ligands bonded to the nickel with separate Sections devoted to complexes stabilized by Group V donor ligands, carbon monoxide, the r;3-allyl and the 77-cyclopentadienyl groups, as well as to the 'ligand-free' nickel alkyls. Earlier work has been tabulated and discussed in detail in ref. 1.

37.4.2 NICKEL HYDRIDE COMPLEXES The known nickel hydride complexes are listed in Table 1 (p. 43) and ref. 1, pp. 152-155. 37

38

Nickel Hydride, Alky I and Aryl Complexes

37.4.2.1 Complexes Stabilized by Group V Donor Ligands Nickel hydride complexes containing one to four donor ligand molecules have been isolated. Although a systematic study has, in general, not been carried out, it is apparent that steric requirements control the number of ligands associated with the metal atom. Monophosphine nickel hydride complexes have been prepared by reacting the appropriate nickel dihalide with sodium trimethylborohydride (equation I). 1 7 5 The compounds are dark green and relatively unstable, decomposing around - 4 0 °C. Although their structure is unknown, it seems reasonable to suggest that they are dimeric with bridging halogen atoms. They react with alkenes to give nickel alkyl species. The reaction with propene has been studied in some detail and shown to be a good model for the first step in the nickel-catalyzed dimerization of propene: the hydride adds to the propene to give a mixture of «-propyl- and isopropyl-nickel species (which were not isolated) and the direction of addition was elucidated by determining the ratio of w-propyl and isopropyl chloride formed on treatment with carbon tetrachloride (equation 2). The ratio of the two halides is essentially that observed in the first step of the nickel-catalyzed reaction and moreover varies characteristically on changing the tertiary phosphine. The catalytic reaction is discussed in more detail in Chapter 56.2. [NiX2(PR3)] [NiX(H)(PR3)]

+

+

NaHBMe3

—•

f-^ MeCH=CH 2 - ( V_^

[NiX(H)(PR3)]

+

BMe3

[MeCH2CH2NiX(PR3)]

^+

^

NaX

(1)

MeCH2CH2Cl

cc.

[Me2CHNiX(PR3)]

+

Me2CHCl

(2)

The majority of the known nickel hydride complexes are stabilized by two donor ligands. The most common preparative procedure is the reaction between a bis-ligand nickel dihalide and a main group metal hydride such as NaBH4 (equation 3).117»167»176'185 The crystal structure of (1) has been investigated:189 the molecule is essentially square planar with the two phosphine molecules mutually trans. This type of reaction is, however, more complex than indicated by the equation and its course is very sensitive to the nature of the reactants and the reaction conditions and in some cases a number of not fully characterized boron-containing intermediates have been isolated. 46 " 48 ' 164 ' 188 Stable binuclear complexes, e.g. (2), have been isolated by reacting complexes similar to (1) with further sodium borohydride (equation 4). 169 A crystal structure determination shows that in (2) the nickel atom is in a distorted trigonal bipyramidal environment with the two phosphine molecules in axial positions. Complexes of this type react with nickel dihalide species to form hydrides similar to (1) (equation 5). 187

[NiCl2(PPr'3)2]

+

NaBH4

-CBH. + Nad),

C1

^NiCT?rPPri3

(3)

(1)

f [NiNO3(H)(PCy3)2]

+

NaBH4

"NaNO 2 — ^

^A i^-H^ /H H-^-Ni^ ^ B ' 2.188/ 1J3^H Cy 3

(4)

H

(2)

[NiH(PCy3)2BH4] (2)

+

[NiX2L2]

^ ^

2[NiX(H)(PCy3)L]

(5)

Nickel Hydride, Alkyl and Aryl Complexes

39

Chemical behaviour presumably related to that of the boron hydrides has been observed in the reaction of a variety of aluminium hydrides, e.g. Et 2 AlH, LiAlH 4 , with zerovalent nickel alkene complexes (equations 6, 7) 194 ' 195 ' 413 and in that of the dilithium nickel alkene complexes with hydrogen (equation 8). 192 ~ 194 The structures of these complexes are unknown, although they presumably contain bridging hydrogen atoms. Complex (3) reacts readily with triethylaluminium, in the presence of cyclooctadiene, with displacement of the lithium hydride moiety (equation 9) and with ethylene to give an anionic nickel ethyl species (equation 10).

[Ni(cdt)] 2[Ni(CH2=CH2)3]

+

+

AlHEt2

Li[AlH2Bui2]

2TMEDA

— • [NiHAlEt2(cdt)]

(6)

>

-C2H4

[(CH 2 =CH 2 ) 2 NiHNi(CH 2 =CH 2 ) 2 ]-[Li(TMEDA) 2 ] + [Ni(cod)2jLi(THF)2)2]

+

H2 ^

+

AlEtBu^

[NiH2(cod),.5Li2(THF)x]

(7) (8)

(3) (3)

+

2AlEt3

+

£cod

^ £ * [Ni(cod)2]

+

2LiAlHEt3

(9)

— cod

(3)

+

4CH 2 =CH 2

•

[NiEt(CH 2 =CH 2 ) 2 ]-[Li(THF) 4 ] +

+

LiEt

(10)

An unusual dimeric nickel dihydride complex involving the chelating phosphine PCy2(CH 2 )«PCy 2 (n = 2-4) is formed by reacting ligand nickel halide complexes with NaHBMe 3 or LiBH 4 164 ' 191 or by reacting the benzene complex (4) with hydrogen (equation II). 5 2 The X-ray structure of the resulting complex (5) 116 shows that the molecule is dimeric with bridging hydrogen atoms and a Ni—Ni bond. The structure has been described as a distorted square planar dimer in which the two PNiP planes are twisted away from each other as the result of intramolecular repulsion between the cyclohexyl groups of the two P 2 Ni units. The dihedral angle between the two PNiP planes is 63.3° and it is bisected by the Ni 2 H 2 plane. Compound (5) is surprisingly stable and does not decompose in solution until 165 °C. Reaction with alkenes, phosphines and CO lead to the displacement of hydrogen. Tris- and tetrakis-(triethylphosphine)nickel are also able to cleave molecular hydrogen to give (as yet) unidentified nickel hydride species.154'165 c

Cy2

2<^/W_C6H6)

H2

W

+ H2 ^ ^

y2

H

Cy2

A ^ ^ ^ j ^ A

x^V

(n)

(5)

Other reactions in which ligand nickel hydride complexes are generated include /3-hydrogen transfer from nickel alkyls and oxidative addition to zerovalent nickel systems. The product of the oxidative addition of acids to zerovalent nickel phosphine complexes depends upon the strength of the acid: strong acids produce cationic nickel hydrides [NiHL 4 ] + (see below) whereas weak acids react to give four (equation 12,13) 76 ' 176J90 ' 423 or five (equation 14) 1.23,130,383 coordinate species. The hydridonickel acetate complex shown in equation (12) is the starting point for the synthesis of a number of hydridonickel alkyl and aryl species, e.g. (6). 176 The reaction with HCN (equation 14) has been studied for 16 tertiary phosphines and phosphites and NMR data indicate that the molecule adopts a trigonal bipyramid with the three ligand molecules in the equatorial positions, while complexes containing bulky ligands dissociate in solution to give [NiCN(H)L 2 ] species. Complexes containing chelating ligands react similarly: the reported (see ref. 1, p. 150) formation of [Ni 2 (CN) 2 (PPh 2 C 4 H 8 PPh 2 )3] from the reaction of the bis-chelating phosphine nickel complex with HCN has been corrected; the product is in fact the nickel hydride

40

Nickel Hydride, Alky I and Aryl Complexes

(7) (equation 15). 130 For completeness we should mention here the reaction between tris(ethylene)nickel and HC1 which it is reported170 yields a red, unstable (dec. < - 7 8 °C) complex having the composition [(CH2=CH 2 )2NiHCl]. The absence of a Ni—H stretching frequency in the IR spectrum of this complex suggests, however, that it is not a nickel hydride. What might be a related complex is also formed by nickelocene with HC1. 408

[Ni(PCy3)2]

+

- ^

MeCO2H

—*-

[NiOCOMe(H)(PCy3)2]

[NiH(Ph)(PCy3)2]

+

LiOCOMe

(12)

(6) [Ni(PPh3)4]

+

HC=CPh

[NiL4] Ph2 P (CH 2 ) 4 Ph2

+

—•

HCN

[NiH(C=CPh)(PPh3)2] —^

[NiCN(H)L3]

Ph2 P Ni

+

+

2PPh3

L

(13) (14)

P H

(CH 2 ) 4

+

HCN

—+

(CH2)4

Ni-PPh 2 C 4 H 8 PPh 2

(15)

Ph2 (7)

Stable nickel hydride complexes may also be formed by ^-elimination of ethylene from a nickel ethyl or nickel alkoxide species (equations 16, 17). 149,171,172,411 ^ n analogous reaction to that shown in equation (16) involving the sterically less demanding ligand PPh3 leads to [NiBr(H)(PPh3)3]. The possibility that this species is, however, ionic does not seem to have been ruled out and addition of acetonitrile in the presence of TIBF4 causes precipitation of [NiH(PPh3)3(MeCN)] + BF 4 -. 4 0 9 ' 4 1 9

[Ni(acac)(Et)PCy3]

+

AlXEt2

+

PCy3

-(£*"«+ C»H«>,

[NiX(H)(PCy3)2]

(16)

+

(17)

-LiCl

[NiCl2(PCy3)2]

+

LiOPr1 — *

[NiCl(H)(PCy3)2]

Me2CO

It is convenient to mention here that the complex isolated from the reaction of nickel acetylacetonate with tris(isobutyl)aluminium in the presence of nitrogen and triethylphosphine and originally formulated as [NiH(PEt 3 ) 2 (N 2 )| (see ref. 1, p. 143) is almost certainly [Ni(PEt 3 ) 3 (N 2 )] with traces of an unidentified nickel hydride. 165 ' 184 Tetrakis-ligand nickel complexes are protonated by strong acids to give cationic nickel hydrides (equation 18). Exceptions are apparently reactions involving nickel tetracarbonyl 181 and [Ni(PPh 2 H)4], 182 which react to give nickel(II) salts. (The reaction with weaker acids such as HCN which proceed by oxidative addition has been discussed above). The kinetics of the formation and decomposition of [NiHjP(OEt)3}4] + have been investigated;183 the activation parameters for the formation of the chlorate in methanol are A//* = 13 ± 1 kJ mol" 1 and AS* = —2 ± 3 J K" 1 mol" 1 . NMR line shape analysis has been used to investigate the equilibrium shown in equation (19) (M = Ni, Pd, Pt). The reaction proceeds by "ligand attack along the pseudo-C4 axis of the planar HML3+ species, leaving the ligand trans to the hydride unique, with the attacking ligand ending in a position symmetry equivalent with the positions of the two trans phosphorus ligands" (equation 20). The equilibrium shown in equation (19) lies predominantly to the right for nickel and predominantly to the left for palladium and platinum. 61 ' 132146 The complexes formed

Nickel Hydride, Alky I and Aryl Complexes

41

by bidentate phosphines are considerably more stable than those formed by monodentate ligands. The tetradentate ligands P(C 2 H 4 PPh 2 ) 3 and N(C 2 H 4 PPh 2 )3 also react with nickel salts and sodium borohydride to give [NiHL 4 ] + complexes.85'99 In the case of tris(2-diphenylphosphinoethyl)amine the hydride content depends upon the method of preparation; values of 0.04 to 0.83 are obtained and are paralleled by a variation in the magnetic moment from 0.88 to 2.08 BM. The crystal structure of the complex corresponding to [NiH 0 .5(PPh 2 C 2 H 4 )3N]+BF 4 - (8) has been determined. The nickel atom lies at the centre of a regular trigonal bipyramid, the nitrogen atom occupying one apex and the hydrogen the other. Compound (8) reacts with nitric oxide to give the black-violet nitrosyl complex [NiNO(PPh2C2H4)3N]+. An X-ray diffraction study shows that here the three phosphorus atoms and the nitrosyl group are arranged in a tetrahedral manner around the nickel atom. The ligand nitrogen atom is not bonded to the nickel. The Ni—N—O angle is 168(2)°. 159

[NiL4]

+

[MH(PEt 3 ) 3 ] +

HX +

L,—M—L3

[NiHL 4 ] + X-

—^ PEt 3

^

L4

^^

+

(18)

[MH(PEt 3 ) 4 ] +

(19)

U—M'

(20)

\ _ji-—-v1'————^ /

A r~ph

ph^ - P - "

I6

i

Ph

2.20

— 6 IJM

Ph

(8)

37.4.2.2 T73-Allyl- and ^-Cyclopentadienyl-nickel Hydrides The r/3-allylnickel hydride complexes may be prepared by reacting an r;3-allylnickel halide derivative with NaBHMe3 (equation 21). ! ' 175 These complexes are of low thermal stability: (9) decomposes at - 3 0 °C while the ligand-free complex could not be isolated, disproportionation to bis(?73-allyl)nickel occurring even at —140 °C. The analogous PF3 complex has been shown by NMR spectroscopy to rearrange reversibly to give a propene-nickel species formulated as (10) (equation 22). Reaction of the corresponding deuteride leads to exclusive deuteration of the terminal C atoms of the propene molecule, an observation which is of some interest since it indicates the plausibility of a nickel-catalyzed 1,3-hydrogen shift mechanism for alkene isomerization as an alternative to the more common /3-hydrogen elimination-addition process. [NiBr(PPh3)(773-C3H5)]

+

NaHBMe 3

[NiH(PPh3)(i?3-C3H5)]

—*

+

BMe3

+

NaBr

(9) (21) /—Ni/ Y

N

^

I)—Ni—PF3

PF3 (10)

(22)

42

Nickel Hydride, Alkyl and Aryl Complexes

T7-Cyclopentadienylnickel hydride complexes are still rare. Bis(tricyclohexylphosphine)nickel reacts with cyclopentadiene to give the nickel hydride (11), presumably through the intermediacy of a nickel-774-cyclopentadiene species (equation 23). 176 A related complex (12) containing a 7r-bonded carborane molecule has been isolated from the thermal rearrangement of [Ni(PPli3)2(C2B9Hi i)] during which a boron-bonded hydrogen atom and a triphenylphosphine molecule exchange positions (equation 24). 148 H

[Ni(PCy3)2] +

O V

—*" r
—'

L ^

J



+ PCy3 (23)

>Cy3 (11)

Phl

[Ni(PPh3)2(C2B9H11)]

—

\<"

|\/^By\/B"PPh3

(24)

A /\ A

W (12)

An unusual cluster compound, [ ( N i ^ - C s H s ^ H s ] , is formed if [NiNO(r/-C 5 H 5 )] is reacted with LiAlH 4 . 45 ' 62 - 173 ' 174 The nickel atoms occupy the corners of a tetrahedron and each is 7r-bonded to a planar cyclopentadienyl ring. A neutron diffraction study has shown that the three hydrogen atoms face-bridge three of the four tetrahedral faces. This molecule is discussed further in Chapter 37.8.

37.4.2.3 Nickel Carbonyl Hydrides Protonation of the anionic nickel carbonyl species discussed in Section 37.2.6 (p. 10) leads to the formation of the nickel carbonyl hydrides. Earlier reports concerning their composition and structure (see ref. 1, p. 148) must be viewed with caution since these will undoubtedly have to be revised to accommodate the reformulation of the anions from which they are derived. The structures of three nickel carbonyl hydrides have been recently elucidated and these are discussed below. Reaction of [Ni 5 (CO)i 2 ] 2 ~ with CO and water leads to the elimination of nickel tetracarbonyl and formation of [Ni 2 (CO)6H]~ (13). This same complex is more conveniently prepared by reacting the interstitial dihydride discussed below with CO at ambient temperature and pressure (equation 25). 177 ' 270 A crystal structure of (13) shows the presence of two eclipsed Ni(CO)3 fragments with the hydrogen atom probably randomly distributed between two symmetry-related bridging sites and ca. 1.7 A away from the nickel.

'A [Ni12(CO)21H2]-

+

23CO

^

^

H

/

2 '"^i^NiCav.)

(25)

c\

A (13)

Hydrolysis of [Ni6(CO)i 2 ] 2 ~ results in the formation of two hydride species, viz. [Ni,2(CO) 2 1 H 2 ] 2 - (14, at pH ca. 4) and [ N i , 2 ( C O ) 2 , H p - (15, at pH ca. 5-8). The IR spectra

Nickel Hydride, Alkyl and Aryl Complexes

Table 1

Nickel Hydride Complexes3

Complex

Ref.

[NiX(H)LnJ Complexes [NiCl(H)(PEt 3 ) 2 ] a 76 i a NiCl(H)(PPr 3)2] (D 167, 189 NiNCS(H)(PPr i 3 ) 2 ] 117 NiNCOCHXPPr^] 117 NiNO 2 (H)(PPr i 3 ) 2 ] 117 j NiCN(H)(PPr 3 ) 2 ] 117 a NiCl(H)(PCy 3 ) 2 ] 76, 126, 167, 171, 411 NiBr(H)(PCy 3 ) 2 ] a 171,411 NiNO 3 (H)(PCy 3 ) 2 ] 117 NiNCO(H)(PCy 3 ) 2 ] 117 NiNO 2 (H)(PCy 3 ) 2 ] 117 NiBr(H)(PPh 3 ) 3 ] 149,172,419 NiH{2,6-(CH2PBu2)2C6H3}] 147 NiCN(H)(PR 3 ) 3 ] 23, 130 NiBH4(PPh3)3] 46-48 NiBH 3 CN(PPh 3 ) 2 ] 46,47 NiH(BH 3 CN)(PPh 3 ) 2 ] 46,47 NiGe(C 6 F 5 ) 3 (H)(PPh 3 ) 2 ] 423

NiH(BH3CN) ( [ C ^ JLC_^J] . Va Ph A J

46,47

NiH(BH 4 )(PCy 3 ) 2 ] (2) 168, 169 {NiH(PCy2C2H4PCy2)}2]a 52, 164 :{NiH(PCy2C3H6PCy2)}2]a (5) 52, 116, 164 NiCN(H)(PPh 2 C 4 H 8 PPh 2 ) 2 ] (7) 130 NiH 2 (cod),. 5 Li 2 (THF) x ] (3) 192 + [NiHL4J Complexes NiH[P(OMe)(OCH) 2 CMe 2 j 4 ] + 94 NiH{P(OCH 2 ) 3 CC 6 H l3 } 4 ] + 94 NiH{P(OCH 2 ) 3 CMe| 4 ] + 94 NiH{P(OEt) 3 } 4 ] +a 23,410 NiH{P(OEt)2Ph}4]+ 23 NiH(PPh 3 ) 3 (MeCN)]+ 409 NiH(PPh 2 C 2 H 4 ) 3 P]+ 85 NiH(PPh 2 C 2 H 4 ) 3 N] + (8) 99, 159 NiH(PPh 2 C 2 H 4 PPh 2 ) 2 ]+ 23, 44, 59, 188 NiH(PPh 2 C 2 H 4 SEt) 2 ]+ 383 NiH(PMe2Ph)4]+ 154 NiH(PMe 3 ) 4 ] + 154 NiH(PEt 3 ) 4 ] + 61,132,146,154 + NiH(PCy 3 ) 2 (py)] 100,117 + NiH(PCy 3 ) 2 (2-Mepy)] 100,117 NiH(PCy3)2(3-Mepy)]+ 100,117 NiH(PCy 3 ) 2 (4-Mepy)] + 100, 117, 126 NiH(PCy3)2(4-Phpy)]+ 100, 117 + NiH(PCy 3 ) 2 (pyraz)] 100, 117 NiH(PCy 3 ) 2 (imidaz)] + 100, 117 + NiH(PCy 3 ) 2 (MeCN)] 126 Ni(r]-C5Hs) Hydride Complexes [{Ni(77-C5H5)}4H3] 45,62,174 [NiH(C 2 B 8 H, 0 PPh 3 )(PPh 3 )] (12) 148 Nickel Carbonyl Hydrides

[HNi2(CO)6]-(13) [H2Nii2(CO)2,]2-(14) [HNii2(CO)2,]3-(15) a

177,270 177,178 177,178

Earlier work is discussed and tabulated in ref. 1, pp. 139-155.

43

44

Nickel Hydride, Alkyl and Aryl Complexes

indicate that both contain terminal and bridging carbonyl groups, while the high shielding of the hydrogen atom (5 H , (14) = 28; 5 H , (15) = 36 p.p.m.) suggests that they are interstitial in nature, i.e. occupy holes in the nickel lattice. 177179 This is borne out by X-ray and neutron diffraction studies: 178 in both molecules [Ni6(CO)9] fragments are capped symmetrically by two identical [Ni3(CO)6] fragments. The hydrogen atoms in the dihydro dianion (14) are located exclusively at the octahedral sites, lying closer to the central Ni$ plane (av. Ni—H = 1.84 A) than the outer Ni3 planes (av. Ni—H = 2.01 A). The single interstitial hydrogen atom in the monohydro trianion (15) is also located at an octahedral site but is so much closer to the central Ni6 plane that it may be considered as triply bridging the central three metal atoms (av. Ni—H = 1.72 A).

Q

(15)

A neutral cluster complex, [H2NiOs3(CO)io(PPh 3 ) 2 ], has been prepared by reacting [H 2 Os 3 (CO)io] with [Ni(PPh 3 ) 2 (CH 2 =CH 2 )]. Its structure is not known but spectroscopic results indicate that the molecule contains both terminal and bridging carbonyl groups and that one triphenylphosphine molecule is bonded to nickel and the second to osmium.180

37.4.3 NICKEL ALKYL, ARYL AND RELATED COMPLEXES 37.4.3.1 Ligand-free Complexes and Complexes Stabilized by 7r-Bonded Ligands This Section is devoted to complexes of the type [NiR2] or [NiX(R)], to the ionic 'ate' complexes and the complexes formed by ylides. Recent examples are listed in Table 2 (p. 50); earlier work is discussed in ref. 1, pp. 159-163. A number of complexes have been isolated having the composition [NiR2] or [NiX(R)] in which the nickel atom formally has only 12 electrons in its valence shell. However, in no case has the identity of a solvent-free species been demonstrated unequivocably. The most likely candidate is bis(mesityl)nickel which may be formed by reacting r?3-allylnickel bromide with mesitylmagnesium bromide (equation 26) or by vacuum removal of the phosphine molecules from [Ni(mesityl) 2 (PEt 3 ) 2 ] (see ref. l,p. 159). Bis(trityl)nickel, formed by reacting bis(cyclooctadiene)nickel with hexaphenylethane, could be an ?73-allyl complex.1'353 [{NiBr(773-C3H5)!2]

"2MgBF2>

+

4 mesityl MgBr

2HO)-NiHO)~

+

2C3H5MgBr

(26)

Cocondensation of nickel vapour with pentafluorophenyl bromide produces [NiBr(C6Fs)] (16), which decomposes above - 8 0 °C (giving decafluorobiphenyl) but which can be trapped by adding

Nickel Hydride, Alky I and Aryl Complexes

45

a tertiary phosphine (equation 27). 13,57,297,412 ^ complex having the same composition has been isolated as a stable yellow solid from the electrolysis of C6F5Br with a nickel anode;3" this material also forms the expected adduct with triethylphosphine. In the presence of toluene, (16) disproportionates to give the toluene adduct to bis(pentafluorophenyl)nickel (17) (equation 28). The Ni—C bonds in (17) and the analogous mesityl adduct have the relatively short lengths of 1.891 A 297 and 1.898 A,186 respectively. The toluene molecule can be exchanged, in a first-order reaction, with other arene ligands. Bis(pentafluorophenyl) nickel produced by the Grignard method has been shown to be associated with two solvent (e.g. dioxane) molecules.16283 The reaction of the Ni-THF slurry (formed by cocondensation of nickel vapour with THF) with organic halides suggest that here also [NiX(R)] species are generated which then decompose by homolytic cleavage of the Ni—C bond,364 while [Ni(C6F5)2] has been isolated from the reaction of the slurry, produced by lithium-naphthalene reduction of a nickel halide with iodopentafluorobenzene in THF or 1,2-dimethoxyethane.412 In addition, the reactions between NiX 2 and organomain group metal reagents have been studied; organonickel species have not been isolated and the value of conclusions concerning the course of reaction based upon analysis of the decomposition products is rather limited 50 ' 95 ' 103105 ' 108 ' 280 ' 361 (see also ref. 1, p. 157).

Ni

+

C6F5Br

—^

[NiBr(C6F5)]

i ^

[NiBr(C6F5XPEt3)2]

(27)

(16) ^ \

2[NiBr(C6F5)]

+

~NiBr2>

C6H5Me

1.891/^5

lOr"Ni

Me^^

877

( 28 )

°

V6F5

(17) A generalized valence bond treatment of Ni—Me and Ni—CH2 350 and ab initio MO-SCF calculations for [NiMe2] and [NiMe 2 (CH 2 =CH 2 )] 91 ' 280 ' 340 ' 341 ' 360 have been published. In all cases the d-orbitals on nickel are found to play essentially no role in the bonding. The Ni—C bond has considerable ionic character with a net charge of —0.4 to —0.5 on the methyl group and is suggested to be relatively strong (ca. 250-270 kJ mol" 1 ). The optimal bonding situation for Ni—Me is observed with a Ni—C separation of 1.87 A while that for [NiMe2] corresponds to a linear arrangement with a Ni—C bond length of 2.003 A. The addition of a carbanion (R~) to the [NiR2] complexes discussed above generates 'ate' complexes (e.g. [NiR4]2~), familiar from organomain group metal chemistry. Examples of this class of compound in nickel chemistry were limited for many years to the tetraalkynylnickelates (equation 29, see ref. 1, p. 161). Recently, however, a number of tetraalkyl and tetraaryl complexes have been isolated (equations 30-32) and the importance of a proper choice of nickel(II) chelate complex as starting material has been stressed.107 Most of these complexes are associated with solvent molecules, which in the case of ammonia can frequently be removed by subjecting the complex to a vacuum. In one case,362 reduction of a nickelate to a zerovalent nickel species has been reported (equation 33). A formal relationship exists between these reactions and that of [Ni(C6F5)2(dioxane)] with halide or cyanide, from which dimeric ionic species have been isolated (equation 34). 284 [Ni(CN)4]K2

+

4KC=CR

-+

[Ni(C=CR)4]K2

+

4KCN

(29)

N=(, }=N N i

(

<

O

N

[NiCl4][NBu4]2

\ ^ )

+

4LiC 6 F 5

+

4 U M e

—+

^ T

[NiMe4][LiTHF]2

[Ni(C6F5)4][NBu4]2

+

4 LiCl

(30)

(31)

46

Nickel Hydride, Alkyl and Aryl Complexes -THF

[NiPh4][Li(THF)2]2

+

LiPh

[Ni(O=CPh)4]K2 [Ni(C6F5)2(dioxane)2]

• [NiPh3][Li(THF)]3

+ +

2K

—•

2 KCN

—-

+

PhPh

[Ni(C=CPh)4]K4 [{Ni(C6F5)2CN|2]K2

(32) (33) (34)

In contrast to the main group metal 'ate' complexes, those of the transition metals can form stable adducts with donor ligands or unsaturated organic molecules. (For a recent review of this area, see ref. 413.) Complexes of this type have been prepared by addition of a carbanion to a zerovalent nickel alkene complex (equation 35), 194 by exchange of 7r-bonded ligands (equations 36, 37),49,i4i,i94 o r ^ substitution of a x-bonded ligand by a carbanion (equations 38, 39) 140,143,193,194,357 j n e e t n y i a n a logue to (20) has also been prepared by reacting the dilithium adduct of tris(ethylene)nickel with hydrogen or the dihydride [NiH2(cod)i.5Li2] with ethylene 192,193 A complex related to (18), viz. [NiPh 2 (cod)]Li 2 (THF) x , has been isolated from the reaction between bis(cyclooctadiene)nickel and LiPbPh 3 , phenyl transfer from lead to nickel having occurred. 356 This reaction is, however, not a general one and reaction of [Ni(cod) 2 ] or [Ni(PPh 3 )2(CH2=CH 2 )] with [MPh 3 ]" (M = Si, Ge, Sn) leads instead to ligand substitution products, e.g. [Ni(SiPh 3 )3]Li 3 (THF)5 and [Ni(SnPh 3 ) 3 (PPh 3 )]Na 3 (THF) 5 . 342 ' 356 ' 363 [Ni(cdt)] + [NiPh2(cdt)]Li2

+

LiPh

-^^

CH 2 =CH 2

[NiPh(cdt)]Li(THF)4

- ^

[NiPh2(CH2=CH2)]Lirether

(35) (36)

(18) [NiPh2(cdt)]Li2

+

N2

LlPh/ether

>

[|Ni2Ph4(N2)Li4(ether)2(LiPh)2j2]

(37)

(19) [Ni(PPh3)2(CH2=CH2)] [Ni(cod)2]

+

LiMe

+

+

2 LiPh

2CH 2 =CH 2

- ^

+

[NiPh2(PPh3)2][Li2(ether)3]

2NMe2C2H4NMe2

(38)

~2cod>

1.98 H

2CV.36

(-)/A:H2L25 Me—Ni \ CH2L28 H2/L38

Li+(NMe2C2H4NMe2)2

(39)

2.00

(20)

The complexes in which the lithium atom is associated with two tetramethylethylenediamine (TMEDA) molecules are probably correctly formulated as ionic species. Thus (20) has been shown 143 to consist of discrete nickel and lithium ions ca. 5.8 A apart with the two ethylene molecules and the methyl group arranged in a trigonal plane around the nickel atom. In other cases, however, interaction occurs between the alkali metal and the nickel. The sodium analogue to (18) has been shown to be a dimer having the composition [(NiPh2(CH 2 =CH 2 )} 2 ]Na 4 (THF) 5 and structure (21), in which each nickel atom interacts with two bridging and one terminal sodium atom in addition to ethylene molecules and phenyl groups (Ni—Ph = 1.98, 1.99 A). 1 2 3 The product of the reaction between [NiPh 2 (cdt)]Li 2 (ether) x and phenanthrene, i.e. [NiPh 2 (phenanthrene)]Li 2 (THF) 4 , has structure (22) in which two a-bonded phenyl groups (Ni—Ph = 1.950, 1.963), a r/2-bonded phenanthrene molecule and two lithium atoms interact with the nickel atom.413 A partial structure of the diphenylnickel dinitrogen complex (19) is also shown. Here again the phenyl groups and the 7r-bonded ligand are arranged trigonally about the central nickel atom. The dinitrogen molecule bridges two nickel atoms which are within a bonding distance of each other. 140 A similar arrangement has been found in the complex formed

47

Nickel Hydride, Alky I and Aryl Complexes

1.92

(19)

(21)

C(24)

C(41)

C(32)

C(40)

C(3)

(22)

by reacting [Ni(cdt)] with a mixture of phenyllithium and phenylsodium as well as dinitrogen and which has been shown crystallographically to have the composition [(NiPl^h^-Ph(Na-Et2O)2NaLi6(OEt)4Et2O]2.55 Important bond distances for this species include Ni—Ph 1.97(3), Ni—N 1.911(9), N—N 1.359(18) and Ni—Ni 2.749(7) A. The complexity of these last two structures can, however, only be appreciated by consulting the original literature. A fascinating series of complexes containing four Ni—C a-bonds has been isolated from the reaction of nickel halide derivatives with ylides and double ylides. Me 3 P=CH 2 reacts with [NiCl2(PMe3)2] to give initially the ionic complex (23), which then reacts further to the dinuclear

48

Nickel Hydride, Alkyl and Aryl Complexes

species (24) and (25). 9 ' 33 ' 54 The X-ray structural analysis of (24) shows that the trimethylphosphonium bis-methylide is acting as both a chelating ligand and as a monodentate ligand. The ligands are arranged in a square planar geometry around the nickel. The proximity of the phosphorus atom in the chelating ligand to the central nickel atom (2.536 A) suggests that they interact with each other and a hetero 773-allyl arrangement has been discussed.33 Products, e.g. (26), containing analogous chelating ylide molecules have been isolated from reactions with Bu l 2 P(Me)=CH 2 and (CH 2 ) w P(Me)=CH 2 (n = 4, 5) (equation 40). 354 It is appropriate to mention here the reaction of Me3P=CH 2 with [NiKPPl^hCHfe], which leads to the formation of [NiCH 2 PMe 2 CH 2 (PPh 2 ) 2 CH] in which both a cyclic ylide and a bis(phosphino)methanide ring interact with the nickel. An X-ray structural determination of the analogous platinum complex shows the ylide ring to be folded.382

C\KM

H2 H2 1.736^^031 1^97^0^754

xCH2PMe3

d~"

Me2P

Ni

X

CH2PMe3

C

PMe2 ^

(23) H2 (24)

H

V C 'Me 2 P Me2Px H2K

Ni \

^CH2 / \-^CH 2 N

p., / Me2 CH2

(25) [NiCl2(PMe3)2]

+

(^P(Me)=CH2

^=+

,c 2

&2

V T /

'—

(CH2)4PMe2+Cl-

'

(40)

(26)

Double ylides react to form chelate complexes. Hexamethylcarbodiphosphorane undergoes a transylidation to give (27) (equation 41 ). 351 Structurally related complexes, viz. (28) and (29), are formed in reactions with H 2 B ( P M e 3 = C H 2 ) " L i + and M e 3 P = N P Me2=CH2. 344 ' 352 ' 358 Both complexes have similar crystal structures in which the six-membered chelate ring adopts a chair conformation.

NiCl2

+

4 Me 3 P=C=PMe 3

—• Me2 /P—CH2

HC

Me 2 CH2-P Ni

X

CH X

P—CH 2 Me2

CH 2 —p Me 2 (27)

+

2 Me 3 PHPMe 3 + Cl-

(41)

Nickel Hydride, Alkyl and Aryl Complexes

49 1.60, '1.59

Hz

...

, '2

37.4.3.2 Mono-ligand Nickel Alkyl and Aryl Complexes Complexes in which only one Group V donor ligand molecule is associated with the nickel atom are discussed in this Section. Earlier results have been included in ref. 1, pp. 163-168. Recent examples are listed in Table 3 (p. 53). A series of alkyl- and aryl-nickel acetylacetonate complexes containing a single phosphine molecule have been prepared by reacting nickel acetylacetonate with organoaluminium compounds in the presence of phosphine (equation 42),21'38'97'113,I62,198,201,203 o r by protonation of the dimeric trimethylphosphine(methyl)nickel hydroxy or methoxy complex with acetylacetone (equation 43). n The crystal structures of the methyl complex (30) 204 and of [Ni(acac)(Et)(PPh 3 )] 38 have been determined: the nickel atom in both is in a square planar environment with Ni—C bond distance of 1.94(1) A and 1.97(1) A, respectively.

Ni(acac)2

+

AlMe3

+

"A1Me2 (acac) ,

PCy3

93^Ni^-|J

)

(42)

2ROH

(43)

(30) [|NiOR(Me)(PMe3)|2]

+

2Hacac

— •' 2[Ni(acac)(Me)(PMe3)]

+

Insertion into the Ni—C bond has been observed on reacting this class of compound with CO (equation 44), 144,152,200 e thylene under pressure (equation 45) 205 and alkynes (equation 46). 197 [An X-ray study has confirmed the Z-vinyl arrangement in (31)]. The nature of the products of the reaction of [Ni(acac)(Ph)(PR 3 )] with alkenes, e.g. trans-VhCH=CHMe formed in the reaction with propene, indicates that here also alkene insertion has occurred although no organonickel intermediate could be isolated.198 The acyl complexes react further with elimination of CO to give ketones (equation 47), 152,200 while the Ni—C bond is readily cleaved by reaction with hydrogen, 113 ' 163 organic acids21 and organic halides (equation 48). 198 ' 200

Ni(acac)(Me)(PMe3)] [Ni(acac)(Et)(PCy3)]

+

+

CO —* [Ni(acac)(COMe)(PMe3)]

«CH 2 =CH 2

—•

[Ni(acac){(CH2=CH2)wEt|(PCy3)]

M e

[Ni(acac)(Me)(PPh3)]

+

PhC^CPh

—

(44)

\ 1 327

yph

,C=Cvsi. 897^0—/

PhX

2.178/Nl^ \ Ph3P O—(

(31)

(46)

(45)

Nickel Hydride, Alky I and Aryl Complexes

50

Table 2

Ligand-free and Ionic Nickel Alkyl and Aryl Complexes Complex

Ref.

Ligand-free Complexes NiCl(CH2Ph)] 311,364 NiBr(C6F5)l (16) 13,297,311 ;NiCl(C6F5)] 57 Ni(C6F5)2(toluene)] (17) 268,297,412 Ni(C6F5)2(mesityl)] 421 Ionic and Alkali Metal Complexes 107 [NiMe 4 ]Li 2 (THF) 2 NiMe(CH 2 =CH 2 ) 2 ]Li(TMEDA) 2 (20) 143, 193 NiEt(CH2==CH2)2]Li(TMEDA)2 143, 192, 193 NiEt 2 (CH 2 =CH 2 )]Li 2 (ether) 2 43 Ni(CH 2 NC 5 H, 0 ) 4 ] Li2(ether)2 157 Ni(CHPh 2 ) 4 ]Na 2 (?) 103 Ni(C=CH 2 CMe 2 CN) 4 ]K 2 (NH 3 ) 359 Ni(C=CCH 2 CPh 2 CN) 4 ] K 2 (NH 3 ) 359 Ni(C=CPh) 4 ]Li 2 (THF) 4 107 384 NiPh 3 ]Li 3 (THF) 3 NiPh 4 ]Li 2 (THF) 4 107 NiPh 2 (CH 2 =CH 2 )]Li 2 (ether) (18) 49,140,404,413 NiPh 2 (CH 2 =CH 2 )]Na 2 (ether) 2 140 {NiPh 2 (CH 2 =CH 2 )} 2 ]Na 4 (THF) 5 (21) 123, 140, 194 NiPh2(cod)]Li2(TMEDA)2 194,404,413 NiPh2(cod)]Li2(THF)4 194,356,384,404,413 NiPh2(bicycloheptene)]Li2(ether) 194,404,413 NiPh 2 (cdt)]Li 2 (THF) 4 194,413 NiPh2(PPh3)2]Li2(ether)3 357 {(NiPh2)2N2Ph(Na-ether)2NaLi6(OEt)4etherj2] 141,194 {(NiPh2)2N2Li4(ether)2(LiPh)2}2](19) 49,55,194 NiPh2(naphthalene)]Li2(THF)x 194,404,413 NiPh2(phenanthrene)]Li2(THF)4(22) 194,404,413 (NiPh 2 ) 2 (EtC=CEt)] Li2(THF)6 404,413 NiPh 2 (Ph 2 C=O)]Li 2 (THF) 4 413 NiPh 2 (MeCN)]Li 2 (THF) 3 404,413 NiPh(CH 2 =CH 2 ) 2 ]Li(TMEDA) 2 143, 193 NiPh(cdt)]Li(THF) 4 194,413 Ni{2,6-(OMe)2C6H3}4|Li2(THF)3 355 ;Ni(C6F5)4](NBut4)2 349 {NiCl(C6F5)2}2](NMe4)2 284 {NiBr(C6F5)2}2](PPh4)2 284 {NiCN(C6F5)2}2](NMe4)2 284 NiCN(C 6 F 5 ) 2 (PPh 3 )]NMe 4 284 Ni(C 6 Cl 5 ) 4 ](NBu t 4 ) 2 349 Ylide Complexes [Ni(CH 2 PMe 2 CH 2 ) 2 ] (24) 9,54 [Ni 2 (CH 2 PMe 2 CH 2 ) 4 ] (25) 9, 33, 54 [NiCl(CH2PMe3)2(PMe3)]Cl (23) 9,54 [Ni(CH2PBul2PCH2)2] 354 [Ni(CH 2 P(CH 2 ) 4 CH 2 ) 2 ] (26) 354 [Ni(CH 2 P(CH 2 ) 5 CH 2 ) 2 ] 354 [Ni(CH 2 PMe 2 NPMe 2 CH 2 ) 2 ] (29) 347, 352 [Ni(CH 2 PMe 2 CHPMe 2 CH 2 ) 2 ] (27) 348,351 [Ni(CH2PMe2BH2PMe2CH2)2] (28) 344, 358 [NiCH(PPh 2 ) 2 (CH 2 PMe 2 CH 2 )] 382 a

Earlier work is discussed and tabulated in ref. 1, pp. 159-163.

2[Ni(acac)(COEt)(PPh3)]

—•

[Ni(acac)(COPh) (PPh3)J

[Ni(CO)2(PPh3)2] +

Mel

—>

+

Ni(acac)2

PhCOMe

+

+

Et2CO

[LNi(acac)I]

(47) (48)

An alkylnickel acetylacetonato complex related to those discussed above, viz. (32), has been prepared by reacting bis(cyclooctadiene)nickel with acetylacetone (equation 49).206 An X-ray structural determination has confirmed the square planar arrangement of the ligands.207 Other

Nickel Hydride, Alky I and Aryl Complexes

51

examples of this type of complex have been prepared by metathetical substitution (equations 50-52; see ref. 1, p. 165). Under certain conditions the r/'^^-CgHn fragment isomerizes to the r;3-cyclooctenyl form and this is discussed further in the Chapter devoted to the 773-allyl complexes (p. 145). A further example of an alkene-stabilized nickel alkyl species is generated as the result of insertion of norbornene into a nickel-bonded 2-methylallyl group (equation 53).86 The reaction may be reversed by treatment with HC1. The crystal structure of (33) (and the analogous trifluoroacetato complex) has been determined:20'69'70'114 two slightly different forms exist in both of which the nickel is in an approximately square planar environment.

[Ni(cod)2]

+

Hacac

^

f ) \ / ° ^ ~ \ N / y1N 2 \i .93 / \jjl.42

(49)

2.03

(32) [NKacacX^-QHn)] [NiCK^-CsHn)]

+

+

HC1 —* [NiCK^'^-CgHn)]

NaOMe

[Ni(acac)(V'2'5-C8H13)]

+

LiMe

+

—*- itJNiOMefr^-CgHn)}^ y[fNiMe(^'2'5-c8H13)J2]

-+

+

Hacac

(50)

+

NaCl

(51)

Liacac

(52)

I—cjr^ /^2oo

2

1-89/ 2.00Ov

Cl

N

^" vK ^^

Vr

(53)

CO (33)

In a number of cases involving trimethylphosphine, reactions which might have been anticipated to produce [NiX(R)L2] complexes, give instead dimeric [{NiX(R)(L)J2] systems in which the anion bridges the nickel atoms (equation 54). 11,12,145,385 p u r ther examples have been prepared by metathetical exchange or by protonolysis (equations 55, 56).53 The structure of these complexes

2[NiMe2(PMe3)3]

+ zHX

~2L/2C"4> - ^

[{NiOMe(Me)(PMe3)|2]

+

2[NiX(Me)(PMe3)2] [{NiX(Me)(PMe3)!2]

2 NaNHR —•

[|NiNHR(Me)(PMe3)j2]

[jNiOMe(MeKPMe3)|2] —•

+

[|NiOPMe2O(Me)(PMe3)j2]

(54) +

2 NaOMe (55)

2 Me2P(O)OH +

2 MeOH

(56)

52

Nickel Hydride, Alkyl and Aryl Complexes

has been studied with the aid of NMR and is dependent upon the nature of X: in some cases (e.g. X = OPh) a mixture of cis and trans isomers is observed (34, 35), whereas in others, only one form is present (e.g. X = OMe, cis; X = F, trans). In addition to the complexes shown in Table 3, a variety of mixed complexes, e.g. [LNi(Me)Cl-NMe 2 Ni(Me)L], have been prepared. Complexes which may well be related have been obtained by reacting methylmagnesium bromide with an T;3-allyl nickel complex (equation 57; see ref. 1, p. 163), by reacting the [NiX(H)L] complexes with alkenes (see p. 38) or by reacting bis(mesityl)nickel with triethylphosphine (equation 58). 208

x x

Me.

>X.

/PMe3

Me3P

X

Me

x x

Me.

+

[Ni(mesityl)2]

.Me

Xx

Me3P

(34, trans) [NiMe(PCy3)U3-C3H5)]

.X.

PMe3

(35, cis)

MeMgBr

—^

[NiMe2(PCy3)]

+

—•

[Ni(mesityl)2(PEt3)]

PEt3

+

C3H5MgBr

(57) (58)

The oxidative addition of chloro- or bromo-pyridine to tetrakis(triphenylphosphine)nickel (equation 59) produces the dimeric monophosphine nickel complex (36). It is suggested that this complex contains bridging halide atoms, although structures involving bridging pyridine groups do not appear to have been excluded.295'386 An unusual, electron deficient, monophosphine complex has been prepared by the oxidative addition of methacrylamide to bis(cyclooctadiene)nickel in the presence of phosphine (equation 60). 276 The resulting nickelacyclic amide reacts with CO to give a quantitative yield of 3-methylsuccinimide.

a IN

Ph3Px

CL

Cl

(Q^

Cl^

J O

>ON

—* ^ O <

x

(59)

PPh 3

(36) \ [Ni(cod)2]

+

/NH2

N^O

y~^

+

PCy3

^ ^

Cy3PN(Jj^

(60)

A dimeric monophosphine complex is also formed in the reaction of [NiCl(Me)(PMe3)2] with the ylide trimethylenephosphorane: an ionic species is formed initially and reacts further to give (37), in which the nickel atoms are bridged by dimethylphosphonium bis-methylide groups (equation 61). 53 2[NiCl(Me)(PMe3)2]

+

4 Me3PCH2

z

^ Me2

Me

CH2

CH 2

Ni Me 3 P^

PMe3 Ni

CH 2

CH2

+

2Me4PCl

(61)

Me

Me2 (37) 37.4.3.3 [NiR 2 L n ] and [NiX(R)Ln] Complexes (n = 2-4) The majority of the known nickel alkyl and aryl complexes are stabilized by two donor ligands. In addition, examples have been isolated, many of them ionic, which contain three or four ligand molecules. Complexes which have been recently isolated or investigated are listed in Tables 4-7 (pp. 54-63). Earlier work is tabulated and discussed in ref. 1, pp. 168-208.

Nickel Hydride, Alkyl and Aryl Complexes

Table 3

Monoligand Nickel Alkyl and Aryl Complexes3

Complex [Ni(acac)(Me)(PPh3)] Ni(acac)(Me)(PPh2Et)] Ni(acac)(Me)(PCy3)]a (30) Ni(acac)(Me)(PMe3)] Ni(acac)(Et)(PPh3)] Ni(acac)(Et)(PPh2Me)] ;Ni(acac)(Et)(PCy3)]a Ni(acac)(Bui)(PCy3)]a Ni(acac)(Bz)(PPh3)] Ni(acac)(Bz)(PBz3)] Ni(acac)(Bz)(PCy3)] Ni(acac){CPh==C(Me)Ph}(PPh3)](31) Ni(acac)(Ph)(PPh3)] Ni(acac)(Ph)(PCy3)] Ni(acac)(Ph)(PEt3)] Ni(acac)(COPh)(PPh3)l Ni(acac)(COPh)(PCy3)] Ni(acac)(COPh)(PEt3)] Ni(acac)(COEt)(PPh3)] Ni(acac)(COMe)(PPh3)] Ni(acac)(COMe)(PMe3)] {Ni(OH)(Me)(PMe3)}2] jNi(OMe)(Me)(PMe3)}2] jNi(OEt)(Me)(PMe3)}2] JNi(OSiMe3)(Me)(PMe3)}2] jNi(OPh)(Me)(PMe3)}2] {Ni(O-p-Tol)(Me)(PMe3)}2] {Ni(O2CH)(Me)(PMe3)}2] ;{Ni(O2CMe)(Me)(PMe3)}2] ;{NiCl(Me)(PMe3)}2] {NiF(Me)(PMe3)}2] {NiNH 2 (Me)(PMe 3 )} 2 ] {Ni(NH-/7-Tol)(Me)(PMe3)}2] {Ni(OPMe 2 O)(Me)(PMe 3 )| 2 ] [{Ni(CH 2 PMe 2 CH 2 )(Me)(PMe 3 )} 2 ](37) [NiNHCOCH(Me)CH 2 (PCy 3 )] {NiCl(2-NC5H4)(PPh3)}2] (36) {NiBr(2-NC5H4)(PPh3)}2] {NiI(2-NC5H4)(PPh3)}2] {NiCl(6-Cl-2-NC5H3)(PPh3)}2] {NiCl(5-Cl-2-NC5H3)(PPh3)}2] |NiCl(3-NC5H4)(PPh3)}2] {NiCl(2-N2C4H3)(PPh3)}2] {NiCl(6-OMe-2-NC5H3)(PPh3)}2] {NiCl(8-NC9H6)(PPh3)}2] |NiN3(6-OMe-2-NC5H3)(PPh3)}2] {Ni(NCO)(6-OMe-2-NC5H3)(PPh3)}2] JNi(NCS)(6-OMe-2-NC5H3)(PPh3)}2] {Ni(NCSe)(6-OMe-2-NC5H3)(PPh3)}2] {NiN3(6-Cl-2-NC5H3)(PPh3)}2] {Ni(NCO)(6-Cl-2-NC5H3)(PPh3)|2] {Ni(NCS)(6-Cl-2-NC5H3)(PPh3)}2] {Ni(acac)(6-Cl-2-NC5H3)(PPh3)}2] NiCl(C6Cl5)(PPh3)] Ni(acac)(r7''2'5-C8Hi3)]a (32) [NiOCMeCC(CF 3 )0(y> 2 ' 5 -C 8 H 13 )] [NiOC(CF 3 )CC(CF 3 )0( V-2'5-C8H,3)] [{Ni(OCOMe)(r/'^-C11H17)}2](33) [{Ni(OCOCF3)(r;>^-CnH17)}2] a

Ref. 197 113 203, 204 11 21,38,97, 113, 162,163 113 97, 203 90S

203 201 201 201 197 198 198 198 200 200 200 152 152 144 11 11 11 11 11 11 11 11 11 12 12, 145 12 53 53 276 295, 386 295, 386 295, 386 295, 386 386 295, 386 386 386 386 386 386 295, 386 386 386 386 386 386 392, 393 199 199 199 20, 69, 70, 86 86, 114

Earlier work is discussed and tabulated in ref. 1, pp. 163-168.

53

54

Nickel Hydride, Alky I and Aryl Complexes Table 4 R

Me

[NiX(R)L2] Complexes3

X

Ligand

Cl Br I CN NCS succinimide phthalidimide OCOMe acac OPh

. OC6H4Ph-/7 OC 6 H 4 Me-/? OC 6 H 4 CN-p Ph 2 C=CMeO Et Cl CN succinimide phthalidimide N(BEt 3 )=CHBu t N(BEt3)=CHPh OPh OC 6 H 4 CN-/> OCOMe OCOEt acac NiCH 2 CH 2 CO 2 «-C 6 H, 3 Br CH 2 CHCMe 2 CHMe 2 CH— OPh —CH 2 CHMeCONH— —CH 2 CH(C 5 H 8 )CHCO 2 — —CH2CMeCH(Pr)N=CHCH=N(C7H5) —C(CF 3 ) 2 OC(CF 3 ) 2 O—

Me 3 SiCH 2

Cl Br I NCS NCO

PhCMe 2 CCH 2

Cl Br I NCS NCO

PhCMe 2 CH 2 PhOCOCH 2 PhC(Me)H PhCH 2

Cl Br Cl Cl

PMe 3 a PMe 3 a PMe 3 a PEt 3 PCy 3 MeCN PMe 3 PEt3 diphos bipy PEt 3 diphos bipy PMe 3 PPh 3 PEt 3 PMe 3 PMe 2 Ph diphos bipy PEt 3 PMe 3 bipy PMe 2 Ph PPh 3 PEt 3 bipy bipy bipy bipy bipy bipy bipy bipy bipy bipy PPh3 bipy PCy 3 PCy 3 Br CNBu 1 , CCNEt^NHBu 1 CNBuS C(NC 4 H 8 )NHBu 1 CNPr1, C(NEt 2 )NHPr j PMe 3 PMe 2 Ph PMe 3 PMe 2 Ph PMe 3 PMe 2 Ph PMe 3 PMe 2 Ph PMe 3 PMe 2 Ph PMe 3 PMe 2 Ph PMe 3 PMe 2 Ph PMe 3 PMe 3 PMe 2 Ph PMe 3 PMe 2 Ph PEt 3 PPh 3 PPh 3 PBu 3

Ref. 10-12,53,56, 144, 145 10,56,144 10,56,144 311 262 311 56 298 298,304 298,304 298 298 298 11 21,113,152,162 405 11 8 405 405 405 11 405 89 171 311 298,304 298,304 265 265 405 405 304 303 110 416 17 257 276 241 129, 155 40 40 40 421 421 421 421 421 421 421 421 421 421 421 421 421 421 421 421 421 421 421 280 17 17 142

Nickel Hydride, Alkyl and Aryl Complexes Table 4 R

X

Br

CH2=CH CH2=CHCH=CH fra/w-PhCH=CH

CN Cl Br Cl Cl Cl CN Br Cl Br

c/5-PhCH=CH

Br

m-PhC(Me)=C(Me)

Br

—CH 2 C 6 H 4 CH2— Ph 2 CH p-ClC 6 H 4 CH 2 m-O 2 NC 6 H 4 CH2 p-O 2 NC 6 H 4 CH 2

Ph 2 PC 6 H 4 C=CHC 6 H 4 PPh 2 (o-MeC 6 H 4 ) 2 PC 6 H 4 C=CHC 6 H 4 P(C 6 H 4 Me-o) 2

CF2=CF

—CH2CHC2H4CHC2H4CH=CH2 Cl

C1 2 C=CC1

Cl Br

Me(ButN=C)3 PhCH2(BulN=C)3 MeCO(ButN=C)4 PhCO(ButN=C)5 Et(BulN=C)3 Pr(BulN=C)3 Pri(ButN=C)3 Me2C(OH)C=C

Br2 I Cl Cl Cl Cl I I I NCS

C6H,0OHC=C

NCS

Et(Me)COHC=C

NCS

Me(H)COHC^C CH2OHC=C PhCHOHC=C CH2=C(Me)C=C

NCS NCS NCS NCS

MeCOC=C PhC=C

Br NCS

Ph

SnMe 3 NO Cl

Br

I

55

{continued) Ligand PPh3 bipy PPh 3 bipy PEt 3 PPh3 PPh 3 bipy bipy bipy bipy PEt 3 PEt 3 PEt 3 PPh3 PEt3 PPh 3 PEt 3 PPh 3 Cl Cl Br I OPF 2 O PEt 3 PPh 3 a PEt 3 a PMe 2 Ph a PEt 3 PMe 2 Ph a PMe 2 Ph PEt3a CNButa CNBu* CNBu 1 CNButa CNBu 1 CNBu* CNBu 1 PBu 3 PPh 3 PBu 3 PPh 3 PBu 3 PPh 3 PPh 3 PPh 3 PPh 3 PBu 3 PPh 3 PBu 3 PBu 3 PPh 3 PPh 3 PPh 3 PEt 3 PEt2Ph PBu2Ph PPh 3 a P(C 6 H 4 Me-p) 3 P(Obornanyl)3 bipy PEt3 PPh 3 a PPh 2 C 4 H 8 PPh 2 bipy PEt 3

Ref. 50, 77, 306 77,90, 142,415 17,77,306 90 311 414 17 415 415 415 415 309 253,277,309 35 35 35 35 314 314 27, 121 121 121 121 399 253 24 6, 42, 63, 115, 253, 320 272,302,313 42,63,253 272 272 63 17 17 17 17 17 17 17 387 387 387 387 387 387 387 387 387 387 387 256 387 288,387 2 388 253,309 14 14,342 137, 138, 156,317, 396, 397 64 65 109 136,309,315,345 17, 137,138,309,314, 396, 397, 399 81,315 109 373

Nickel Hydride, Alky I and Aryl Complexes

56

Table 4 R

X

CN

o-MeC 6 H 4

PPh 2 CHC(Ph)O acac NO Cl Br

m-MeC 6 H 4

I Cl

/?-MeC 6 H 4

Cl

O-C1C6H4

I Br I Cl Cl Cl Cl Cl Cl Cl Br I CN Cl Br I CN Cl

m-ClC 6 H 4

Br CN Cl

/7-ClC 6 H 4

Cl

polystyrene o-?/ww-MeCH=CHC 6 H 4 o-m-MeCH=CHC6H4 o-CH2=CHCH2C6H4 o-PhC 6 H 4 —C 6 H 4 -o-C 6 H 4 — o-CF 3 C 6 H 4 w-FC6H4

p-FC 6 H 4

m-CNC 6 H 4 p-CNC6H4

o-MeCOC 6 H 4 /7-MeCOC 6 H 4

p-Me 2 NC 6 H 4 o-NO 2 C 6 H 4 o-MeCOC 6 H 4 m-MeCO 2 C 6 H 4 />-MeCO 2 C 6 H 4 /7-MeCOC 6 H 4 />-PhCOC 6 H 4

Br Cl Cl Br N3 NCO NCS Br Cl Br N3 NCO NCS Br Cl Br Cl Cl I Cl I Cl Br

{continued) Ligand PPh 3 bipy PEt 3 PCy 3 PPh2C4H8PPh2 PPh 3 (45) PEt 3 PPh 3 (39) PPh 3 a bipy PEt 3 PPh 3 diphos PPh 3 PPh 3 a bipy PPh 3 a bipy PPh 3 PPh 3 PPh 3 PEt 3 a PEt 3 PEt 3 a PEt 3 a PEt 3 PPh 3 PEt 3 PEt 3 PEt 3 PEt 3 PEt 3 PEt 3 PEt 3 PEt 3 PEt 3 PPh 3 bipy PEt 3 PPh 3 PEt 3 PPh 3 PEt 3 PPh 3 a PEt 3 a PPh 3 PPh 3 PPh 3 PPh 3 PPh 3 PPh 3 PPh 3 PEt 3 PCy 3 PPh 3 PPh 3 PPh 3 PPh 3 PPh 3 PEt 3 PPh 2 (Me)(?) PPh 3 PPh 3 PEt 3 PEt 3 PPh 3 PEt 3 PPh 3 PPh 3

Ref. 138,396,397 109 135,286,311 287 84 296 198,200 102 156 109 315,346 150,271 315 271 64,137,156 109 64,137,156 109 137 319 319 63 63 63 7,74 7,74 156 67 67 67 67 67 67 67 67 24, 115,278,309 321 109 309 317,321 309 137 309 64,137,156 309 137 79,137 79 79 79 79 323 79 79 79,137 79 79 79 79 374 323 323 137 373 373 137 373 137 137

Nickel Hydride, Alky I and Aryl Complexes Table 4 R

{continued)

X

/?-MeOC 6 H 4

I Br I Cl

m-PhOC 6 H 4 /?-PhOC 6 H 4 1-naphthyl

Br I Cl Cl Cl

o-MeOC 6 H 4

Ligand

Br CN t

t

Bu 2 PCH2C6H 3 CH 2 PBu 2 2,6-Me 2 C 6 H 3 2,6-(MeO) 2 C 6 H 3 2,5-Cl 2 C 6 H 3 NiC 6 H 4 CO 2 mesityl

Br Cl Cl Cl Br I N3

2,3,6-Cl 3 C 6 H 2

NO2 NCS Cl

2,4,6-Cl 3 C 6 H 2

NO2 NCS NCS Cl Br I N3 NO2 NCO NCS

2,3,4,5-Cl 4 C 6 H

Cl

2,3,4,6-Cl 4 C 6 H

Cl

2,3,5,6-Cl 4 C 6 H

Cl

C6F5

NO2 NCS F Cl Br

•

PEt3 PEt 3 PEt 3 PPh 3 a PEt 3 PPh3 PEt 3 PPh 3 PPh 3 PCy 3 PPh 3 PPh 3 a PCy 3 Cl CN PEt 3 PMe 2 Ph PEt 3 a bipy PEt 3 a PMe 2 Ph a PEt 3 a PEt 3 PEt 3 PMe 2 Ph PEt 3 PEt 3 PEt 3 PPh 3 diphos PEt 3 PEt 3 PEt 3 ,7-pic PEt 3 PPh 3 diphos PPh 3 diphos PPh 3 diphos PPh 3 diphos diphos PPh 3 diphos PPh 3 diphos PEt 3 PPh 3 diphos PEt 3 PPh 3 diphos PEt 3 PPh 3 diphos PEt 3 PEt 3 PEt 3 PEt 3 a PPh 3 a AsPPh 3 PEt 3 a PPh 2 Me PPh 3 a

I

57

AsPh 3 PPh 3

Ref. 373 345,374 374 137,356 373 137 373 137 137 317 156,317 17,301 317 147 147 253 252 24,309 416 42,253,261 252 261,267 261 261 252 261 261 251 305 305 251 251 251 251 305 305 305 305 305 305 305 305 305 305 305 305 305 251 305 305 251 305 305 251 305 305 251 251 279,309 57,309 285 285 136,297,309,311, 312,'405 3 13,78,115,285,308, 312 285 285,308

Nickel Hydride, Alky I and Aryl Complexes

58

Table 4 (continued) X

R CN

c6ci5

NO 2 NO3 NCS CIO4 Cl

Br

Br2 I

CN N3 NO2 NO3 NCO NCS

OC 6 C1 5 OCOMe OC1O3

MeCO

Cl

EtCO Me 3 CCH 2 CO 1-adamantylCO Me 3 CCO Me 3 SiCH 2 CO

Br I OC 6 H 4 CN-/> OCOMe OC 6 H 4 CN-p Cl Cl Br Cl Br I NCS NCO

Ligand AsPh 3 PEt 3 PPh 3 PPh3 PPh3 PPh 3 PPh 3 PEt 3 a PEt 3 , PPh3 PMe 2 Ph a PPh 2 Me a PPh 3 a diphos bipy py py, PPh 3 a-pic, PPh 3 /8-pic, PPh 3 7-pic, PPh 3 2,4-lut, PPh 3 PEt 3 PMe 2 Ph a PPh 3 a diphos PMe 2 Ph PMe 2 Ph a PPh 3 a diphos PEt 3 PMe 2 Ph diphos PEt3 PPh 3 diphos PEt3 diphos bipy diphos PEt 3 PPh 3 diphos PEt 3 PMe 2 Ph PPh 3 diphos bipy PEt 3 diphos PMe 2 Ph PPh 2 Me diphos PMe 2 Ph PPh 2 Me PPh3 diphos PMe 3 PEt3 PMe 3 PMe 3 bipy PMe 3 bipy PEt3 PEt 3 PEt3 PMe 3 PMe 3 PMe 3 PMe 3 PMe 3

Ref. 285 311 308 308 308 308 308 251 392 98, 111, 160,255,422 111, 160,255 78, 82 83 119 392 392 392 392

392 392 251 160,272 78,82 83 272 160 78,82 83 251 255, 274 83 251 78,82 83 251 83 119,260 119 251 78,82 83 251 160 78, 82, 308 83 260 251 119 160,255 255 119 255 255 308 119 10, 139, 144, 145 278,309,391 10, 144 10, 144 405 144 405 278,309,391 253,278,309,391 278,309,391 421 421 421 421 421

Nickel Hydride, Alkyl and Aryl Complexes

59

Table 4 {continued) R

X

PhCMe2CH2CO

Cl Br I NCO F Cl

PhCO

Br CN O-C1C 6 H 4 CO W-C1C 6 H 4 CO p-ClC6H4CO MeOCO EtOCO PhCH2OCO NiCOC6H4CO2 NiCOC2H4CO2 a

Cl Cl Cl Cl Cl Cl

Ligand PMe3 PMe2Ph PMe3 PMe3 PMe3 PEt3 PEt3 P(Obornanyl)3 PEt3 diphos PEt3 PCy3 PEt2C4H8PEt2 PEt3 PEt3 PEt3 PPh3 PPh3 PPh3 bipy bipy

Ref. 421 421 421 421 421 278,309,391 253,278,309,391 65 278,309,391 81 425 425 425 278,309,391 278,309,391 278,309,391 17 17 17 416 416

Earlier work is discussed and tabulated in ref. 1, pp. 168-206. Table 5 R

Me

Et

Pr Me3SiCH2 NCMe2C —CH2(CH2)2CH2—

—CH2(CH2)3CH2— —CH2(SiMe2)2CH2— —CH 2 (C=CH 2 ) 2 CH 2 — —CH2C6H10CH2— —CHCMe2CHCHCMe2CH— —(norbornyl)2— —CPh=CPhCPh=CPh— —CF2(CF2)2CF2—

[NiR2L2] Complexes and [NiR2L3] Complexes3 Ligand (L) [NiRiLiI Complexes PMe3a PMe3, CH 2 =PMe 3 PEt3 PBu3 diphosa Ph2PC3H6PPh2 bipya Me 2 C 6 H 3 N=NHNH=NC 6 H 3 Me 2 Me 2 C 6 H 3 N=NMeNMe=NC 6 H 3 Me 2 Pr i 2 C 6 H 3 N=NHNH=NC 6 H 3 Pr i 2 Pr i 2 C 6 H 3 N=NMeNMe=NC 6 H 3 Pr i 2 Pr i 2 CHN=NHNH=NCHPr i 2 PBu3 diphos bipya bipy bipy PPh3 PBu3 PCy3 PPh2Me PPh2CH2Ph PPh3 diphos bipy (46) PPh3 PPh3 PCy2C2H4PCy2 (48) PPh3(50) bipy (49) bipy (47) diphos (42) PCy2C2H4PCy2 (PPh2CH2)3CMe (AsPh2CH2)3CMe P(OC6H4Me-o)3

Ref. 53 53 113,254 113 113,254,394 394 22, 161, 163,254, 304, 324 390 390 390 390 390 113 113,254 22,161,163,254, 275, 304, 380, 417 161,254 300 367 290 290,310 87,290 290 87,263,290,291 87,290,310 131, 158,325 264 301 266 292 131,257,307 131,258 339 339 322 322 369

Nickel Hydride, Alkyl and Aryl Complexes

60

Table 5

R

(continued)

Ligand (L)

Ref.

o-MeC6H4CH2 o-FC6H4CH2

PPh3a CNBu', C(NMe2)NHBut CNBu1, C(NEt2)NHBul CNBu1, C(NHBul)2 CNBu1, C(CN4H8O)NHBut CNPr1, C(NMe2)NHPrj CNPr\ C(NEt2)NHPrj CNBu1, C(NMe2)NHBut CNBu1, CCNEt^NHBu* CNBu*, C(NHBut)2 CNBu1, C(NC4H8O)NHBut PCy3 P(OMe)3a(53) AsMe2Pha PBu3 PBu3

O-C1C 6 H 4 CH 2

PEt3

51,92

PBu3 PEt3 PBu3 bipy

51,92 92 92 90 60 372 389 387 256 256 256 256 256

—CF2CF=CFCF2—

-C(CF 3 )[C(CF 3 )]4C(CF3)-

o-BrC6H4CH2 0-Ph2PC6H4CH2a o-C6H4-pyrazolyl (44) HC=C HOCH 2 C=C EtOCH 2 C^C

PhOCH 2 C=C

PBu3 PBu3 PBu3 PCy3 PBu3 PCy3 PCy3

O-C1C6H4OCH2C=C

PBu3

MeCOC=C MeCH(OH)C=C Me 2 COHC=C EtC(Me)OHC=C C 6 H 10 OHC=C PhO^C

PBu3 PBu3 PBu3 PBu3 PBu3 PEt3a PBu3a PCy3 PPh3a PBu3 PPu3 PBu3 PBu3 PBu2Ph PEt3a PEt3

BuOCH2C=C

(—C=C-/7-C6H4—C=C—)„ o-HC 2 C 6 H 4 C=C HC=C—C=C —(C=C—C=C)—„ Ph c?-MeC6H4 o-Ph2PCH2C6H4 —C6H4O(CH2)4OC6H4— o-MeOC6H4 2,6-Me2C6H3 2,6-Me2C6H3 2,6-Me2C6H3 mesityl 2,6-(MeO)2-3-BrC6H2 2,6-(MeO)2-3,5-Br2C6H C6F5

PEt3 PEt2Ph PEt3 PEt3 PEt3 PMe2Ph PEt3a PMe2Ph PMe2Ph dioxane toluene PEt3a PBu3 PPh2H PPh2Cl PPh3a diphos AsPh3 SbPh3 OPPh3 OAsPh3

322 40 40 40 40 40 40 40 40 40 40 126 29,124,166 29 92 92

256

256 256 256,387 387 256,387 42,75,253 256, 288, 387 256 288 389 329 389 38972 374 281 282 316 316 345,374 253 253 273 267,281 273 273 16,283,284 268,297 16,268,297,405 16 405 283 16 283 16 16 16 16

Nickel Hydride, Alky I and Aryl Complexes Table 5

{continued)

R

Ligand (L)

Ref.

NH 3 py en bipya phena bipy bipy [N1R2L3] Complexes PMe3 PMe2PH bipy, CH 2 =CHCN a bipy, CH2=CHCHOa PPhs

—C(O)CMe=CMeC(O)— —C(O)CP=CPh(O)— Me Et —CH2(CH2)2CH2—

283 283,405 283 283 283 420 420 11,18,53 8,89 161 161 87,259,263,289291,310 264 80, 125 126 29,124,166 29

—CH2(CH2)3CH2—

PPh3 —CH(CO2Et)Ntetraphenylporphyrin (58) -C(CF 3 )[C(CF) 3 ] 4 C(CF 3 )PCy3 P(OMe)3a AsMe2Pha a

61

Earlier work is discussed and tabulated in ref. 1, pp. 168-206. Table 6 R'

R Me

Ph o-MeC6H4 o-MeOC6H4 m-FC6H4 p-FC6H4 mesityl —CCH 2 CH;»CH 2 CCH 2 CH 2 CH 2 — —CCH 2 CH 2 CH 2 C(=CH 2 )CH 2 CH 2 — —CPh 2 COOC(=CPh 2 )—

MeC(OMe)=CH CH 2 =C(OMe) CH 2 =C(OEt) CH 2 =C(OPr) OC2H4CH=C— OCH=CHCH=C— OCMe=CHCH=€— SCH=CHCH=C— Br 2 C=C(OMe) HCCl=C(OMe) MeCBr=C(suc) MeN=C(OMe) C1 2 C=CC1

HC=C HOCH2C=C MeOC EtC=C HOC 2 H 4 C=C PhC=C

[NiR(R / )L 2 ] Complexes3

C6C15

c6ci5 C 6 C1 5

c6ci5 c6ci5 c6ci5 c6ci5 c6ci5

C 6 C1 5

c6ci5

C 6 C1 5

c6ci5

2,6-(MeO) 2 C 6 H 3 2,6-(MeO)2-3,5-Br2C6H HC=C MeC=C PhC=C /7-MeOC 6 H 4 C=C 2,6-(MeO) 2 C 6 H 3 mesityl

c6ci5 c6ci5

mesityl C6C15 C6C15 mesityl C6C15 2,6-Me 2 C 6 H 3 2,6-(PBu l 2 CH 2 ) 2 C 6 H 3 2,6-(MeO) 2 C 6 H 3

Ligand

Ref.

PEt 3 PEt 3 PEt 3 PEt 3 PEt 3 PEt 3 bipy bipy Me 2 NC 2 H 4 NMe 2 (54) py PMe2Ph PMe2Ph PMe2Ph PMe2Ph PMe 2 Ph PMe2Ph PMe2Ph PMe2Ph PMe2Ph PMe2Ph PMe2Ph PMe2Ph PMe2Ph PMe2Ph PMe2Ph PMe2Ph PMe2Ph PMe2Ph PMe2Ph PMe2Ph PMe2Ph PMe2Ph PMe2Ph PMe2Ph PMe2Ph PMe2Ph PMe2Ph PEt 3

315,345 281,313,315,345 345 67 67 42, 253 131 131 294 294 299 98, 273, 299, 422 98, 299 299 299 313 313 313 273 273 273 274 273 273 252 252 252 252 252 252 98, 273, 299, 422 299 252 273, 299 299 252 299 253 147 252

PMe2Ph

Nickel Hydride, Alkyl and Aryl Complexes

62

Table 6 R

R'

p-MeOC6H4C=C BrC=C Ph o-MeC 6 H 4 w-MeC6H4 p-MeC 6 H 4 /?-ClC 6 H 4 /7-Me 2 NC 6 H 4 /?-MeOC 6 H 4 C 6 C1 5 /?-MeC 6 H 4 CO p-Me 2 NC 6 H 4 CO /7-MeOC 6 H 4 CO a

(continued) Ligand

mesityl C6C15 mesityl C6C15 C6C15 m-FC 6 H 4 />-FC 6 H 4 C6C15 C6C15 C6C15 C6C15 C6C15 C6C15 C6C15 MeO 2 C MeO 2 C EtO 2 C C6C15 C6C15 C6C15

Ref.

PMe 2 Ph PMe 2 Ph PMe 2 Ph PMe 2 Ph PMe 2 Ph PEt 3 PEt 3 PMe 2 Ph PMe 2 Ph PMe 2 Ph PMe 2 Ph PMe 2 Ph PMe 2 Ph PMe 2 Ph PMe 2 Ph PPh 2 Me PMe 2 Ph PMe 2 Ph PMe 2 Ph PMe 2 Ph

252 299,422 252 299 273 67 67 313 313 313 302,313 313 302 302,313 255,274 255 255 302 302 302

Earlier work is discussed and tabulated in ref. 1, pp. 168-206. Table 7

R

Me

Et PhCH 2

MeCO EtCO PhCO

Ph

mesityl

2,4,6-Cl 3 C 6 H 2 2,3,5,6-Cl 4 C 6 H

[NiRL w ] + X" Complexes

nL 4PMe 3

2 C H 2 = P M e 3 , 2PMe 3 (PPh 2 C 2 H 4 ) 3 N (AsPh 2 C 2 H 4 ) 3 N (PPh 2 C 2 H 4 ) 3 P (PPh 2 C 2 H 4 ) 2 PPh tetramethylcyclam (PPh 2 C 2 H 4 ) 3 N (AsPh 2 C 2 H 4 ) 3 N (PPh 2 C 2 H 4 ) 3 P (PPh 2 C 2 H 4 ) 3 N (AsPh 2 C 2 H 4 ) 3 N (PPh 2 C 2 H 4 ) 3 P (PPh 2 C 2 H 4 ) 2 PPh (PPh 2 C 2 H 4 ) 3 N (AsPh 2 C 2 H 4 ) 3 N (PPh 2 C 2 H 4 ) 3 N (AsPh 2 C 2 H 4 ) 3 N (PPh 2 C 2 H 4 ) 3 N (AsPh 2 C 2 H 4 ) 3 N (PPh 2 C 2 H 4 ) 2 PPh (AsPh 2 C 2 H 4 ) 3 N (AsPh 2 -o-C 6 H 4 ) 3 As 2(o-Me 2 As) 2 C 6 H 4 3PMe 2 Ph 2PMe 2 Ph, P(OMe) 3 2PMe 2 Ph, a-pic 2PMe 2 Ph, 0-pic 2PMe 2 Ph, 3,4-lut 2PMe 2 Ph, 3,5-lut 2PMe 2 Ph, NC 5 H 4 CO 2 Me 2PMe 2 Ph, NC 3 H 3 NEt 2PMe 2 Ph, NCMe 2PMe 2 Ph,C(OMe)Me diphos, 7-pic 2PEt 3 , 7-pic

X

Ref.

BPh 4

56,93,145

NCS Cl Br I

56

O 2 PMe 2

56 53 4 4 4 269 127 4 4 4 4 4 4 269

Cl BPh 4 (41) BPh 4 BPh 4 BPh 4 CF 3 SO 3 (43) BPh 4 BPh 4 BPh 4 BPh 4 BPh 4 BPh 4 BPh 4 BPh 4 BPh 4 BPh 4 BPh 4 BPh 4 BPh 4 BPh 4 BPh 4 BPh 4 BPh 4 C1O4 C1O4 C1O4 C1O4 C1O4 C1O4 C1O4 C1O4 C1O4 CIO4 C1O4 C1O4

18,56 18,56 18,56, 145

122,153

122 122 122 122 122 269 41, 151

151 151 252 252 252 252 252 252 252 252 252 252 305 251

Nickel Hydride, Alkyl and Aryl Complexes Table 7 R C6F5

C6C15

63

{continued)

nL 3PPh 3 2PPh 3 , PEt 3 2PPh 3 ,PBu l 3 2PPh 3 ,AsPh 3 2PPh 3 ,py 2PPh 3 , OPPh 3 2PPh 3 ,SPPh 3 2PPh 3 , H 2 O 2PPh 3 , Ch 3 NO 2 2PEt 3 ,C 3 H 4 N 2 2PEt 3 ,py 2PEt 3 ,a-pic 2PEt 3 ,j8-pic 2PEt 3 ,7-pic 3PMe 2 Ph 2PMe 2 Ph, NCMe 2PMe 2 Ph,NCCH 2 Ph 2PMe 2 Ph,NCPh 2PMe 2 Ph, N H = C ( M e ) O M e 2PMe 2 Ph, N H = C ( B z ) O M e 2PMe 2 Ph, N C = C ( P h ) O M e 2PMe 2 Ph, N H = C ( M e ) O E t 2PMe 2 Ph, C(NHMe) 2 2PMe 2 Ph,C(NHMe)NMe 2 2PMe 2 Ph, C(OMe)NHMe 2PMe 2 Ph, C(OEt)NHMe 2PMe 2 Ph,C(OMe)NMe 2 2PMe 2 Ph, C(OMe) 2 2PMe 2 Ph, C(Me)OMe 2PMe 2 Ph, C(Me)OEt 2PMe 2 Ph, C(OPr)Me 2PMe 2 Ph, C(CH 2 ) 3 O 2PMe 2 Ph, C(OMe)C 6 H 4 -/>-NMe 2 2PMe 2 Ph, C(OMe)C 6 H 4 -p-OMe 2PMe 2 Ph, C(OMe)C 6 H 4 -/>-Me 2PMe 2 Ph, H 2 O 2PMe 2 Ph, CO 2PMe 2 Ph, P(OMe) 3 2PMe 2 Ph, 3,5-lut 2PPh 2 Me,CO 2PPh 2 Me,NCMe 2PPh 2 Me, NCCH 2 C 6 H 5 2PPh 2 Me,NCPh 2PPh 2 Me,NH=C(Me)OMe 2PPh 2 Me,NH=C(Bz)OMe 2PPh 2 Me, 3,5-lut diphos, py diphos, C 3 H 4 N 2 diphos, Me 2 C 6 H 3 N diphos, a-pic diphos, jS-pic diphos, 7-pic 3(3,5-lut) bipy, py bipy, PPh3

X C10 4 CIO4 CIO4 CIO4 C1O4 C1O4 CIO4 CIO4 CIO4 C1O4 C1O4 CIO4 CIO4 CIO4 C1O4 C1O4 SO 3 F PF 6 C1O4 C1O4 C1O4 C1O4 C1O4 C1O4 PF 6 PF 6 C1O4 C1O4 C1O4 PF 6 C1O4 C1O4 C1O4 C1O4 C1O4 C1O4 C1O4 C1O4 C1O4 C1O4 C1O4 C1O4 C1O4 C1O4 C1O4 C1O4 C1O4 C1O4 C1O4 C1O4 C1O4 C1O4 C1O4 C1O4 CIO4 C1O4 C1O4

Ref. 308 308 308 308 308 308 308 308 308 251 251 251 251 251 255 160,274 274 274 160 160 160 160 160 160 274 274 274 274 274 274 98,299,422 98,299 299 299 302 302 302 255 255 160 111 255 160 160 160 160 160 111 119 119 119 119 119 119 111 260 260

37,4.3.3,1 Preparation and structure The bis-ligand nickel alkyl and aryl complexes are most conveniently prepared by reacting an organomain group metal reagent with the appropriate nickel dihalide or by oxidative-addition or -substitution reactions with zerovalent nickel complexes. A brief discussion of these two pro-

64

Nickel Hydride, Alky I and Aryl Complexes

cedures is followed by that of a number of less common methods. The ionic complexes listed in Table 7 have been prepared in general by reacting a suitable [NiX(R)L2] complex with further ligand molecules.

(/) Reactions with organomain group metal reagents The most commonly used reagents are organomagnesium compounds (equation 62)4,51,63,67,82,83,92,127,129,251,269,301,305,315,345,372,374,390,421 O f organolithium Compounds (equation 63).7,11,18,67,74,82,87,102,147,252,264,273,282,290-292,302,310,313,315,316,339,345,374 O t h e r reagents w h i c h

have been used include organoaluminium, 6 ' 8 ' 21 * 63 ' 171 ' 300 ' 320 ' 366 organopotassium,60'326 organosodium, 256 ' 265388 organothallium 285 and organomercury 327 complexes. Although the reaction is normally carried out using nickel(II) salts, examples have been reported involving monovalent nickel compounds, e.g. (equation 64). 285 The X-ray crystal structure determination of complex (38) shows the nickel to be in a typical square planar environment.3 The unusually short Ni—C bond length [1.880(4) A] is presumably a consequence of the /ra«5-bromine group (significantly larger values are obtained for related complexes in which the pentafluorophenyl group is trans to a second C 6 F 5 [1.939(3) A] or trans to a C6C15 group [1.978(10) A]; see ref. 1, p. 198).

Me3 b.213

[NiCl2(PMe3)2]

+

MgCl(CH2SiMe3)

~MgC'2>

Me3Si-^CHr^Ni%^iCl

(62)

94.1^T 87.6°

2.20T Me3 Br

[NiBr2(PPh2Me)2]

+

LiC6F5

- ^

\2J25 2.216^PPh2Me 89>Ni^5°

MePh 2 P""^i 5 ' ^ C

6

F

(63)

5

(38) 2[NiCl(CO)2(PPh3)2]

+

TlBr(C6F5)2

—* 2[NiCl(C6F5)(PPh3)2]

+

TlBr

+

4 CO

(64)

Unusual complexes prepared by reaction with organomain group metal reagents include the diamagnetic phenylnickel nitrosyl (39) (equation 65), 102 the heterocyclic binuclear complex (40) (equation 66), 3 3 0 the nickel methyl complex (41) (equation 67), 4 the nickelacyclopentadiene derivative (42) (equation 68), 339 ' 395 the paramagnetic complex (43) (equation 69) I 2 7 and the bis(pyrazolylphenyl)nickel complex (44) (equation 70). 372

[NiBr(NO)(PPh3)2]

+

LiPh

-+

[NiC6H5(NO)(PPh3)2]

+

LiBr

(65)

(39) (PEt3)2 2[NiCl(C6H4Br-oXPEt3)2]

+

4 Li

—*

(QT

T O

(PEt3)2 (40)

+

2LiBr

+

2LiC1

(66)

Nickel Hydride, Alkyl and Aryl Complexes

[NiBr(PPh2C2H4)3N]+

+

MeMgBr

^H+

65

2U

/ P h 2 J>

(67)

H2.02

Me (41) ?h

Ph2

r

\

I

Li"V

NiBr2

+

Ph2 P h

Ph

^ \

I

—

J^/Ph

Ni

I

+

2LiBr

(68)

(42)

Me f ^ ] yMe f (2+)Ni

M/

J

Me f ^ +

Me2Mg

—•

Me

f (+)Ni

J—Me

(69)

Me7 l^J Me

I^J Me

(43)

[NiBr2(PPh3)2]

+

2 A^MgBr

^"3^

l / l

Y

+

2 MgBr2

(70)

(44)

(//) Oxidative-addition or -substitution Oxidative addition to zerovalent nickel complexes is now the most important method for preparing monoalkyl or monoaryl complexes and a recent review is found in ref. 25. The most popular reagents are bis(cyclooctadiene)nickel in the presence of ligand molecules (equations 71, 72),7,50,65,74,77,90,131,136,.58,266,276-279,296,307,309,325,416

[ N i L 3 ] o r [ N i L 4 ] c o m p l e x e s (equation 7 3 ) 6,17,35,50,67,81,84,136,137,145,167,262,277,279,309,317,319,321,323,373,374,396,397 Bis-Hgand nickel m o n o -

alkene complexes (in particular those of ethylene) have also been used,24-65'77'166'263'287-306-309'414 while finely divided nickel 13 - 57 ' 258 ' 268 ' 297 ' 312 ' 405 is proving useful for the syntheses of less stable complexes. Related to these are electrolytic methods using a nickel anode. 115 ' 31 li396 ' 397

[Ni(cod)2]

+

2PEt 3

[Ni(bipyXcod)]

+

+

^

^

[ Q ^ )o

II [Ni(PPh3)3]

+

ClCO2Me

—•

—•

—•

VNiCl(PEt 3 ) 2

(bipy)Ni^

/ ^ C

+

2 cod

(71)

+

cod

(72)

+

PPh3

(73)

\>

[NiCl(CO2Me)(PPh3)2]

66

Nickel Hydride, Alkyl and Aryl Complexes

The mechanism of the oxidative addition of organic halides to zerovalent nickel phosphine complexes has been discussed by several authors.35'118,137,309,373 j ^ reaction between tetrakis(triethylphosphine)nickel and aryl halides has been studied in some detail373 and it could be shown that a nickel(I) species, [NiXL 3 ], is formed in addition to the expected arylnickel halide. The relative yield of these products is influenced by the nature of the halide and the solvent and by the presence of polar substituents on the aryl group. The reaction is found to be first order in both nickel component and aryl halide and a mechanism involving initial dissociation to give a trisphosphine nickel species followed by electron transfer to give a paramagnetic ion pair has been proposed (Scheme 1). This mechanism is supported by electrochemical measurements which demonstrate that the zerovalent nickel phosphine complex undergoes a ready 1-electron oxidation. Reactions involving acyl halides and vinyl halides may well proceed by an initial 7r-coordination to the metal (equation 74). The observed retention of stereochemistry in the reaction involving cis- and trans-fi-bromostyrem is in accord with this suggestion.35 [Ni(PEt3)4]

[Ni(PEt3)3]

+

ArX

—^

^

[Ni(PEt3)3]3

[Ni(ArXMPEt3)3]

+

PEt3

r-+ [NiX(Ar)(PEt3)2] -I *—* [NiX(PEt3)3] +

+

PEt3

Ar*

Scheme 1

[Ni(PEt3)3]

+

RCOX

^*-

(Et 3 P) 2 Ni^J

-~•

[NiX(COR)(PEt3)2]

(74)

This mechanism may, however, be limited to triethylphosphine and related alkylphosphines. Kinetic evidence suggests that the mechanism of the reaction of tris(triphenylphosphine)nickel with aryl halides depends upon the nature of the substituents on the aryl group, and a concerted three-centre process reminiscent of aromatic nuclepphilic substitution has been suggested.137'373'378 Unusual complexes formed by oxidative addition include (45), in which a delocalized chelating ligand derived from an ylide is complexed to nickel (equation 75), 296 and the nickelacyclopentane complex (46) (equation 76). I 3 1 1 5 8 ' 3 2 5

Ph p>

Phv

[Ni(cod) 2 ]

+

PPh 3

+

Ph 3 P=CHC(Ph)O

~2c°d>

1.893V 2168 /< CH 9i.7-.NU6.5- | 2.230X X ^CPh Ph3P

(75)

x ,.9i4 or (45)

I < ^ N I-959 K 9 ^sl.52

2[Ni(cod)2]

+

4bipy

+

Br(CH2)4Br

_fa^Bra»

T s i . l ^ N i ^ . s Ji.49

(76)

(46) Complexes related to (46) may also be formed by the dimerization of alkenes at nickel. This reaction was initially believed to be limited to perfluoroalkenes such as tetrafluoroethylene (equation 77; see also ref. 1, p. 172),322'369 or strained alkenes such as norbornadiene (equation

Nickel Hydride, Alky I and Aryl Complexes

67

78) 131,258 a n e n e (equation 79), 266 3,3-dimethylcyclopropene (equation 80)131,257,307 a n ( j m e t } 1 . ylenecyclopropane (equation 81 ), 131 but recently it has been shown that, under suitable conditions, ethylene (equation 82) 263 and 1,7-octadiene (equation 83) 292 also react to give nickelacyclopentane systems. Mechanistically related are the reactions between tris(triphenylphosphine)nickelacyclopentane and various alkenes, which leads to formation of new five-membered ring complexes, 289 ' 292 the insertion of hexafluoropropylideneamine or hexafluoroacetone into the hexafluoroacetone complex (51) (equation 84; see ref. 1, pp. 172, 199) and the reaction of the trifluoromethylacetylene complex (52) with further alkyne (equation 85). 29 ' 124 ' 126 ' 166 The crystal structure of (53) indicates that the nickel atom is in a distorted trigonal bipyramidal environment [the bond lengths shown in equation (85) are for the P(OMe)3 complex; the complex where L is AsMeaPh has also been isolated] and interacts with the central C atoms of the nickelacycloheptatriene ring. F2 [Ni(AsPh2CH2)3CMe(CF2=CF2)]

+

CF 2 =CF 2

—•

MeC(CH2Ph2As)3Ni^ X

I


2

(77)

2

F2

(47)

Cy2 f

Ni(cod)

Cy2 +

2CH 2 =C=CH 2

hlvfiyNW 50 P 47

^ ^

Cy2

(79)

Cy2 (48)

X

::£2

^

^s~>NvL96o y ^ v T ^ T 81.8^Ni(83.6° Jl.47 J ^ X 1.904"^/

(80)

(49)

[Ni(bipyKcod)]

+

[Ni(PPh 3 ) 2 (CH 2 =CH 2 )]

2 j \

+

—*•

(bipy)Ni

CH 2 =CH 2

—•

J

+

cod

(81)

(Ph3P)2NiJ

(82)

68

Nickel Hydride, Alkyl and Aryl Complexes H [Ni(PPh3)2(CH2=CH2)]

+

J

—* (Ph3P)2Ni

T

J

+

CH2=CH2

(83)

(50)

(CF 3 ) 2 (BUWOIN/I N

^'"S^oo^ +

(CF3)2C=NH

1 7

- ^N^.5« 1 |iS)

—•

X

O

Y

B u t N C

(51)

(84)

,.8>
^

CF^CF,

[NiL 2 (CF 3 C=CCF 3 )]

+

2CF 3 C==CCF 3

U. / CCF 3 2 2i5^Ni-a-22-^l.41

—•

<\

(52)

(85)

f^

CF 3 C=icF 3 (53)

An unusual insertion reaction is observed on treating [Ni(7/3-allyl)2] with difluorophosphoric acid in the presence of 1,5-hexadiene (Scheme 2); insertion of the diene into an ?73-allyl group occurs to give a complex in which a nonadiene chain is both w- and
[Ni(773-C3H5)2] +

2 HO2PF2

-—

[{NiO2PF2(C3H5)j2]

TH ^ ±

/ ^Ty°PF2O\ I H-A-Ni( j v

*

2 C2H20

+

>—it

NiBr 2

+

/2 Ni(O 2 PF 2 ) 2

Scheme 2

A novel reaction has been reported between [Ni(bipy)(PhC=CPh)l and CO in which insertion occurs to give the nickelacyclopentene derivative [NiC(=O)CPh=CPhC(=O)(bipy)]. This same complex is also formed on reacting [Ni(bipy)(CO)2] with diphenylacetylene.420 It is appropriate to include here the reaction between diphenylketene and bis(cyclooctadiene)nickel, from which a complex which could be formulated as (54) has been isolated (equation 86).294

Me 2

N

.I

^ \ Ao [Ni(cod)2]

+

2Ph 2 C=C=O

+

Me2NC2H4NMe2

^^^

)Ni

|

V ^° Me

2 Ph Ph (54)

(86)

Nickel Hydride, Alkyl and Aryl Complexes

69

(Hi) Miscellaneous preparative reactions Dehydrohalogenation assisted by an amine or alkoxide is a method particularly useful for preparing nickel alkynyl complexes (equations 87-89).75,98,252,299,329,387,389 This type of reaction is also observed on treating the chelating ligands (55) and (56) with nickel dihalides (equations 90, 9l).27,i2i,i47 \ y j j a t £ 0 ^ b e r e g a r ( jed as related reactions are those of the mm>-tetraphenylporphinato complex (57) with base (equation 92) 80125 (hydrogen abstraction is followed by [NiCl2(PEt3)2]

+

2HC=CPh

[NiCl(C6Cl5)(PMe2Ph)2]

[NiX2(PBu3)2]

+

+

.MeOH^Naei'

HC^CH

2 HC=CC 6 H 4 C 2 H-o

j-ff)

^

[Ni(OE=CPh)2(PEt3)2] [NiC=CH(C6Cl5KPMe2Ph)2]

(88)

^)-C=C—Ni^C=C-^^

(89)

Bu3

,f

H2 C-PBu^

CHiPBu^


(87)

+

NiCl2

^ ^

<^)^Ni-Cl

^CH 2 PBu l 2

(90)

C-PBut2 H2

(55) ^^.PPh2 (Q^

ph

/ r ^ ^ < /H

+

NiCl2

^HO,

u

PhzP^^^

2

F

.C~Ni-Cl

(91)

\Jy

(56) Ph

Ph

^^J_XH2CO2Et ph

—\_ / ^ ^

__/

1^^ Ph

i1

^

Ph—(

/

N

/~Ph

V

(57)

-*

Ph

\

Ph—^

^CCO2Et

/

N i

(58)

\

/

/—Ph

(92)

70

Nickel Hydride, Alkyl and Aryl Complexes

insertion into the Ni—N bond to give a neutral complex (58) whose structure has been verified by X-ray crystallography) and the formal elimination of HBr on treatment of glyoxalbis(fbutylimine)NiBr 2 with o-tolylmagnesium bromide (equation 93). 129 ' 155

W

/ — \

\j_/ N

\ /

o-TolMyBr

Ni

^ L ^ N

1.82aN

(

J^ X"X

-HBr »

\ )—

m )

V

85°N(IOI.2°

/

Deprotonation of cationic nickel carbene complexes (formed by treatment of a nickel alkynyl complex with alcohol in perchloric acid) has been used to prepare substituted vinyl complexes (equation 94).98,252,299,422

[NiC=CH(C6Cl5)(PMe2Ph)2]

| g ^

[Ni=C(Me)OMe(C6Cl5)(PMe2Ph)2]+ClO4[NiC(OMe)=CH2(C6Cl5)(PMe2Ph)2]

^ (94)

Migration of a phenyl or benzyl group from tin (equation 95)14,142,342 o r b o r o n (equation 95)4i,i5i h a s b e e n observed. Phenyl migration is not, however, a general reaction and is not, for example, observed on reaction of Li- or Na-[SnPli3] with [NiCl2(PPh3)2] or with [NiCl(PPh 2 C 2 H4)3N]+BPh4-. In these cases metallation of the nickel occurs. 14 ' 337 ' 342 [NiCl2(PEt2Ph)2]

+

LiSnPh3

^ ^

[NiCl(SnPh3)(PEt2Ph)2] —-* [NiCl(Ph)(PEt2Ph)2]

+

[SnPh2]

(95)

n Ph 2 As-^^8j^l 1.87*^^-AsPh2

A number of examples of alkyl or aryl exchange involving [NiR2L2] and [NiX(R)L 2 ] complexes have been investigated (equations 97-99). 109,301,315,415 Scrambling of the aryl groups in the last reaction indicates that it is more complex than suggested by the equation. [NiCl(C6H4CH2CH=CH2-oXPEt3)2] -^

+

C12C=CC12

[NiCl(CCl=CCl2XPEt3)2]

+

[NiEt2(bipy)]

+

PhCl

—*- [NiCl(Ph)(bipy)]

[NiMe(o-Tol)(PEt3)2]

+

PhBr

— • [NiBr(Ph)(PEt3)2]

C9H8 + +

+

HC1 (97)

C4H10

(98)

C6H4Me2-o

(99)

[NiR 2 L 2 ] complexes can be converted into [NiX(R)L 2 ] complexes by a number of reactions. The most important is controlled protonolysis by inorganic acids (e.g. equation 100), n imides (equation 101) 298 or alcohols (equation 102). 8 ' 257405 Related to these is the Cul-amine catalyzed

Nickel Hydride, Alky I and Aryl Complexes

71

alkyne exchange reaction which has been used to prepare polymeric nickel alkynyl complexes (equation 103). 389 [NiMe(o-Tol)(PEt3)2]

+

HC1 —* [NiCl(o-Tol)(PEt3)2]

O

[NiMe2(bipy)l

+

[NiMe2(PMe2Ph)2] /f[Ni(CsCH)2(PBu3)2]

+

+

CH 4

(100)

O

H N

C^O

+

PhOH

~* (Ql^NiMe(bipy)

-+

[NiOPh(Me)(PMe2Ph)2]

«HC=C—(Cv~~ C^CH

+ CH4

+

(101)

CH 4 (102)

—-

PBu3

PBu3

-f-Ni-C=C-^Q>-C=C-Ni-^/2 PBu3

+

nHC=CU

(103)

PBu3

A reaction which has not been systematically explored is that of disproportionate (equation 104), although the reverse process has occasionally been observed (equation 105). 90 ' 256 [NiR2L2]

+

2[NiBr(C=CR)(PBu3)2]

[NiX2L2]

—* 2[NiX(R)L2]

- ^ 2 ^ [Ni(C=CR)2(PBu3)2]

+

(104) [NiBr2L2]

(105)

The dimeric [{NiX(R)L}2] complexes discussed on p. 51 are readily cleaved on reaction with suitable ligands (equation 106). 11 - 12 ' 385 ' 392 [{NiCl(C6Cl5)(PPh3))2]

+

2py —• 2[NiCl(C6Cl5)(PPh3)(py)J

(106)

Insertion into the Ni—C bond has been observed on treatment with CO 2 (equation 107). 303 The resulting ester is unstable and reacts further with elimination of diethyl ketone. A similar reaction is observed between the V ^ - C g N i complex (59) and CO2 (equation 108). An X-ray structural determination shows that rearrangement of the Cg chain has occurred to give a tetramer in which four [NiO2C9Hi 2 (PCy 3 )] units are so arranged that a 16-membered ring is formed in which each nickel atom is in an essentially square planar environment.241 Diphenylketene insertion into a Ni—Me bond has also been reported (equation 109).89 The structure of the product is not, however, known with certainty. A reaction which may well also proceed by insertion is that of [Ni2(CN)2(PPh2C4H8PPh2)3] with phenylacetylene from which (after protonation) cinnamonitrile has been isolated.381 [NiEt2(bipy)]

+

CO2 — • [NiOCOEt(Et)(bipy)] C

4 "/LJ

+ 4C 2

° -*

(59) [NiMe2(PMe2Ph)3]

+

^ P \2.i46/O:

'f o \

Ph 2 C=C=O

^>

(107)

°o8)

/

[NiOCMe=CPh2(Me)(PMe2Ph)2] (109)

72

Nickel Hydride, Alky I and Aryl Complexes

A rather unusual reaction is that of bis(cyclooctadiene)nickel with azobisisobutyronitrile (equation 110). The initial product is a x-bonded diazene complex from which dinitrogen is eliminated. 367

[Ni(cod)2]

+

2PPh3

+

NCCMe2N=NCMe2CN

~2cod/N2> [Ni(CMe2CN)2(PPh3)2]

(110)

37.4.3.3.2 Reactions The reactions of the [NiR.2Ln] and [NiX(R)L,j] complexes have been divided into three: those in which the Ni—C bond is not involved, those in which new Ni—C bonds are formed, and those in which the alkyl or aryl groups are displaced. (/) Reactions not involving the Ni—C bond Metathetical replacement has been used to prepare whole series of [NiX(R)L 2 ] complexes (equation 11 i).82,83,i 19,251,261,308,421 T h e kinetics of the reaction involving [NiX(mesityl)(PEt3)2] in methanol have been investigated261 and the results suggest that the nucleophilic substitution proceeds by two competing paths: one dissociative, involving the solvent, and the other the direct bimolecular attack by the nucleophile. The metathetical replacement of halide by the cyano group is involved in the catalytic conversion of aryl halides into aryl nitriles (Scheme 3). 317 ' 321 One of the more exotic complexes formed by a metathetical replacement reaction is the iminoborate complex (60) (equation 112). 265 [NiBr(C6F5)(PPh3)2] [NiL4]

+

NaNO 2

4 ^

—>

[NiNO2(C6F5XPPti3)2]

[NiX(Ar)L2]

1

^§|*

+

NaBr

(111)

[NiCN(Ar)L2]

1

a

-ArCN

Scheme 3

[NiBr(Et)(bipy)]

+

Na[Et3BN=CHBut]

~NaBr>

^ N i. 97 .Et 2 0V N i ^f 6 ° ^

(l12)

HC Bul (60)

The course of the reaction of the [N1R2L2] or [NiX(R)L2] complexes with further ligand molecules depends upon the nature of the ligand and the group X. That with a third ligand molecule can proceed by addition (equations 113,114)8,18,161,328,334 o r (particularly where X is chlorate) with formation of ionic species (equations 115-117), 18 ' 53 ' 56 ' 1 ">l "M60,251252,255,260,308 a n d i n s o m e cases ligand exchange has been observed (equations 118,119). 16,53,252,283,394 j n e kinetics of the reaction shown in equation (119) indicate that it proceeds through an S^2 mechanism, presumably involving the stepwise coordination and decomplexation of the bidentate ligands.394 Phosphorus ligand exchange has been studied, with the help of 31 P NMR spectroscopy, for a series of [NiX(Ar)L 2 ] complexes and it has been suggested that steric factors are more important than electronic factors in determining the position of the equilibrium.150'271 [Ni(C=CPh)2(PEt2Ph)2]

+

PEt2Ph

—*-

[Ni(C=CPh)2(PEt2Ph)3]

(113)

Nickel Hydride, Alky I and Aryl Complexes [NiEt2(bipy)]

+

CH 2 =CHCN

[NiOCOCl3(C6F5)(PPh3)2] [NiCl(Me)(PMe3)2]

+

+

[Ni(C6F5)2(/?-dioxane)2] [NiMe2(bipy)]

+

PEt3

2CH 2 =PMe 3

[NiI(Me)(PMe3)2] +

—•

73

[NiEt2(bipy)(CH2=CHCN)] [NiC6F5(PEt3)(PPh3)2]+ClO4-

(115)

[NiMe(PMe3)2(CH2=PMe3)2]+Cl-

(116)

—*

—•

+

2 PMe3

2 NH 3

-+

[Ni(C6F5)2(NH3)2]

—*

[NiMe2(PPh2C3H6PPh2)]

PPh2C3H6PPh2

(114)

—*

[NiMe(PMe3)4]+I+

(117)

2p-dioxane +

bipy

(118) (119)

The methylation of a cyano group by reaction with methyl fluorosulphonate has been reported. The product is a cationic isocyanide complex (equation 120), 274 which in turn can be converted into a carbene complex by reaction with amines or alcohols (equations 121, 122). 40274 Similar behaviour has been reported for nitrile complexes (equation 123). 160 [NiCN(C 6 Cl 5 )(PMe 2 Ph) 2 ]

+

MeSO 3 F

[NiC 6 Cl 5 (CNMe)(PMe 2 Ph) 2 ]+PF 6 -

[NiC 6 Cl 5 (CNMe)(PMe 2 Ph) 2 ] + SO 3 F-

(120)

[NiC 6 Cl 5 jC(OMe)=NMe|(PMe 2 Ph) 2 ] + PF 6 -

(121)

—

^IOH*

HNBu* I F2

F2

(Bu'NCfeNi

/CvCF I 2

V

CF

Me 2 N-C +

Me2NH

—+

Ni

2

Bu'Nc' V

F2 [NiC 6 Cl 5 (NCMe)(PMe 2 Ph) 2 ] + ClO 4 -

Cs. T

PhMe2P. ^ § ^

(+)

2

(122)

CF2

F2 .NH=C(Me)OMe

X Ni C l s Q ^ N PMe 2 Ph

C1O4" (123)

Treatment of [NiBr(R)(PMe 2 Ph) 2 ] (R = C 6 C1 5 , CC1 2 =CC1) with TV-bromosuccinimide results in bromination of the nickel to give the paramagnetic species [NiBr 2 (R)(PMe 2 PH)2]. 272 A similar reaction involving [NiR 2 L 2 ] complexes leads instead to bromination of the nickel-bonded organic group (equations 124, 125). 273 Treatment of [Ni{C=CCH(OH)Me} 2 (PBu 3 ) 2 ] with MnO 2 causes oxidation of the secondary alcohol and [Ni(C=CC(O)Mej 2 (PBu 3 ) 2 ] is formed. 256 OMe

Br

/Q>-NiC2Cl3(PMe2Ph)2

222*

OMe

OMe

^N—NiC 2 Cl 3 (PMe 2 Ph) 2 Br

HC=C—NiC6Cl5(PMe2Ph)2

^ ^

(124)

OMe

BrC=C—NiC 6 Cl 5 (PMe 2 Ph) 2

(125)

(//) Reactions in which new Ni—C bonds are generated Most of the reactions in this class involve insertion. Many nickel alkyl or aryl complexes react with CO, but only in a limited number of cases have nickel acyl or aroyl complexes been isolated (equations 126-129). 10 ' 122 ' 139 ' 144 ' 153 ' 278 ' 302 ' 309 ' 385 ' 405 ' 421 ' 425 Methylation of the aryl group in (61) causes its conversion into a carbene ligand (equation 129). 302 Me3SU.88 [NiCl(CH 2 SiMe 3 )(PMe 3 ) 2 ]

+

CO

—••

^e3

^CH2

f

1-20^

89.9° I 91 5°

1 50\ I 2199 C-^Ni^Cl Me 3

(126)

74

Nickel Hydride, Alkyl and Aryl Complexes Me |1.57

[NiCl(Me)(PMe 3 )2]

+

CO

—^

M e 3 P ^ 9 . i y C % l 2o 2.220N yl. 8 4 O

1

2.265/

(127)

N2.194

Cl<9I5O>PMe3

[NiMe(PPh 2 C 2 H 4 ) 3 N] + BPh4-

+

CO

/ P h 2 P 231 / ^ ^ Ni(^PPh2

-^

(128)

11.97 1.36^0.44

Ox [Ni(C 6 H 4 Me-/7)(C 6 Cl 5 )(PMe 2 Ph) 2 ]

+

CO

—•

N

Me

[Ni(COC 6 H 4 Me-p)(C 6 Cl 5 )(PMe 2 Ph) 2 ] (61)

[Ni(C 6 Cl 5 ){C(OMe)C 6 H 4 Me-/ ? KPMe 2 Ph) 2 ] + ClO 4 -

• l ' ^ ^

(129)

Insertion of butyne has been observed in the reaction with the phenylnickel complex (62). The cis arrangement of the methyl groups in the product is indicated by the formation of cis-d\methylcinnamate on treatment with CO in methanol (equation 130).314 Related to this is the reaction of RC=CCH=CH 2 with [NiX(Ph)(PPh3)2] to give, after hydrolysis, PhCR=CHCH=CH 2 , 3 4 6 and that of benzyne (generated in situ by thermal decomposition of benzenediazonium-2-carboxylate) with [NiC=CPh(C2Cl3)(PEt3)2], from which [NiC6H4-oOE=CPh(C2Cl3)(PEt3)2] has been isolated.332 [NiBr(Ph)(PPh3)2]

+

MeC=CMe

(62) Me

Br

Me

PPh3

MeO2C

Ph

The oxidative addition of organic halides to tetrakis(isocyanide)nickel complexes is also accompanied by insertion of eliminated isocyanide molecules into the Ni—C primary bond and iminoacyl nickel complexes result (equation 131 ).17 The cyclic nickel acyl complexes formed by reacting [NiEt2(bipy)] with phthalic or tartaric anhydride undergo thermal CO elimination with formation of a Ni—C bond (equation 132).416

fi' [NKCNR'k]

+

RX

- ^ ^

[NiX(R)(CNR')3]

E2:!£

*

R'NCN / . C ^ N R ' Ni I X N* N R

(131)

R'

(bipy)Ni

)

o-i

—•

(bipy)Ni

N

[

o\

+

CO

(132)

Nickel Hydride, Alky I and Aryl Complexes

75

(///) Reactions in which the alky I or aryl group is displaced Three of the reactions discussed in this Section are frequently used to determine the nature of the organic group bonded to the nickel, viz. reductive elimination instigated by phosphines, carbon monoxide or alkenes, protonolysis and hydrogenation. We shall, however, first discuss thermolysis. The thermal decomposition of the [NiR 2 L 2 ] and [NiX(R)L 2 ] complexes often produces a mixture of products arising from reductive coupling, /3-hydrogen transfer and homolytic cleavage (equations 133-135). 17,18,35,77,171,280,306,315,334,345,379,394 If ^-hydrogen transfer is hindered by suitable substitution (e.g. Ni neopentyl), then products may be detected which presumably arise from a- or 7-hydrogen transfer (see, for example, ref. 335).

[NiMe2(PMe3)2] [Ni(CH2CH2Me)2(bipy)]

—

—•

C2H6

MeCH=CH 2

2[NiBr(CH=CHPh)(PPh3)2]

—^

+ +

[Ni(PMe3)2] MeCH2Me

PhCH=CHCH=CHPh

(133) +

+

"[Ni(bipy)]"

(134)

2[NiBr(PPh3)2]

(135)

The kinetics of the reductive elimination of ArMe from [NiMe(Ar)(PEt 3 ) 2 ] have been investigated and it could be shown that the rate of decomposition is first order and that the product is formed in an intramolecular manner. 315 ' 345 Whether the reaction proceeds through a trans square-planar complex, a cis square-planar complex or a tetrahedral complex, or whether alternatively ligand dissociation occurs to give a trigonal complex, has not been decided; no direct evidence has, however, been obtained for anything other than the normal trans square-planar geometry. A theoretical treatment of reductive elimination has been published which, however, favours a cis square-planar geometry for the active intermediate. 340 ' 341 The thermal decomposition of nickel acyl complexes can proceed with initial decarbonylation (equation 136). 302 Related to this reaction is that of tetrakis-ligand nickel complexes with acyl halides (RCOX) from which RCOR compounds have been isolated81 and, presumably, that of phenyl carboxylate with cyclooctadiene nickel phosphine complexes in which phenol is formed (equation 137). 338 [Ni(COC6H4Me-/?)(C6Cl5)(PMe2Ph)2]

—-•

C6CI5C6H4Me-p

+

[Ni(CO)(PMe2Ph)2]

(136)

[Ni(CO)(PPh3)3]

(137)

-cod

[Ni(PPh3)2(cod)]

+ EtCO2Ph - — • [NiOPh(COEt)(PPh3)2] ^

C2H4 + PhOH

+

Thermal decomposition products which result from reaction between the ligand and the nickel-bonded organic group have been occasionally reported (equation 138), 64 ' 267 while the transfer of a phenyl group from phosphorus to nickel is suggested to be involved in the thermal generation of the phosphide (63) (equation 139).136 Attempts to prepare this intermediate directly by reacting [NiBr(Ph)(PEt 3 ) 2 ] with LiPPh 2 led to the formation of (63) and [Ni(PEt 3 ) 2 (PPh 3 ) 2 ]. [NiCI(Ph){P(C 6 H 4 Me-p) 3 ! 2 ]

—> PhPh(0.72), /7-MeC 6 H 4 Ph(1.3), /?-MeC 6 H 4 C 6 H 4 Me-/? (1)

(138)

Ph 2 p 2[Ni(PEt 3 ) 2 (PPh 3 )]

—••

2[L 2 NiPh(PPh 2 )]

" C|2H|0 >

(Et3P)2Ni^^Ni(PEt3)2 Ph 2 (63)

(139)

76

Nickel Hydride, Alkyl and Aryl Complexes

The anodic oxidation of [NiR(Ar)(PEt3)?] complexes has been studied and both concerted and radical pathways are suggested to account for the mixture of products.281 Cathodic reduction of [NiBr(Ph)(PPri3)2], in the presence of free phosphine, to give diphenyl has also been reported. 346 The product of the thermal decomposition of nickelacyclopentane derivatives has been shown to be dependent upon the number of donor ligands associated with the metal (e.g. Scheme 4). Monophosphine derivatives undergo ^-hydrogen transfer to give 1-butene, bis-phosphine derivatives undergo reductive elimination to give cyclobutane, while tris-phosphine derivatives undergo /3-carbon cleavage and eliminate ethylene.87'263'264'289"291'310 Experiments with deuterium-labelled complexes indicate that this last process involves the intermediate formation of a bis(ethylene)nickel complex. Related behaviour has been observed in the thermolysis of bis(triphenylphosphine)nickelacyclohexane,264 the (bipy)nickelatricycloheptane derivative (49) 257 - 307 and the (bipy)nickelapentacyclopentadecadiene derivative (47), 131 which all eliminate cyclic products. The (bipy)nickelacyclopentane derivative (46) 325 and the nickelahydrindane derivative (50) 292 decompose principally by /3-hydrogen transfer. An orbital symmetry justification for the observed behaviour of the nickelacyclopentane derivatives has been published.259 The photochemical decomposition of a few nickelacyclic systems has been studied: considerable C—C bond cleavage occurs but no mechanistic conclusions have been drawn. 264 ' 290 ' 292 (Ph3P)NiJ

^

(Ph3P)2NiJ

I

^=*

(Ph3P)3Ni/J

I

\

1

Q

2CH2=CH2

Scheme 4

The tris(triphenylphosphine)nickelacyclohexane complex (64) also decomposes to give mainly ethylene. Here the initial reaction is suggested to be a-carbon cleavage to give a carbene-substituted nickelacyclopentane intermediate (equation 140), which reacts further as indicated in Scheme 4. 264 CH2

O

-PPU - ^ ^

I

(Ph 3 P) 2 Ni—v I \

^

2CH 2 =CH 2

+

[CH2:]

(140)

(64)

An unusual example of reductive coupling is the thermal conversion of the nickelacyclopentadiene derivative (65) into the corresponding 7?-cyclobutadiene complex (equation 141) 339 (see also ref. 395). This reaction is reminiscent of that observed on treating [NiCl(CH=CH2)(PCy2C2H4PCy2)] with vinyllithium, from which a zerovalent nickel-butadiene complex has been isolated.343

72A> rv Cy2

' ph (65)

^2phwph Cv Cy2

ph

ph

The course of the reaction of the ligand-stabilized nickel alkyl and aryl complexes with excess ligand is closely related to the thermal decomposition discussed above. Tertiary phosphines, electron-deficient alkenes or carbon monoxide are commonly used; however, a few examples in-

Nickel Hydride, Alkyl and Aryl Complexes

11

volving dioxygen are known. 290 ' 307 ' 315 The [NiR2Lw] complexes normally react by reductive elimination of R—R, 18,72,257,263,290,292,302,306,313,325,333,334,380,394 ( e q u a tions 142-144). The activation energy for the elimination of R—R from [NiR2(bipy)] complexes has been shown to decrease upon coordination of an electron-deficient alkene. 334 For example, the value of ca. 284 kJ mol" 1 for the thermal decomposition of [NiEt2(bipy)] is reduced in the presence of acrolein to ca. 67 kJ mol" 1 . A MO justification for this activation of the Ni—C bond has been given.324 Phosphines have a similar effect and the second-order kinetics observed indicate that here also the rate determining step is the further reaction of a five-coordinate adduct, [NiR2(bipy)(PR 3 )]. 3 2 3 ' 3 9 4 [NiMe2(PMe3)3]

+

PPh3

(bipy)Ni

"*

+

[Ni(PMe3)3(PPh3)]

X

VL H

—•*- C2H6

+

f

[NiC6Cl5(C6H4Me-/?)(PMe2Ph)2]

A

O -+

+

(142)

X Q X

+ (bipy)Ni-(fo

(143)

C12C=CC12

—+ Cl5C6C6H4Me-/?

+

[NiCl(C2Cl3XPMe2Ph)2] (144)

The [NiX(R)L2] complexes show a more varied behaviour. In some cases reductive elimination of RX is observed (equation 145); 135,286,287 m others, homolytic cleavage occurs to give nickel(I) species (equation 146), 77 ' 306 while occasionally arylphosphonium salt formation is the main reaction (equation 147). 318 The first and the last reactions can be carried out catalytically. The mechanism of the reductive elimination of PhCN from [NiCN(Ph)L 2 ] upon treatment with a second ligand ( I / ) has been studied in detail and shown to be dependent upon the nature of the ligand molecules involved: where L = PPI13 and \J - PEt3, a binuclear associative mechanism involving the five-coordinate intermediate [NiCN(Ph)(PEt3)(PPh3)2] is implicated, whereas when L = PEt3 and 1/ = P(OEt)3, reductive elimination through a four-coordinate intermediate [NiCN(Ph)(PEt 3 )P(OEt) 3 ] is believed to be the main reaction. 135286 ' 287 [NiCN(PhXPPh3)2] 2[NiCl(CH2Ph)(PPh3)2] [NiCl(Ar)(PPh3)2]

4+

+

2PPh3

2PPh3 2PPh3

—•

[Ni(PPh3)4]

+

—* PhCH2CH2Ph —•

ArPPh3+Cl-

+ +

PhCN 2[NiCl(PPh3)3] [Ni(PPh3)3]

(145) (146) (147)

The reaction of nickel alkyl and aryl complexes with CO is complicated by the ease with which insertion into the Ni—C bond occurs. We have mentioned in a preceding Section (p. 61) reactions which lead to stable nickel acyl or aroyl complexes. In one case the further reaction of a nickel aroyl complex with CO has been studied and the anticipated product of reductive elimination was isolated (equation 148).302 The product of the reaction of the [NiR 2 L 2 ] complexes with CO depends upon the reaction conditions, the geometry of the molecule and the reactivity of the Ni—C bonds involved. Three types of reaction are observed 254 ' 266 ' 290 ' 292 ' 294 ' 3 ' 3339 [in addition to elimination of R—R (equation 149)]: monoinsertion followed by reductive elimination (equation 150), diinsertion followed by reductive elimination (equation 151) and a combination of monoinsertion and alkene elimination to give an aldehyde (equation 152).

[Ni(COC6H4Me-/?XC6Cl5)(PMe2Ph)2]

+ 2CO —•

[NiEt2(bipy)]

+

CO —

C6Cl5COC6H4Me-/7

+

[Ni(CO)2(PMe2Ph)2] (148)

[NiCOEt(Et)(bipy)J - ^

Et2CO

+

[Ni(CO)2(bipy)J (149)

78

Nickel Hydride, A Iky I and Aryl

Complexes

H

[" J^\i(PPh 3 ) 2 [NiMe 2 (bipy)]

+

2CO

+ 3CO -+

TjO^

+

[Ni(co)2(PPh3)2]

(150)

—*> [Ni(COMe)2(bipy)] 2£

^

Ph 2 Pv [ NiEt 2

0

MeCOCOMe

+

[Ni(CO)2(bipy)] (151)

Ph 2 J +

CO

—*

V

COEt-

I

Ni

S'

Ph2

Et

Ph2 1=

^

EtCHO

+

CH 2 =CH 2

+

Ph2 P^ T \i(CO)2 p' Ph2

(152)

Carbonylation of the [NiX(R)L 2 ] complexes can lead to formation of RCOX 81 > 138 ' 425 which, in alcohol, reacts further to give an ester (equations 153,154). 35 ' 314 ' 405 The kinetics of the reaction of a series of [MX(Ar)L 2 ] complexes of Ni, Pd and Pt with CO have been investigated: 138 the data for nickel are limited but are suggested to indicate that the mechanism of carbonylation is similar to that observed for the more stable platinum complexes and to involve the initial formation of a five-coordinate [MX(Ar)(CO)L 2 ] intermediate. The possibility that ionic species could play a role is suggested by the mode of reaction of [NiOCOCl 3 (C 6 Cl5)(PMe 2 Ph)2] with CO, from which the cationic complex [NiC 6 Cl5(CO)(PMe 2 Ph)2] + ClO4" has been isolated. 255 [NiCl(Ph)(PPh3)2]

+

3CO

—*

PhCOCl

+

[Ni(CO)2(PPh3)2]

(153)

— H Rr

[NiBr(CH=CHPh)(PEt 3 ) 2 ]

+

3CO

+

MeOH >PhCH=CHCO 2 Me

+

[Ni(CO)2(PEt3)2] (154)

Insertion of alkenes into the Ni—C bond has also been observed (equation 155). 17 Related to this is the isolation of insertion products (RCH 2 CH 2 Y) from the reaction of the unstable nickel alkyl species formed by reducing a nickel-tetraazacyclotetradecane complex in the presence of an alkyl bromide (RBr) and an alkene ( C H 2 = C H Y ) , 293 [NiBr(Ph)(PPh3)2]

+

PbCH=CH 2

—••

[NiBr(CHPhCH2PhXPPh3)2] PhCH=CHPh

+

—

[NiBr(H)(PPh3)2] (155)

It is convenient to mention here a process involving insertion of SO 2 . In general, transition metal alkyl complexes react to give products containing the S-sulphinato group; however, the cationic complex [bis(diphenylphosphinoethyl)phenylphosphine](methyl)nickel gives instead an 0-sulphinato complex whose structure has been confirmed by X-ray methods (equation 156). 269 Ph \ 2.199 I 2.214/ +

[NiMe(PPh 2 C 2 H 4 ) 2 PPh] BPh 4 -

+

SO2

—*

Ph2P

794J98 1 7° PPh2

Bph

4~

< 156 )

MeX?7 Protonolysis is one of the standard methods for determining the nature of the Ni—C

Nickel Hydride, Alky I and Aryl Complexes

79

bond. The reaction is normally carried out with inorganic acids (equations 1 5 8 ) , 3 5 ' 5 ' ^2,90,92,102,137,171,241,251,257,260,264,290,292,294,305,419

157,

18 257

hols, -

but

in

s o m e

cases a

]

c o

_

malonic acid esters, 257 ' 275 or a silane58 have been used/equations 159-161).

H Ph-C. %

C—NiBr(PEt 3 ) 2 I H

+

D 2 SO 4

{^jr N Ni(PPh 3 )2

(bipy)Ni

[NiEt2(bipy)] [NiMe2(bipy)]

H

^

+

+

+

+

+

2MeOH —+

\y v j

—*

[NiBr(DSO4)(PEt3)2]

+

2HC1 —* (^X

2(EtCO2)2CH2

3HSiCl3

H D ^C=C Ph ^H

—•

+

2C2H6

+

(157)

[NiC12(PPh3)2]

(158)

[Ni(OMe)2(bipy)]

(159)

[Ni{CH(CO2Et)2(2(bipy)]

(160)

—• CH4

+

H2

+

MeSiCl3 +

[Ni(SiCl3)2(bipy)] (161)

Hydrogenation has been less frequently implemented266 (equation 162). Reactions involving nickel complexes are often autocatalytic or can be carried out in the presence of catalytic amounts of Raney nickel or bis(cyclooctadiene)nickel. The isolation of polydeuterated ethane in addition to C2H5D from the reaction of [NiEt 2 (bipy)] with D 2 indicates that a /3-H(D)-elimination-addition process occurs parallel to hydrogenation.163

Cy2 I

\ i

1

+

4H 2

—*• Me2CHCHMe2

+

"[NiH2(PCy2C2H4PCy2)]"

(162)

Cy2 The Ni—C bond can also be cleaved by reaction with nitroso compounds,417 halogen (equations 163, 164),82-83-25!,264,290,292,305 m e r c u r y chloride (equation 165),102'306-414 or with halides whereby reductive elimination 63 ' 109 ' 301 ' 315 as well as coupling with the organic halide 18 ' 90 ' 158 ' 257 ' 304 ' 339 ' 374 can occur (equations 166-168). Reactions of the last type can be carried out without isolation of the intermediate nickel alkyl complex 153 ' 336 and may have synthetic interest. The reaction between aryl halides and [NiX(Ar)(PEt 3 ) 2 ] has been studied in detail and leads to formation of arylphosphonium salts (equation 169). 118 - 345 ' 374 The implications of this observation for the catalytic synthesis of diaryls and of phosphonium salts are discussed in Chapter 56.5.

[NiCl(2,4,6-Cl3C6H2)(PPh3)2] (Ph3P)2Ni

J

[NiNO(Ph)(PPh3)2]

+ + +

Cl2 2Br2

—* —*

HgCl2

—•

1,2,3,5-C14C6H2 Br(CH2)4Br PhHgCl

+ +

+

[NiCl2(PPh3)2]

[NiBr2(PPh3)2] [NiCl(NO)(PPh3)2]

(163) (164) (165)

80

Nickel Hydride, Alkyl and Aryl Complexes

/^SiMe2 (Ph3P)2Ni I V--SiMe 2

+

1-naphthylBr —* w , J T j l M C 2

^ j ) — NiCl(PEt3)2

—*

[NiBr(naphthyl)(PPh3)2] (166)

OTV-NiCKPEt3)2 ^ ^

u

V ,X—H +

CH2Br2

+

O C /

H

(bipy)Ni

+

—•

X

[NiC1(C2C13XPEt3)2] (167)

I" /^^H

<

+

[NiBr2(bipy)]

(168)

(ArPEt3)2+NiBr42-

(169)

X

[NiBr(Ar)(PEt3)2]

+

3ArBr

—•

Ar— Ar

+

Unusual behaviour is observed on treating the nickel imide (66) with phenyl bromide; cleavage of the Ni—N bond occurs to give high yields of iV-alkyl- or -aryl-imides (equation 170). 298 O

Kjf

O

NNiMe(PEt3)2

+

PhBr

^+

( N 3 CNPh

O

(95%)

(170)

O (66)

Ni—C bond cleavage is also observed on reacting nickel alkyls with aluminium alkyls. The reaction involving [NiMe 2 (bipy)] has been investigated in detail and the unstable red complex formed with trimethylaluminium is suggested to have structure (67) (equation 171). 1,22,95,164 This complex decomposes above — 60 °C, liberating methane and ethane. A complex presumably related has been isolated from the reaction of [NiMe(C6H 4 -oMe)(PEt3) 2 ] with methyllithium315 (see also ref. 257). Me [NiMe 2 (bipy)]

+

AlMe 3

M

—+> (bipy)Ni

AlMe 2

(171)

Me (67)

37.4.33.3

Physical properties and bonding

The 2/?3/2 binding energies for a number of [NiR^I^] and [NiX(R)L2] complexes have been measured by X-ray photoelectron spectroscopy.42'156'253'288'424 A reasonable correlation is obtained between the Ni 2/?3/2 binding energies and the calculated charge parameter <7Ni (the sum of the partial ionic characters of the four bonds to nickel) for a series of aryl, vinyl and acyl complexes, which is interpreted as indicating that ^-interaction between the nickel and the organic group is of only minor importance in these systems (see, however, refs. 67, 79). Anomalous values are, however, obtained for [NiC=CPh(3,5-Me 2 C 6 H4)(PEt3)2] and [Ni(C=CPh) 2 (PEt 3 ) 2 ], suggesting that in these complexes the Ni—C bond has substantial 7r-character. This interpretation is supported by a far-IR study of the M—C stretching frequencies for [Ni(C=CR) 2 L 2 ] complexes.34 A number of examples are known in which anomalously high downfield shifts are observed in the ] H NMR spectra of nickel aryl complexes as the result of the juxtaposition of a proton and

Nickel Hydride, Alky I and Aryl Complexes

81

the nickel atom. Examples in which this effect is particularly marked include (68) 49 and (69) (L = PEt3) 7 ' 331 (the relevant chemical shifts are shown in brackets). H (54 )H

° )c=c /Me

(863)

cl

,•

7Ni^H

L I

^_Nt^

^\

HCH27) H(8.02)

(68)

(69)

37.4.3.4 *73-Allylnickel Alkyl and Aryl Complexes A great many nickel alkyl and aryl complexes have been isolated in which the nickel-carbon bond is stabilized by an r/3-allyl group and, frequently, a donor ligand. Most of the known complexes are discussed and tabulated in ref. 1, pp. 208-215 and pp. 376-392, while recent examples are shown in Table 8 (p. 85). The ligand-free complexes [{NiR(i73-allyl)j2] have been prepared by reacting the appropriate nickel halide with a Grignard reagent (equation 172). 208 ' 246 ' 249 - 365 The crystal structure of the 773-l,3-Me2C3H3 complex (70) confirms the dimeric nature of the molecule and suggests the presence of both a nickel-nickel bond and bridging methyl groups. 242 A MO description of the bonding in the unsubstituted complex [{NiMe(r73-C3H5)}2] has also been published.242 Complex (70) has been shown by 13C NMR spectroscopy to be in equilibrium with a second isomer in which one of the allylic methyl groups adopts an anti arrangement. 245

2.05 V ^ ^ r - 2 - 0 4 6 3

[{NiBr(77 -l,3-Me2C3H3)!2]

+

2MeMgBr

"

2MgBr2

>

L

^*/Ni - / 2029

237,

'

Ni 1.333/ 'i^^p^

(172)

2.023-

(70)

The 773-allylnickel methyl complexes disproportionate on warming to - 7 0 °C (equation 173), 208 ' 246 ' 365 while the ethyl complex decomposes completely at - 1 1 0 °C; experiments with deuterium-labelled ethyl groups indicates the intermediate formation of a nickel hydride as the result of /^-hydrogen transfer (equation 174).164'175 The introduction of methyl groups into ?73-allyl systems is accompanied by an increase in stability: [{NiMe(?73-C3H5}2] decomposes at —70 °C in toluene, while [{NiMe(773-l,3-Me2C3H3)}2] is stable to +10 °C. [|NiMe(773-C3H5)J2] |[|NiCH2CD3(7;3-C3H5)J2]

~>

—•

[Ni(773-C3H5)2]

+

(173)

"[NiMe 2 r

[^-*\CH2] CD2 —••

CH 2 =CD 2

+

C3H5D

+

Ni

(174)

Reaction with methylmagnesium chloride or trimethylaluminium leads to systems in which methyl groups are bridging two different metals, e.g. (71) (equation 175). NMR investigations indicate that at elevated temperatures scrambling of the methyl groups occurs. 249 ' 365 The ?73-allylnickel alkyl complexes readily form adducts with donor ligands (equation 176).246

82

Nickel Hydride, Alkyl and Aryl Complexes

Complexes containing two donor ligand molecules have also been isolated, e.g. [NiMe(PPli3)2(C3H5)]; whether these contain an r\x- or r/3-allyl group remains, however, to be decided. 208 The enthalpy of the reaction between [jNiMe(^3-l,3-Me2C3H3)}2] and a variety of tertiary phosphines has been determined in solution by differential thermal analysis and the results correlated with the steric and electronic properties of the ligands; both are found to be of comparable importance.232 Ligand-stabilized complexes of this type are more conveniently prepared by reacting the appropriate nickel halide with alkyl or allyl Grignard reagents (equations 177, 178)

.112,243

[{NiMe(7/3-l,3-Me2C3H3)j2]

+

2AlMe3

—•

2tf-Ni >

A<

(175)

2[NiMe(PPh3)(r73-C3H5)]

(176)

Me (171)

3

[{NiMe(77 -C3H5)!2] [NiBr(PCy3)(r73-l-MeC3H4)] [NiCl(C 6 Cl 5 )(PMe 2 Ph) 2 ]

+

+ +

2PPh 3

— ~MgC'Br>

MeMgCl

CH 2 =CHCH 2 MgCl

[NiMe(PCy 3 )(r? 3 -l-MeC 3 H 4 )]

"M^C'2>

[NiC6Cl5(PMe2Ph)(773-C3H5)]

(177) (178)

A number of individual reactions leading to complexes of this type have been reported and are discussed below. 1,3-Dienes react with zerovalent nickel alkene complexes in the presence of basic phosphines to give octadienediyl nickel complexes which are believed to be involved as intermediates in the nickel-catalyzed oligomerization of dienes (equation 179) and are discussed further in Chapter 37.6. Related ionic complexes have been isolated from the reaction of the bis(ethylene)nickel phosphide species (72) with butadiene (equation 180), 376 ' 413 and from the reaction of divinylcyclobutane with [Ni(cdt)] and phenyllithium (equation 181). 375 [NiPCy3(cdt)]

+

2 ^ ^ ^

—+

Ni

J

+

cdt

(179)

Cy 3 P / [iNi(CH2=CH2)2)2PCy2]Li(THF)4

+

4 ^ ^ ^

(72)

~* C X /NO [ U ( T H F ) 4 ] + °8o) Cy2 [Ni(cdt)] +

LiPh

+

[X^

m

^T*'

'*^^)[Li(TMEDA)2]+ Ph^ ^^^

(181)

The reaction of bis(r73-allyl)nickel complexes having anti substituents with /-phosphines leads, in some cases, to r)3 ++ r?1 isomerization of one allyl group: NMR evidence indicates that in (73) rapid allyl exchange is occurring even at - 9 5 °C (equation 182).244 The intermediate formation of T71-allylnickel complexes is also believed to be involved in the syn ** anti isomerization observed upon treatment of bis(r;3-allyl)nickel complexes with donor ligands.244

I Nil

+

PMe3 —

/NivU>^

^

Y1!

°82)

(73)

One case has been reported in which insertion of an alkyne molecule into a nickel-allyl bond has occurred to give a nickel alkenyl species (74) (equation 183).32 What may well be a related product has been isolated from the reaction of bis(cyclooctadiene)nickel, butadiene and the Schiff

Nickel Hydride, A Iky I and Aryl Complexes

83

base/?-RC 6 H 4 CH=NPh, 3 7 7 and in the reaction of the tris-isoprene species [Ni(?73,?73-Ci5H24)] with alkynes. 407

Ph 3 P-fN?^[]

+

EtCO2C=CCO2Et

—^

EtO2C

Ni

\

(183)

EtO2C (74) The crystal structure of four [NiR(L)(?73-allyl)] complexes have been published: [NiPCy 3 (77 1 ^ 3 -2,6-Me 2 C 8 H, 0 )] (75), 247 [NiPCy 3 (V,*7 3 -4,5-Me 2 C 8 H 10 )], 248 [NiMe( P P r ^ P h X ^ - U - M e ^ H ^ ] (76) 26 ' 365 and [NiMefP(menthyl)2Me)(7?M,3-Me2C3H3)] (77). 26 The main interest in these structures involves the ?73-allyl group and discussion is therefore reserved for Chapter 37.6; suffice it to note here that the nickel atom in all four complexes is in a square planar environment with Ni—C bond distances of 1.978(3) (75), 1.99(1) (76) and 1.975(4) A (77). The [NiR(L)(773-allyl)] complexes are chiral and exist as enantiomers (78). These have been detected in solution by NMR spectroscopy for complexes containing the optically active ligands NH 2 CH(Ph)Me, P(menthyl) 2 Me or the prochiral ligand H 2 C=PPr' 3 . The X-ray structural determination for [NiMefP(menthyl)2Me)(773-l,3-Me2C3H3)] mentioned above shows* the molecule to have an absolute configuration R.26>249 i

(78)

The [NiR(L)(773-allyl)] complexes are in general more stable than the ligand-free species. The ethyl compounds, however, eliminate ethylene at low temperature to give a nickel hydride (equation 184); see ref. 1, p. 147. Protonation occurs in a stepwise manner and can be used to prepare [NiX(L)(773-allyl)] complexes (equation 185). 208 Complexes in which a ligand having active hydrogen atoms is associated with the nickel undergo internal protonation. For example, the secondary amine complex (79) reacts to give a dimeric amide (equation 186). 249 This reaction can be regarded as a model for the linear dimerization of 1,3-dienes in the presence of amines or alcohols. [NiCH2CH3(PPh3)073-C3H5)] [NiMe(L)(7;3-C3H5)]

+

HX

[NiH(PPh3)0?3-C3H5)]

+

CH 2 =CH 2

(184)

^ ^

\ l(-Ni

/

—

[NiX(L)(j/3-C3H5)]

^

\ (f-NiNR 2 ) 2

+

Me —

X

NHR2

[NiX2L]

2CH4

+

C3H6 (185)

(186)

J

(79)

* The molecule is treated as having pseudo-tetrahedral geometry: three positions are occupied by the central C atom of the allyl group (meso-C), the phosphorus atom and the methyl group. The fourth position is empty. From this follows the R sequence PR3 > allyl > methyl > (0). 26249

84

Nickel Hydride, Alky I and Aryl Complexes

Insertion into the Ni—C bond has been observed in reactions involving isocyanides, nitriles, carbon monoxide, phenyl isocyanate and SO2. The isocyanide and nitrile derivatives (80) and (81) rearrange to give imonoacyl and imide complexes, respectively (equations 187,188). 249 The insertion of CO2, SO 2 and PhNCO into V-allyl complexes has been reported. The products, e.g. the 773-allylnickel carboxylate and S-sulphinato complexes (82) and (83) (equations 189, 190), are discussed in Chapter 37.6.43'241 Reaction of [NiPCy3(771,T73-C8Hi2)] with CO 2 is accompanied by rearrangement of the Cg moiety to give a tetrameric nickelalactone whose structure has been deduced crystallographically (see equation 108, p. 71). 241 The four LNiOCOC 8 Hi 2 units are so arranged that a (NiOCO)4 ring is formed in which each nickel has a square planar coordination. \ CNR 2<£—Ni^ —

\ jf-NiC(Me)=NR!2

Me

)

(187)

>

(80) ) /NCR \ 2€—NL — • (£-NiN=C(Me)RJ2

Me

}

(188)

/

(81) [Ni(7?3-2-MeC3H4)2]

+

PMe 3

+ CO 2 [NiOCOC4H7(PMe3)(773-2-MeC3H4)] (189)

—•

(82)

Cy 3 P / \ _ / ^

Cy3PX

^S I O2 (83)

The triphenylphosphine ylide complex (84) undergoes an unusual Stevens-type of rearrangement to give a diphenylbenzylphosphine adduct (equation 191).249 Reactions of this type have also been observed with bis(cyclooctadiene)nickel: tetrakis(diphenylbenzyl)nickel results. 250 \

4^

Ni

XH 2 PPh 3

)

~^ V"

^

Me

>

Ni N

PPh2CH2Ph

(191)

Me

(84)

Reductive coupling of the 773-allyl and alkyl group under the influence of tertiary phosphines or CO (equations 192, 193) is of considerable interest as a model for what is believed to be the final step in many catalytic oligomerization reactions involving dienes, and is discussed further in Chapter 56.4. A characteristic of the [ N i L ^ ^ - C g ) ] complexes is that reaction with excess phosphine leads to cleavage of the chain and liberation of the diene. In some cases the intermediate zerovalent nickel alkene complex can be isolated (equation 194). 248 [NiMe(L)(7/3-C3H5)] +

N j J

Ni Cy3P

/

I ^

+

+

3CO

PCy3

3L —*

—

—*• [NiL4] + t Ni (CO) 3 L]

^ ^ ^

(192)

M

(193)

+

|hNi(PCy 3 ) 2

+

^

^

(194)

Nickel Hydride, Alky I and Aryl Complexes Table 8

[{NiR(r/3-Allyl)}] and [NiR(L)(T/3-Allyl)] Complexes*

R

tf-Allyl

Ligand (L)

C 3 H 5 a (70) l-MeC3H4a 2-MeC3H4a l,3-Me2C3H3a cyclooctenyla l-MeC 3 H 4 a l,3-Me2C3H3a l,3-Me2C3H3a cyclopropyl C3H5a Me 2 C=CHCH 2 l,l-Me 2 C 3 H 3 Ph C3H5a mesityl C3H5a C6C15 C3H5 l-MeC 3 H 4 2-MeC3H4 7/l,r/3-C8Hi2-/)-RC6H4CH=NPh [NiPh(77l,773-C8H12)]Li(TMEDA)2 [{Ni(r/',773-C8H12)}2PCy2]Li(THF)4 Me

a

85

— — — — PCy3 PPr^Ph P(menthyl)2Me — PMe3 (73) — — PMe2Ph PMe2Ph PMe2Ph

Ref. 365 365 365 242, 245, 365 365 243 26 26 365 244 365 365 112 112 112 377 375 376,413

Earlier work is discussed and tabulated in ref. 1, pp. 208-215, 376-392.

37.4.3.5 ly-Cyclopentadienylnickel Alkyl and Aryl Complexes Although the parent complex [NiR^-CsHs)] has still to be isolated, a great many derivatives stabilized by donor ligands have been synthesized. Recent examples are listed in Tables 9 and 10 (pp. 91, 92); earlier work is discussed in ref. 1, pp. 215-234. The various preparative methods have been discussed in ref. 1 and we need only mention the most important here. Main group metal alkyls or aryls (generally an organomagnesium or organolithium complex) react with the appropriate nickel halide (equations 195, 196).i5,30,3i,22],224,226,23i,40i,42i jfe reaction of the ?7-cyclopentadienyl nickel carbonyl anion with organic halides has been less frequently used (equations 197, 198). 31 ' 227 ' 402 Dehydrohalogenation is a useful synthetic route to the nickel alkynyl complexes. The reaction is carried out in the presence of an amine and is catalyzed by copper salts (equation 199). 222 Insertion of isocyanides into the nickel-carbon bond leads to formation of iminoacyl derivatives (equation 200).225,234 xhis class of compound can also be formed by deprotonation of the cationic nickelcarbene complex (85) with sodium methoxide (equation 201);220 the reaction is reversible. Insertion is also observed in reactions involving RNCS 2 2 1 and sulphur dioxide235 (see Chapter 37.8). [NiCKPPhaXii-CsHs)]

+

MgCl(CHCH2CH2) ~MgC'2>

[NiI(PPh3)0?-Me5C5)] [NiCO^-CgHs)]-

+

+

LiMe

ClC(Ph)=NPh

[NiCCKTj-CsHs)][NiCl(PPh3)(77-C5H5)]

+

+

EtCOCl

HC^CH

+

+

[NiMe(PPh3)(j?-Me5C5)]

(196)

=^^

[NiC(Ph)=NPh(CO)(7/-C5H5)]

(197)

=^^

[NiCOEt(COX77-C5H5)]

(198)

[NiC=CH(PPh3X>7-C5H5)]

+

H2NEt2Cl

(199)

[NiC(Ph)=NC6H4Me-p(CNC6H4Me-/?X^C5H5)]

(200)

2/7-MeC6H4NC ^

[Ni=C(Ph)NHCy(CNCy)0;-C5H5)]+BF4-

^==^ nDr4

(85)

=^

Et2NH

^ [NiPh(PPh3)(^-C5H5)]

[NiCHCHzCHzCPPhsX^-CsHs)] (195)

[NiC(Ph)=NCy(CNCy)(»/-C5H5)]

(201)

86

Nickel Hydride, Alky I and Aryl Complexes

A rather unusual reaction is that of the iminium-nickel complex (86) with sodium cyclopentadienide (equation 202); oxidative addition of the iminium ion to the nickel has occurred.371 [NiCl(PPh3)0?2-CH2=NMe2)]

+

NaC5H5

^^+

[NiCH2NMe2(PPh3)(>7-C5H5)]

(202)

(86) The structure of three simple [NiR(PPh3)(7/-C5H5)] complexes (where R is Ph, C 6 F 5 and CF 3 ) have been determined. 238 The geometry around the nickel is similar in all cases and that for the phenyl derivative (87) is shown here. Relevant bond distances for the other complexes are Ni—C = 1.91(1), Ni—P = 2.145(4), where R is C 6 F 5 ; Ni—C = 1.95(3), Ni—P = 2.15(1) A, where R is CF 3 .

|l.78

Ni 1.90/

J^

93A

\2.I38

PPh3

(87) A few cases have been reported 68 ' 88 ' 239 in which the 'H NMR spectra of [NiR(L)(77-C5H5)] complexes are temperature dependent, e.g. where R = CH 2 SiMe 3 , CH 2 Ph. Restricted rotation about either the Ni—C or the P—C bond has been considered as the origin of these effects. In the case of triphenylphosphine complexes the latter seems more tenable and would lead to a barrier between enantiomeric conformations. The 31 P chemical shifts and the electronic spectra for a series of [NiR(PPh3)(77-C5H5)] complexes have been reported 233 and an unsuccessful attempt made to correlate the chemical shift against the high energy d-d transition. The controlled thermal decomposition of the nickel alkyl complexes has been studied (equation 203). 106 /3-Hydrogen transfer is the preferred pathway (the intermediate Ni—H could not, [NiCH2CH2Me(PPh3)0?-C5H5)]

—*

CH 2 =CHMe

+

"[NiH(PPh3)(i?-C5H5)r

(203)

however, be detected). Complexes in which /3-hydrogen atoms are absent are more stable and decompose by a unimolecular reaction which does not, however, involve free radicals. The observed stability series is: Buj ~ Bus < Pr < Bu - Et < Me < CH 2 Ph < CH 2 SiMe 3 Similar results have been obtained in the photolysis of [NiR(PPh3)(77-C5H5)] (where R = Me, Ar). 401 The reverse reaction, i.e. insertion of an alkene into the Ni—H bond, has been suggested to account for the formation of [NiBu(PPh3)(77-C5H5)] on treatment of [Ni(r73-C5H7)(?7-C5H5)] with ethylene in the presence of triphenylphosphine.406 Thermolysis of the but-3-enyl complex (88) leads to generation of a 7/3-l-methylallyl group. 30 Experiments with deuterium-labelled samples indicate that the reaction proceeds by a ^-hydrogen elimination-transfer mechanism. The photochemical rearrangement of the same complex is regioselective and proceeds principally by a 1,3-hydrogen shift, presumably involving an alkene complex (equation 204).

i

/

/Ni\ Ph3P

\

CH 2 CH 2 CH=CH 2

\

\ ^ / \h>

w

\

i

/

V'

IV^l

^ r

I

N»

/ /

"^i^\

(204)

Nickel Hydride, Alky I and Aryl Complexes

87

A number of interesting individual reactions which lead to 77-cyclopentadienylnickel alkyl or aryl complexes have also been reported. Spiroheptadiene compounds react with nickel tetracarbonyl to give a mixture of the bridged nickel alkyl and acyl complexes (89) and (90) (equation 205). 133 ' 134 ' 400 A related complex (91) is formed on reacting diphenylcyclopropenone with nickel tetracarbonyl and diphenylacetylene.28 The known reactivity of the 77-cyclopentadienylcobalt alkyne complex (92) with further alkyne has been used to prepare the unusual nickel-substituted cobalt r?4-cyclobutadiene complex (93) (equation 206).219 Migration of a phenyl group from boron or lead occurs if [Ni(PPh3)2(7?-C5H5)]+BPh4- or [NiPbPh3(PPh3)(T7-C5H5)] are heated (equation 207).19«236

[Ni(co)4] + / " " V r ^

—*

i

i +

i

zNi\/

^^N

/

(205)

zNi—i

(89)

(90)

Ph

(91) [NiC=CR 3 (PPh 3 X^C 5 H 5 )]

[CoPPh3(R1C=CR2X^-C5H5)]

+

(92)

It

R2NJO

R3

(206)

R1

NiPPh3(i7-C5H5) (93)

[NiPbPh3(PPh3Xi?-C5H5)]

—•

[NiPh(PPh3X^-C5H5)]

+

"[PbPh2]"

(207)

o-Arylnickel complexes are also produced in the reaction of diazobenzene with nickelocene (equation 208): complexation of a diazobenzene molecule probably causes isomerization of one of the cyclopentadienyl rings to the cr-form, which is then displaced as cyclopentadiene. 212213 This same class of compound can be formed in better yield by reacting azobenzene derivatives having chlorine 213 or mercury 39 substituents in the 2-position. Binuclear complexes have also been prepared by reacting the 2-chloro derivative (95) with further nickelocene (equation 209).215 [Nifo-CsHsfc]

+

p-MeC6H4N=NC6H4Me-p

(94)

88

Nickel Hydride, Alkyl and Aryl Complexes

I

I

Ni

Ni

Cl

—

Ni

(95)

A\

A; (96)

The benzalaniline derivative (96) has been prepared by a similar procedure.216 The structure of the product (94) of the reaction with 4-methylazobenzene has been confirmed crystallographically:214 the N = N bond distance is intermediate between that in free azobenzene (1.24 and 1.17 A) and that in the 7r-complex [Ni(CNBut)2(*72-PhN=NPh)] (1.39 A). The presence and position of the Ni—C bond in (94) and related complexes has also been confirmed chemically. For example, reduction with LiAlD4 leads to o-deuterated azobenzene. Electrochemical reduction has been shown to occur in two stages: initially a radical anion is formed in a reversible process while transfer of a second electron leads to dissociation.217 An unusual reaction has been observed on reacting the diphenylphosphido complex (97) with alkyne (equation 210); insertion into the nickel-phosphorus bond occurs to give (98). 240

Ph

/ \ (i7-C5H5)Ni\p/

-co Fe(CO)3

+

PhC^CPh

—

Ph2

I L y \ x-9y\^>^ 2.12 i . 4 > N i — l ^ ^ ^ e i C O h ~ 2.0\/155/ / - P P h 2 Ph

(210)

(97) (98)

The cluster compound (99) containing a bridging alkyne group has been isolated from the reaction of [Fe 3 (CO) 9 (EtC=CEt)] with [Ni(77-C5H5)2], while one of the products of the reaction of [{Ni(r7-C 5 H 5 )) 2 (HC=CR)] (R = Me, Bul) with Fe 3 (CO) 12 is the alkylidyne complex (100). 228 ' 418 Related complexes, e.g. (101), have been prepared by reacting nickelocene with RCH 2 Li or ArCH 2 MgCl, 231 ' 237 by reacting [NiCH 2 R(L)(77-C 5 H 5 )] with butyllithium or by

—Fe(CO) 3

I-Ni—

(CO) 3 (100) (101)

Nickel Hydride, Alky I and Aryl Complexes

89

a carbene transfer reaction involving [Cr=CPh(Br)(CO) 4 ]. 370 Cluster compounds are also the product of the reaction of [{NiCO(r?-C5H5))2] with [Ru 3 H(C 2 Bu t )(CO) 9 ] and [Ru 3 H(C 6 H 9 )(CO)9]. 229 ' 230 The product of the first reaction has been shown by X-ray crystallography to be the alkylidyne complex (102) in which the carbon atom interacts with four metal atoms. In the second (103), an allylic fragment is a-bonded to a nickel atom and a ruthenium atom and x-bonded - to two further ruthenium atoms. This arrangement is reminiscent of that observed in the product of the reaction of dilithiated pentaphenylaluminacyclopentadiene with nickel bromide (equation 211): a binuclear complex (104) is formed which has been shown by X-ray methods to contain ?73,7]4 and 77s organic groups in addition to a a-bonded allyl group.223

E« r X

C44

2M2

(OC)3Ru^c|o)i[|^Ru(CO)2

(OC)3Ru-(c/o)3\Jrtj#'

o

Nl

r

^Ru (CO) 3

^ > 2J0

(102)

(103)

R R

R

l(2-)AlR2Li+ IT^Y R

+

NiBr 2

—•

in/'

JiJfa* RW^Iioi R

\

0 3

Ri.46jl

L45

\ A.o\ L24C R

R

\—

{2U)

R

(104) R = Ph

Alkene-stabilized ?/-cyclopentadienylnickel alkyl complexes in which the alkene and (7-bonded group are part of the same organic ligand have also been reported. The simplest examples are formed by photolysis of a cyclopropylmethyl complex (equation 212),31 or by treating nickelocene with alkenylmagnesium halides (equation 213) or isopropylmagnesium bromide and an alkadiene (equation 214). 403 Other reactions which lead to complexes of this type are those between

O [NiCH 2 CHCH2CH 2 (CO)(77-C 5 H 5 )]

[Ni(ij-C 5 H 5 ) 2 ]

[Ni(77-C5H5)2]

+

+

^ ^ ^ y -

Pr'MgBr

+

M g C l

^ ^ y ^

—•

^

- ^

(TJ-CSHS^IJ

(i7-C 5 H 5 )N| J

+

(212)

C 5 H 5 MgCl (213)

^ (7 ? - 5 -C 5 H 5 )Ni N J ^

+

C 5 H 5 MgBr (214)

90

Nickel Hydride, Alkyl and Aryl Complexes

[Ni(cod) 2 ] and cyclopentadiene (equation 215),120<209 [Ni(7?4-diene)(77-C5H5)]+ (diene = cyclooctadiene, norbornadiene) and methoxide (equation 216) 66 and between nickelocene and alkynes (equation 217). 210 ' 21 ! ' 368 The product from the reaction of nickelocene with HCO 2 C=CCC>2-menthyl is chiral and the two diastereoisomers (105a) and (105b) could be partially separated by fractional crystallization.368 These reactions proceed presumably by 1,4-addition of the alkyne to a a-bonded cyclopentadiene group, and an analogous product has been isolated from the reaction with hexafluorobutyne. Other complexes isolated from this last reaction include

[Ni(cod)2]

+

\_y

—*

07-C5H5)NuQJ

|

+

cod

(215)

I.

z Ni v

BF 4 " +

NaOMe

- ^

N l

/

\

+

NaBF4

(216)

Ni

[Ni(r7-C5H5)2]

+ MeO2CC=CCO2Me

1.96/

\

/

\L98 CO2Me

—• S^^KlT^

\J-^i7CO2Me

Ni

N}

(a)

(b) (105)

I.

(106) R = CF 3

(107) R = CF 3

/

n.

(217)

Nickel Hydride, Alky I and Aryl Complexes

Table 9

[NiR(L)(i7-C5H5)] Complexes3

R Me

CD 3 Et Bu CH 2 =CHCH 2 CH 2 r;-C 5 H 4 CH 2 CH=CHCH 2 CH 2 CH 2 CHCH 2 Me3CCH2 2-naphthylCH2 PhCMe2CH9 Me3SiCH2 PhSCH2 CH 2 CH 2 CH— CH 2 CH 2 CH 2 CH— Me3SiC(Ph)H (CN) 2 CH HO^C MeC=C BuC^C PhC=C Ph p-MeC 6 H 4 MeCO EtCO PhCMe2CH2CO PhCO 7?-C5H4CH2C(=CHMe)CO VC5H 4 CH 2 CH 2 CO r/-C5H4CHMeCH2CO 77-C5H4CH2CHMeCO 7?-C5Ph4OCOC(Ph)=CPh PhN=CPh CyN=NCPh />-MeC 6 H 4 N=CPh p-MeC 6 H 4 N=C(mesityl) /7-MeC6H4N==C{C5H4Mn(CO)3} (OC)3Mn(7/-C5H4—) PPh3(OC)2Mn(r7-C5H4—) PhC=CPh(OC)2Mn(7;-C5H4—) CpFe(i7-C5H3Cl—) CpCo(?;-C4Ph3—) CpCo{?;-C4(CO2Me)3—} c

91

L

Ref.

P(OPh)3 P(OC6H4-o-Me) P(OMe)3 PPh3a PPh3 PPh3a PPh3a PPh3 (88) CO (89) CO PPh3 PPh3 PMe3 PPh3a PPh3 PPh3 PPh3 PPh3a PPh3 PBu3 PPh3a PPh3 PPh3a PMe3 PPh3a (87) PPh3a CO CO PMe3 CO CO (90) CO CO CO CO (91) CO CNCya CNC6H4Me-/7 CNC6H4Me-p CNC6H4Me-/7 PPh3 PPh3 PPh3 PPh3 PPh3 (93) PPh3

224 224 224 30,226 b ,401 c 401c 58,401 406 30 134,400 31 19,231 231 421 19,231 71 30 30 19 221 221 222 222,231 222 226b 19,401 401 402 402 421 402 134,400 134 400 400 28 227 220 225 225 225 15,96 96 96 15 219 219

a Earlier work is discussed and tabulated in ref. 1, pp. 215-234. 77-C5D5 complex.

b

rj-CsMcs complex.

92

Nickel Hydride, Alky I and Aryl Complexes

(106), in which 1,2-addition of a second alkyne molecule has occurred, and the most unusual tetramer (107) in which the presence of 77', 172, r/3, yf and rj5 organic groups has been established crystallographically5128 and in which each nickel atom has a closed shell configuration. Compound (107) can be more rationally prepared by reacting the dinuclear alkyne complex [{NKTJ-CSHS)} 2 (CF 3 C=CCF 3 )] with further alkyne. A similar reaction carried out with [{NiSCF3(77-C5H5)}2] gives a mixture of six products, two of which (108,109) contain nickel-carbon d-bonds,128 while

(108) R = CF 3

(109) R = CF 3

(110) R = CF 3

the product of the reaction of bis(trifluoromethyl)diazomethane with nickelocene is a purple solid which is suggested, on the basis of ]H and 19 F NMR measurements, to have structure (HO). 3 7

Table 10 Miscellaneous NiR(77-C5H5) Complexes8

a

Complex

Ref.

Ni{7?',7?2-(CH2)3CH==CH2}(77-C5H5)] Ni{?;l,T/2-(CH2)3CMe=CH2KT/-C5H5)] Ni|771,772-(CH2)2CHMeCH==CH2K?7-C5H5)] Ni{V,T/2-(CH2)2CMe2CMe=CH2}(i;-C5H5)] Ni(r/i,r;2-CH2CHMeCMe2CH=CH2)(77-C5H5)] Ni(r/',?72-CH2CMe2CH=CH2)(r7-C5H5)] Ni(r;l,772-C8H13)(77-C5H5)]a Ni(771,r?2-C8H,3)(77-Me3SiC5H4)] Ni(771,r72-C8H13)(r;-Et3GeC5H4)] Ni(?;l,7;2-C8H12OMe)(?;-C5H5)] Ni(y,7/2-C7H8OMeX77-C5H5)] Ni(7/1,772-COCH2CH2CH=CH2)(77-C5H5)] Ni|r;1,r;2-C5H5C2(CO2menthyl)H}(77-C5H5)] :Ni{7?',772-C5H5C2(CO2H)2K77-C5H5)] Ni{771,r72-C5H5C2(CO2menthyl2)}(r;-C5H5)] Ni{7/l,r72-C5H5C2(CO2H)CO2menthyl}(T;-C5H5)](105) Ni{7/',r72-C5H5C2(CF3)2}(r;-C5H5)]a i N i l V ^ - C s H s C ^ C F j ^ - C s H s ) ] (106) NiC(CF3)2N2C(CF3)2C5H5(r;-C5H5)] (110) |NiC2(CF3)2(r7-C5H5)}4] (107) Ni(COCMeC9Hn)07-C5H5)] {Ni(T/-C5H5)}3CPh]a (101) : {Ni(T/-C5H5)}3CCMe3] {Ni(77-C5H5)}3CSiMe3] NiCEt(77-C5H5)Fe2(CO)7] (100) NiC2Me(77-C5H5)Fe2(CO)6] (99) NiCCHBut(7?-C5H5)Ru3(CO)9] (102) NiC6H9(r;-C5H5)Ru3(CO)9] (103) (7/-C5Ph5)NiC3Ph3Ni(T7-C4Ph4)] (104)

403 403 403 403 403 403 209 120 120 66 66 31 368 368 368 368 5, 128 5, 128 37 5, 128 37, 73, 218 231, 270 231 231 228 228 229 230 223

Earlier work is discussed and tabulated in ref. 1, pp. 215-234.

Nickel Hydride, Alkyl and Aryl Complexes

93

Nickelocene reacts with dimethylketene (equation 218) to form a complex which was originally formulated as containing a 7r-bonded four-membered lactone but which has been shown by X-ray crystallography to be in reality the nickel acyl derivative (111). This complex can be regarded as the product of the insertion of one ketene molecule into a ry'-CsHs group and the 1,2-addition of a second. 36 ' 73 ' 218 <^~^j> 2.172 1.895

[Ni(77-C5H5)2]

+

2Me2C=C=O

—»

11-716

°^Nll888 9 "J ^1024 Me

(218)

^r^KMe (/Me (111)

REFERENCES 1. P. W. Jolly and G. Wilke, The Organic Chemistry of Nickel', Academic Press, New York, 1974, vol. 1, chapter 5. 2. B. Cetinkaya, M. F. Lappert, J. McMeeking and D. E. Palmer, J. Chem. Soc, Dalton Trans., 1973, 1202. 3. M. R. Churchill, K. L. Kalra and M. V. Veidis, Inorg. Chem., 1973,12, 1656. 4. L. Sacconi, P. Dapporto, P. Stoppioni, P. Innocenti and C. Benelli, Inorg. Chem., 1977,16,1669. 5. J. L. Davidson, R. Herak, L. Manojlovic-Muir, K. W. Muir and D. W. A. Sharp, J. Chem. Soc, Chem. Commun., 1973,865. 6. D. R. Fahey, J. Org. Chem., 1972, 37,4471. 7. D. R. Fahey, J. Organomet. Chem., 1973, 57, 385. 8. E. A. Jeffery, Aust. J. Chem., 1973, 26, 219. 9. H. H. Karsch and H. Schmidbaur, Angew. Chem., 1973,85,910 (Angew. Chem., Int. Ed. Engl. 1973,12, 853). 10. H. F. Klein, Angew. Chem., 1973, 85,403 {Angew. Chem., Int. Ed. Engl., 1973,12,402). 11. H. F. Klein and H. H. Karsch, Chem. Ber., 1973,106,1433. 12. H. F. Klein and H. H. Karsch, Chem. Ber., 1973,106, 2438. 13. K. J. Klabunde and J. Y. F. Low, J. Organomet. Chem., 1973, 51, C33. 14. P. Miiller, E. Uhlig and D. Walther, Z. Chem., 1973,13,141. 15. A. N. Nesmeyanov, E. G. Perevalova, L. I. Khomik and L. I. Leonteva, Dokl. Chem. {Engl. Transl.), 1973, 209, 277. 16. A. Areas and P. Royo, Inorg. Chim. Ada, 1978, 30, 205. 17. S. Otsuka, A. Nakamura, T. Yoshida, M. Naruto and K. Ataka, J. Am. Chem. Soc, 1973,95, 3180. 18. H. F. Klein and H. H. Karsch, Chem. Ber., 1972,105, 2628. 19. J. Thomson and M. C. Baird, Inorg. Chim. Acta, 1973, 7,105. 20. G. Tieghi and M. Zocchi, J. Organomet. Chem., 1973, 57, C90. 21. A. Yamamoto, T. Yamamoto, T. Saruyama and Y. Nakamura, J. Am. Chem. Soc, 1973, 95,4073. 22. T. Yamamoto and A. Yamamoto, J. Organomet. Chem., 1973,57, 127. 23. W. C. Drinkard and R. V. Lindsey (E.I. du Pont), US Pat. 3 676 475 (1972). 24. D. R. Fahey (Phillips Petroleum), US Pat. 3 686 245 (1972) {Chem. Abstr., 1972, 77, 140 298). 25. E. Uhlig and D. Walther, Coord. Chem. Rev., 1980, 33, 3. 26. B. L. Barnett and C. Kruger, J. Organomet. Chem., 1974,77,407. 27. M. A. Bennett, P. W. Clark, G. B. Robertson and P. O. Whimp, J. Organomet. Chem., 1973, 63, Cl 5. 28. C. W. Bird and E. M. Briggs, J. Organomet. Chem., 1974,69, 311. 29. J. Browning, M. Green, J. L. Spencer and F. G. A. Stone, J. Chem. Soc, Dalton Trans., 1974, 97. 30. J. M. Brown and K. Mertis, J. Chem. Soc, Perkin Trans. 2, 1973, 1993. 31. J. M. Brown, J. A. Conneely and K. Mertis, J. Chem. Soc, Perkin Trans. 2, 1974, 905. 32. B. Bussemeier, P. W. Jolly and G. Wilke, J. Am. Chem. Soc, 1974,96, 4726. 33. D. J. Brauer, C. Kruger, P. J. Roberts and Y. H. Tsay, Chem. Ber., 1974,107, 3706. 34. H. Masai, K. Sonogashira and N. Hagihara, J. Organomet. Chem., 1971, 26, 271. 35. L. Cassar and A. Giarrusso, Gazz. Chim. Hal., 1973,103, 793. 36. M. R. Churchill, B. G. DeBoer and J. J. Hackbarth, Inorg. Chem., 1974,13, 2098. 37. J. Clemens, M. Green and F. G. A. Stone, J. Chem. Soc, Dalton Trans., 1974, 93.

94 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 59. 60. 61. 62. 63. 64. 65. 66. 67. 68. 69. 70. 71. 72. 73. 74. 75. 76. 77. 78. 79. 80. 81. 82. 83. 84. 85. 86. 87. 88. 89. 90. 91. 92. 93. 94. 95. 96. 97. 98. 99. 100. 101. 102.

Nickel Hydride, Alkyl and Aryl Complexes F. A. Cotton, B. A. Frenz and D. L. Hunter, /. Am. Chem. Soc, 1974, 96,4820. R. J. Cross and N. H. Tennent, J. Organomet. Chem., 1974, 72, 21. C. H. Davies, C. H. Game, M. Green and F. G. A. Stone, J. Chem. Soc, Dalton Trans., 1974, 357. P. Dapporto and L. Sacconi, Inorg. Chim. Acta, 1974,9, L2. D. R. Fahey and B. A. Baldwin, J. Organomet. Chem., 1974, 70, Cl 1. H. Trinh, Dissertation, Ruhr-Universitat Bochum (1980). M. L. H. Green and H. Munakata, J. Chem. Soc, Dalton Trans., 1974, 269. G. Huttner and H. Lorenz, Chem. Ber., 1974,107,996. D. G. Holah, A. N. Hughes, B. C. Hui and K. Wright, Can. J. Chem., 1974, 52, 2990. D. G. Holah, A. N. Hughes, B. C. Hui and K. Wright, Inorg. Nucl. Chem. Lett., 1973,9, 835. D. G. Holah, A. N. Hughes and B. C. Hui, Inorg. Nucl. Chem. Lett., 1974,10,427. K. Jonas, Angew. Chem., 1973,85,1050; Angew Chem., Int. Ed. Engl, 1973,12, 997. K. Jacob, I. Wiswedel, T. Zeine and K. H. Thiele, Z. Anorg. Allg. Chem., 1973,402,193. K. Jacob, Z. Chem., 1973,13,475. K. Jonas, J. Organomet. Chem., 1974, 78, 273. H. H. Karsch, H. F. Klein and H. Schmidbaur, Chem. Ber., 1974,107,93. H. H. Karsch and H. Schmidbaur, Chem. Ber., 1974,107, 3684. C. Kruger and Y. H. Tsay, Angew. Chem., 1973, 85, 1051 (Angew. Chem., Int. Ed. Engl., 1973, 12, 998). H. F. Klein, H. H. Karsch and W. Buchner, Chem. Ber., 1974,107, 537. K. J. Klabunde, J. Y. F. Low, H. F. Efner, J. Am. Chem. Soc, 1974, 96,1984. Y. Kiso, K. Tamao and M. Kumada, J. Organomet. Chem., 1974, 76,95. M. F. Lappert and G. Speier, J. Organomet. Chem., 1974,80, 329. G. Longoni, P. Chini, F. Canziani and P. Fantucci, Gazz. Chim. Ital, 1974,104, 249. P. Meakin, R. A. Schunn and J. P. Jesson, J. Am. Chem. Soc, 1974,96, 277. J. Miiller, H. Dorner, G. Huttner and H. Lorenz, Angew. Chem., 1973,85,1117 (Angew. Chem., Int. Ed. Engl., 1973,12, 1005). R. G. Miller, D. R. Fahey, H. J. Golden and L. C. Satek, J. Organomet. Chem., 1974,82,127. A. Nakamura and S. Otsuka, Tetrahedron Lett., 1974, 463. S. Otsuka, K. Tani, I. Kato and O. Teranaka, J. Chem. Soc, Dalton Trans., 1974, 2216. G. Parker, A. Salzer and H. Werner, J. Organomet. Chem., 1974, 67, 131. G. W. Parshall, J. Am. Chem. Soc, 1974,96, 2360. K. Stanley, R. A. Zelonka, J. Thomson, P. Fiess and M. C. Baird, Can. J. Chem., 1974, 52,1781. G. Tieghi and M. Zocchi, Cryst. Struct. Commun., 1973, 2, 557. G. Tieghi and M. Zocchi, Cryst. Struct. Commun., 1973, 2, 561. R. Taube and D. Steinborn, J. Organomet. Chem., 1974, 65, C9. D. Walther, Z. Anorg. Allg. Chem., 1974, 405, 8. D. A. Young, J. Organomet. Chem., 1974, 70,95. D. R. Fahey (Phillips Petroleum), US Pat., 3 808 246 (1974) (Chem. Abstr., 1974,81, 25 810). D. R. Fahey (Phillips Petroleum), US Pat., 3 818 063 (1974) (Chem. Abstr., 1974,81, 78 092). M. Aresta, C. F. Nobile and A. Sacco, Inorg. Chim. Acta, 1975,12,167. E. Bartsch, E. Dinjus and E. Uhlig, Z. Chem., 1975,15, 317. J. Casabo, J. M. Coronas and J. Sales, Inorg. Chim. Acta, 1974,11, 5. L. Cassar, M. Foa, M. Camia and M. P. Lachi, Gazz. Chim. Ital, 1974,104, 665. H. J. Callot, T. Tschamber, B. Chevrier and R. Weiss, Angew. Chem., 1975,87, 545 (Angew. Chem., Int. Ed. Engl., 1975,14,567). B. Corain and G. Favero, J. Chem. Soc, Dalton Trans., 1975, 283. J. M. Coronas and J. Sales, J. Organomet. Chem., 1975,94,107. J. M. Coronas, O. Rossell and J. Sales, J. Organomet. Chem., 1975, 97,473. G. Favero, A. Frigo and A. Turco, Gazz. Chim. Ital, 1974,104, 869. C. A. Ghilardi, S. Midollini and L. Sacconi, Inorg. Chem., 1975,14,1790. M. C. Gallazzi, L. Porri and G. Vitulli, J. Organomet. Chem., 1975,97,131; M. C. Gallazzi, T. L. Hanlon, G. Vitulli and L. Porri, J. Organomet. Chem., 1971, 33, C45. R. H. Grubbs, D. D. Carr and P. L. Burk, in 'Organotransition Metal Chemistry', ed. Y. Ishii and M. Tsutsui, Plenum, New York, 1975, p. 135. J. M. Brown and K. Mertis, /. Organomet. Chem., 1973, 47, C5. E. A. Jeffery and A. Meisters, J. Organomet. Chem., 1974,82, 315. K. Jacob and R. Niebuhr, Z. Chem., 1975,15, 32. H. Johansen and B. Roos, Int. J. Quantum Chem., Symp., 1974,8, 137. K. Jacob, K. H. Thiele, C. Keilberg'and R. Niebuhr, Z. Anorg. Allg. Chem., 1975, 415, 109. A. Gleizes, M. Dartiguenave, Y. Dartiguenave, J. Galy and H. F. Klein, J. Am. Chem. Soc, 1977, 99, 5187. G. K. McEwen, C. J. Rix, M. F. Traynor and J. G. Verkade, Inorg. Chem., 1974,13, 2800. U. N. Dzhemilev, A. G. Kukovinets and G. A. Tolstikov, Bull Acad. Sci. USSR, Div. Chem. Sci., 1978, 1200. A. N. Nesmeyanov, E. G. Perevalova, L. I. Leonteva and L. I. Khomik, Bull Acad. Sci. USSR, Div. Chem. Sci., 1974,907. A. N. Nesmeyanov, L. S. Isaeva, L. N. Lorens and V. S. Kolesov, Dokl Chem. (Engl. Transl), 1974,219, 835; see also Chem. Abstr., 1976,85, 201 404. K. Oguro, M. Wada and R. Okawara, J. Chem. Soc, Chem. Commun., 1975, 899. L. Sacconi, A. Orlandini and S. Midollini, Inorg. Chem., 1974,13, 2850. T. Saito, Chem. Lett., 1974, 1545. L. Sacconi, C. A. Ghilardi, C. Mealli and F. Zanobini, Inorg. Chem., 1975,14, 1380. W. Seidel and D. Geinitz, Z. Chem., 1975,15, 71.

Nickel Hydride, Alkyl and Aryl Complexes 103. 104. 105. 106. 107. 108. 109. 110. 111. 112. 113. 114. 115. 116. 117. 118. 119. 120. 121. 122. 123. 124. 125. 126. 127. 128. 129. 130. 131. 132. 133. 134. 135. 136. 137. 138. 139. 140. 141. 142. 143. 144. 145. 146. 147. 148. 149. 150. 151. 152. 153. 154. 155. 156. 157. 158. 159. 160. 161. 162. 163. 164. 165.

95

W. Seidel, G. Kreisel and B. Naber, Z. Anprg. Allg. Chem., 1975, 413, 261. A. Stasko, A. Tkac, R. Pfikryl and L. Malik, J. Organomet. Chem., 1975, 92, 253. A. Stasko, A. Tkac, L. Malik and V. Adamcik, J. Organomet. Chem., 1975, 92, 261. J. Thomson and M. C. Baird, Inorg. Chim. Ada, 1975,12, 105. R. Taube and G. Honymus, Angew. Chem., 1975, 87, 291 (Angew. Chem., Int. Ed. Engl, 1975, 14, 261). V. S. Tkach, F. K. Smidt, V. V. Saraev and A. V. Kalabina, Kinet. Catal. {Engl. Transl), 1974,15, 549. M. Uchino, K. Asagi, A. Yamamoto and S. Ikeda, J. Organomet. Chem., 1975,84, 93. E. Uhlig and E. Dinjus, Z. Anorg. Allg. Chem., 1975, 418,45. M. Wada, Inorg. Chem., 1975,14,1415. M. Wada and T. Wakabayashi, J. Organomet. Chem., 1975, 96, 301. A. Yamamoto, T. Yamamoto, M. Takamatsu, T. Saruyama and T. Nakamura, in 'Organotransition Metal Chemistry', ed. Y. Ishiu and M. Tsutsusi, Plenum, New York, 1975, p. 281. M. Zocchi and G. Tieghi, J. Chem. Soc, Dalton Trans., 1975, 1740. W. B. Hughes and D. R. Fahey (Phillips Petroleum), US Pat. 3 887 441 (1975) (Chem. Abstr., 1975,83, 123 303). B. L. Barnett, C. Kriiger, Y. H. Tsay, R. H. Summerville and R. Hoffmann, Chem. Ber., 1977, 110, 3900. H. Imoto, H. Moriyama, T. Saito and Y. Sasaki, J. Organomet. Chem., 1976,120,453. J. K. Kochi, Pure Appl. Chem., 1980, 52, 571. J. M. Coronas, O. Rossell and J. Sales, J. Organomet. Chem., 1976,121, 265. Y. A. Sorokin, N. V. Perevozchikova and V. A. Titov, Tr. Khim. Khim. Tekhnol., 1975, 21. M. A. Bennett and P. W. Clark, J. Organomet. Chem., 1976,110, 367. P. Stoppioni, P. Dapporto and L. Sacconi, Inorg. Chem., 1978,17, 718. D. J. Brauer, C. Kruger, P. J. Roberts and Y. H. Tsay, Angew. Chem., 1976, 88, 52 (Angew. Chem., Int. Ed. Engl., 1976,15,48). J. Browning and B. R. Penfold, J. Cryst. Mol. Struct., 1974, 4, 347. B. Chevrier and R. Weiss, J. Am. Chem. Soc, 1976,98, 2985. H. C. Clark and A. Shaver, Can. J. Chem., 1975, 53, 3462. M. J. D'Aniello and E. K. Barefield, /. Am. Chem. Soc, 1976, 98, 1610. J. L. Davidson and D. W. A. Sharp, J. Chem. Soc, Dalton Trans., 1976, 1123. H. torn Dieck and M. Svoboda, Chem. Ber., 1976,109,1657. J. D. Druliner, A. D. English, J. P. Jesson, P. Meakin and C. A. Tolman, J. Am. Chem. Soc, 1976, 98, 2156. M. J. Doyle, J. McMeeking and P. Binger, J. Chem. Soc, Chem. Commun., 1976, 376. A. D. English, P. Meakin and J. P. Jesson, J. Am. Chem. Soc, 1976, 98,422. P. Eilbracht, Chem. Ber., 1976,109, 3136. P. Eilbracht, J. Organomet. Chem., 1976,120, C37. G. Favero and A. Turco, J. Organomet. Chem., 1976,105, 389. D. R. Fahey and J. E. Mahan, J. Am. Chem. Soc, 1976, 98, 4499; US Pat. 4 115 470 and 4 120 907 (1978). M. Foa and L. Cassar, J. Chem. Soc, Dalton Trans., 1975, 2572. P. E. Garrou and R. F. Heck, J. Am. Chem. Soc, 1976, 98, 4115. G. Huttner, O. Orama and V. Bejenke, Chem. Ber., 1976,109, 2533. K. Jonas, Angew. Chem., 1976,88, 51 (Angew. Chem., Int. Ed. Engl, 1976,15,47). J. Jonas, D. J. Brauer, C. Kruger, P. J. Roberts and Y. H. Tsay, J. Am. Chem. Soc, 1976, 98, 74. K. Jacob, E. Panse and K. H. Thiele, Z. Anorg. Allg. Chem., 1976,425, 151. K. Jonas, K. R. Porschke, C. Kruger and Y. H. Tsay, Angew. Chem., 1976, 88, 682 (Angew. Chem., Int. Ed. Engl, 1976,15,621). H. F. Klein and H. H. Karsch, Chem. Ber., 1976,109, 2524. H. F. Klein and H. H. Karsch, Chem. Ber., 1976,109, 2515. P. Meakin, A. D. English and J. P. Jesson, J. Am. Chem. Soc, 1976, 98,414. C. J. Moulton and B. L. Shaw, J. Chem. Soc, Dalton Trans., 1976, 1020. S. B. Miller and M. F. Hawthorne, J. Chem. Soc. Chem. Commun., 1976, 786. A. N. Nesmeyanov, L. S. Isaeva, L. N. Lorens and V. S. Kolesov, Dokl Chem. (Engl. Transl), 1975,223, 477. Y. Nakamura, K. I. Maruya and T. Mizoroki, J. Organomet. Chem., 1976,104, C5. L. Sacconi, P. Dapporto and P. Stoppioni, Inorg. Chem., 1976,15, 325. T. Saruyama, T. Yamamoto and A. Yamamoto, Bull Chem. Soc. Jpn., 1976, 49, 546. L. Sacconi, P. Dapporto and P. Stoppioni,J. Organomet. Chem., 1976,116, C33. R. A. Schunn, Inorg. Chem., 1976,15, 208. H. G. von Schnering, K. Peters and E. M. Peters, Chem. Ber., 1976,109,1665. M. Seno, S. Tsuchiya, M. Hidai and Y. Uchida, Bull Chem. Soc Jpn., 1976, 49, 1184. D. Steinborn, Z. Chem., 1976,16, 328. S. Takahashi, Y. Suzuki, K. Sonogashira and N. Hagihara, J. Chem. Soc, Chem. Commun., 1976, 839. M. Di Vaira, C. A. Ghilardi and L. Sacconi, Inorg. Chem., 1976,15, 1555. M. Wada and T. Shimohigashi, Inorg. Chem., 1976,15,954. T. Yamamoto, Y. Nakamura and A. Yamamoto, Bull. Chem. Soc Jpn., 1976, 49, 191. T. Yamamoto, T. Saruyama, Y. Nakamura and A. Yamamoto, Bull Chem. Soc Jpn., 1976, 49, 589. T. Yamamoto and A. Yamamoto, J. Organomet. Chem., 1976,117, 365. K. Fischer, K. Jonas, P. Misbach, R. Stabba and G. Wilke, Angew. Chem., 1973,85, 1002 (Angew. Chem. Int. Ed. Engl, 1973,12,943). C. S. Cundy, J. Organomet. Chem., 1974, 69, 305.

96

Nickel Hydride,

Alky I and Aryl

Complexes

166. J. Browning, M. Green, B. R. Penfold, J. L. Spencer and F. G. A. Stone, J. Chem. Soc, Chem. Commun., 1973,31. 167. T. Saito, H. Munakata and H. Imoto, Inorg. Synth., 1977,17, 83. 168. H. Munakata and T. Saito, Inorg. Synth., 1977,17, 88. 169. T. Saito, M. Nakajima, A. Kobayashi and Y. Sasaki, J. Chem. Soc, Dalton Trans., 1978, 482. 170. N. V. Petrushanskaya, A. 1. Kurapova, N. M. Bodionova, T. V. Fedotova and V. S. Feldblyum, J. Gen. Chem. USSR (Engl. TransL), 1978, 48, 2061. 171. A. N. Nesmeyanov, L. S. Isaeva and L. N. Morozova, Inorg. Chim. Acta, 1979, 33, LI73. 172. A. N. Nesmeyanov, L. S. Isaeva and L. N. Lorens, J. Organomet. Chem., 1977,129,421. 173. R. Hoffmann, B. E. R. Schilling, R. Bau, H. D. Kaesz and D. M. P. Mingos, J. Am. Chem. Soc, 1978,100, 6088. 174. T. F. Koetzle, R. K. McMullan, R. Bau, D. W. Hart, R. G. Teller, D. L. Tipton and R. D. Wilson, Adv. Chem. Ser., 1978,167,61; T. F. Koetzle, J. Muller, D. L. Tipton, D. W. Hart and R. Bau, J. Am. Chem. Soc, 1979, 101,5631. 175. H. Bonnemann, Angew. Chem., 1970,82,699 (Angew. Chem., Int. Ed. Engl., 1970,9,736); H. Bonnemann, C. Grard, W. Kopp and G. Wilke, Pure Appl. Chem., 1971, 6, 265. 176. K. Jonas and G. Wilke, Angew. Chem., 1969, 81, 534 (Angew. Chem., Int. Ed. Engl., 1969, 8, 519). 177. G. Longoni, P. Chini and A. Cavalieri, Inorg. Chem., 1976,15, 3025. 178. R. W. Broach, L. F. Dahl, G. Longoni, P. Chini, A. J. Schultz and J. M. Williams, Adv. Chem. Ser., 1978, 167,93; R. W. Broach, Dissertation, Univ. Wisconsin (1977). 179. P. Chini, G. Longoni, S. Martinengo and A. Ceriotti, Adv. Chem. Ser., 1978,167,1; P. Chini, Gazz. Chim. Ital, 1979,109, 225; P. Chini, G. Longoni and S. Martinengo, Chim. Ind. (Milan), 1978, 60,989. 180. L. J. Farrugia, J. A. K. Howard, P. Mitrprachachon, J. L. Spencer, F. G. A. Stone and P. Woodward, J. Chem. Soc, Chem. Commun., 1978, 260. 181. G. Longoni, P. Chini, F. Canziani and P. Fantucci, J. Chem. Soc, Chem. Commun., 1971,470. 182. C. W. Weston, A. W. Verstuyft, J. H. Nelson and H. B. Jonassen, Inorg. Chem., 1977,16, 1313. 183. C. A. Tolman, J. Am. Chem. Soc, 1970, 92,4217. 184. C. A. Tolman, D. H. Gerlach, J. P. Jesson and R. A. Schunn, /. Organomet. Chem., 1974,65, C23. 185. M. L. H. Green and T. Saito, J. Chem. Soc, Chem. Commun., 1969,208; M. L. H. Green, T. Saito and P. J. Tanfield, J. Chem. Soc. (A), 1971,152; M. L. H. Green, H. Munakata and T. Saito, J. Chem. Soc, Chem. Commun., 1969, 1287. 186. L. J. Radonovich, K. J. Koch and T. A. Albright, Inorg. Chem., 1980,19, 3373. 187. M. L. H. Green, H. Munakata and T. Saito, J. Chem. Soc (A), 1971, 469. 188. D. G. Holah, A. N. N. Hughes, B. C. Hui and C. T. Kan, Can. J. Chem., 1978, 56, 2552. 189. U. A. Gregory and B. T. Kilbourn, private commun. to B. A. Frenz and J. A. Ibes, quoted in Transition Metal Hydrides' Dekher, New York, 1971, p. 45. 190. G. A. Chukhadzhyan and Z. K. Evoyan, Arm. Khim. Zh.,\91\, 24,530 (Chem. Abstr., 1971,75,118 393); G. A. Chukhadzhyan, Z. K. Evoyan and G. A. Keiorkion, Abstr. Int. Conf. Organomet. Chem. 5th., 1971, vol. 2, p. 187. 191. K. Jonas and G. Wilke, Angew. Chem., 1970,82, 295 (Angew. Chem., Int. Ed. Engl, 1970,9, 312). 192. K. Jonas and K. R. Porschke, Angew. Chem., 1979, 91, 521 (Angew. Chem., Int. Ed. Engl., 1979, 18, 488). 193. K. R. Porschke, Dissertation, Ruhr-Universitat Bochum (1975). 194. K. Jonas, Habilitationsschrift, Ruhr-Universitat Bochum (1978). 195. K. Fischer, Dissertation, Ruhr-Universitat Bochum (1973). 196. A. N. Nesmeyanov, L. S. Isaeva and L. N. Lorens, Dokl. Chem. (Engl. TransL), 1976, 229,498. 197. J. M. Huggins and R. G. Bergman, J. Am. Chem. Soc, 1979,101,4410. 198. K. Maruyama, T. Ito and A. Yamamoto, J. Organomet. Chem., 1978,155, 359; ibid., 1975,90, C28. 199. W. Keim, B. Hoffmann, R. Lodewick, M. Peuckert, G. Schmitt, J. Fleischhauer and U. Meier, J. Mol. Catal, 1979,6,79. 200. K. Maruyama, T. Ito and A. Yamamoto, J. Organomet. Chem., 1978,157, 463. 201. K. Jacob, E. Pietzner, S. Vastag and K. H. Thiele, Z. Anorg. Allg. Chem., 1977, 432, 187. 202. H. J. Dohring and P. W. Jolly, unpublished results, 1977. 203. P. W. Jolly, K. Jonas, C. Kruger and Y. H. Tsay, J. Organomet. Chem., 1971, 33,109. 204. B. L. Barnett and C. Kruger, J. Organomet. Chem., 1972, 42, 169. 205. S. Jager and P. W. Jolly, unpublished results, 1978. 206. B. Bogdanovic, M. Kroner and G. Wilke, Liebigs Ann. Chem., 1966, 699, 1. 207. O. S. Mills and E. F. Paulus, J. Chem. Soc, Chem. Commun., 1966, 738. 208. H. Bonnemann, Dissertation, Techn. Hoch. Aachen (1967). 209. K. W. Barnett, J. Organomet. Chem., 1970, 21, 477. 210. M. R. Churchill and M. V. Veidis, J. Chem. Soc (^4), 1971, 3463. 211. M. Dubeck, J. Am. Chem. Soc, 1960, 82, 6193. 212. J. P. Kleiman and M. Dubeck, J. Am. Chem. Soc, 1963, 85, 1544; M. I. Bruce, M. Z. Iqbal and F. G. A. Stone, J. Chem. Soc. (A), 1970, 3204. 213. Y. A. Ustynyuk and I. V. Barinov, J. Organomet. Chem., 1970, 23, 551. 214. V. A. Semion, I. V. Baronov, Y. A. Ustynyuk and Y. T. Struchkov, J. Struct. Chem. (Engl. Transl), 1972, 13,512. 215. I. V. Barinov, T. I. Voyevodskaya and Y. A. Ustynyuk, J. Organomet. Chem., 1971,30, C28; Vestn. Mosk. Univ. Ser. 2: Khim., 1978,19, 453 (Chem. Abstr., 1979, 90, 23 231). 216. Y. A. Ustynyuk, V. A. Chertkov and I. V. Barinov, J. Organomet. Chem., 1971, 29, C53. 217. N. R. Popodko, A. A. Pozdeeva, S. I. Zhdanov and M. S. Miftakhov, J. Gen. Chem. USSR (Engl. TransL), 1978,48,2315. 218. M. Sato, K. Ichibori and F. Sato, J. Organomet. Chem., 1971, 26, 267. 219. K. Yasufuku and H. Yamazaki, J. Organomet. Chem., 1976,121, 405.

Nickel Hydride, Alkyl and Aryl Complexes

97

220. Y. Yamamoto and H. Yamazaki, Bull Chem. Soc Jpn., 1975, 48, 3691. 221. F. Sato, J. Noguchi and M. Sato, J. Organomet. Chem., 1976,118,117. 222. K. Sonogashira, T. Yatake, Y. Tohda, S. Takahashi and N. Hagihara, J. Chem. Soc, Chem. Commun., 1977,291. 223. H. Hoberg, R. Krause-Going, C. Kriiger and J. C. Sekutowski, Angew. Chem., 1977,89,179 (Angew. Chem., Int. Ed. Engl., 1977,16,183). 224. N. Kuhn and H. Werner, Synth. React. Inorg. Metal-Org. Chem., 1978,8, 249. 225. D. N. Nesmeyanov, L. I. Leonteva and L. I. Khomik, Bull. Acad. Sci. USSR, Div. Chem. Sci., 1976, 1571. 226. T. Mise and H. Yamazaki, J. Organomet. Chem., 1976,164, 391. 227. R. D. Adams, D. F. Chodosh, N. M. Golembeski and E. C. Weissman, J. Organomet. Chem., 1979,172, 251. 228. V. Raverdino, S. Aime, L. Milone and E. Sappa, Inorg. Chim. Acta, 1978, 30, 9; A. Marinetti, E. Sappa, A. Tiripicchio and M. T. Camellini, J. Organomet. Chem., 1980,197, 335. 229. E. Sappa, A. Tiripicchio and M. T. Camellini, J. Chem. Soc, Chem. Commun., 1979, 254; Inorg. Chim. Acta, 1980,41,11. 230. D. Osella, E. Sappa, A. Tiripicchio and M. T. Camellini, Inorg. Chim. Acta, 1979,34, L289; Inorg. Chim. Acta, 1980,42,183. 231. B. L. Booth and G. C. Casey, J. Organomet. Chem., 1979,178, 371. 232. H. Schenkluhn, W. Scheidt, B. Weimann and M. Zahres, Angew. Chem., 1979, 91, 429 {Angew. Chem., Int. Ed. Engl., 1979,18,401). 233. J. Thomson and M. C. Baird, Can. J. Chem., 1973, 51,1179. 234. Y. Yamamoto, H. Yamazaki and N. Hagihara, Bull. Chem. Soc. Jpn. 1968,41,532; J. Organomet. Chem., 1969,18,189. 235. M. D. Rausch, Y. F. Chang and H. B. Gordon, Inorg. Chem., 1969, 8, 1355. 236. P. M. Treichel and R. L. Shubkin, Inorg. Chim. Acta, 1968, 2, 485. 237. T. I. Voyevodskaya, I. M. Pribytkova and Y. A. Ustynyuk, J. Organomet. Chem., 1972, 37,187. 238. M. R. Churchill and T. A. O'Brien, J. Chem. Soc (A), 1968, 2970; ibid., 1969, 266; ibid., 1970, 161. 239. J. Thomson, W. Keeney, M. C. Baird and W. F. Reynolds, J. Organomet. Chem., 1972, 40, 205. 240. K. Yasufuku and H. Yamazaki, J. Organomet. Chem., 1972, 35, 367; B. L. Barnett and C. Kruger, Cryst. Struct. Commun., 1973, 2, 347. 241. P. W. Jolly, S. Stobbe, G. Wilke, R. Goddard, C. Kruger, J. C. Sekutowski and Y. H. Tsay, Angew. Chem., 1978, 90, 144 (Angew. Chem., Int. Ed. Engl, 1978,17,124). 242. C. Kruger, J. C. Sekutowski, H. Berke and R. Hoffmann, Z. Naturforsch., Teil B, 1978, 33, 1110. 243. D. R. Burnham (I.C.I. Ltd.), Ger. Offen. 2 525 404 (1975). 244. B. Henc, P. W. Jolly, R. Salz, S. Stobbe, G. Wilke, R. Benn, R. Mynott, K. Seevogel, R. Goddard and C. Kruger, / . Organomet. Chem., 1980,191,449. 245. R. Mynott, unpublished results (1979). 246. B. Bogdanovic, H. Bonnemann and G. Wilke, Angew. Chem., 1966, 78, 591 (Angew. Chem., Int. Ed. Engl, 1966, 5, 582); H. Schenkluhn, Dissertation, Ruhr-Universitat Bochum, 1971. 247. B. Barnett, B. Biissemeier, P. Heimbach, P. W. Jolly, C. Kruger, I. Tkatchenko and G. Wilke, Tetrahedron Lett., 1972, 1457. 248. B. Biissemeier, Dissertation, Ruhr-Universitat Bochum, 1973. 249. H. Schenkluhn, Dissertation, Ruhr-Universitat Bochum, 1971. 250. F. Heydenreich, A. Mollbach, G. Wilke, H. Dreeskamp, E. G. Hoffmann, G. Schroth, K. Seevogel and W. Stempfle, Isr. J. Chem., 1972,10, 293. 251. M. Anton, J. M. Coronas, G. Muller, J. Sales and M. Seco, Inorg. Chim. Acta, 1979, 36, 173. 252. M. Wada, K. Oguro and Y. Kawasaki, J. Organomet. Chem., 1979,178, 261. 253. D. R. Fahey and B. A. Baldwin, Inorg. Chim. Acta, 1979, 36, 269. 254. T. Yamamoto, T. Kohara and A. Yamamoto, Chem. Lett., 1976, 1217. 255. M. Wada and K. Oguro, Inorg. Chem., 1976,15, 2346. 256. A. I. Borisova, L. P. Safronova, A. S. Medvedeva and N. S. Vyazankin, J. Gen. Chem. USSR (Engl Transl), 1978,48, 1857. 257. P. Binger and M. J. Doyle, J. Organomet. Chem., 1978,162, 195. 258. J. R. Blackborow, U. Feldhoff, F. W. Grevels, R. H. Grubbs and A. Miyashita, J. Organomet. Chem., 1979, 173, 253. 259. P. S. Braterman, J. Chem. Soc, Chem. Commun., 1979, 70. 260. R. Ceder, J. Granell, G. Muller, O. Rossell and J. Sales, J. Organomet. Chem., 1979, 174, 115. 261. M. Cusumano and V. Ricevuto, J. Chem. Soc, Dalton Trans., 1978, 1682. 262. G. Favero, A. Morvillo and A. Turco, Gazz. Chim. ItaL, 1979, 109, 27. 263. R. H. Grubbs and A. Miyashita, J. Am. Chem. Soc, 1978, 100, 7416. 264. R. H. Grubbs and A. Miyashita, J. Am. Chem. Soc, 1978,100, 7418. 265. H. Hoberg, V. Gotz and C. Kruger, J. Organomet. Chem., 1979,169, 219. 266. P. W. Jolly, C. Kruger, R. Salz and J. C. Sekutowski, J. Organomet. Chem., 1979,165, C39. 267. K. Kikukawa, T. Yamane, Y. Ohbe, M. Takagi and T. Matsuda, Bull. Chem. Soc. Jpn., 1979, 52, 1187. 268. K. J. Klabunde, B. B. Anderson and M. Bader, Inorg. Synth., 1979,19, 72. 269. C. Mealli, M. Peruzzini and P. Stoppioni, J. Organomet. Chem., 1980,192,437; C. Mealli and P. Stoppioni, J. Organomet. Chem., 1979,175, C19. 270. G. Longoni, M. Manassero and M. Sansoni, J. Organomet. Chem., 1979,174, C41. 271. Y. Nakamura, K. Maruya and T. Mizoroki, Nippon Kagaku Kaishi, 1978, 1486 (Chem. Abstr., 1979,90, 71 324). 272. K. Oguro, M. Wada and N. Sonoda, J. Organomet. Chem., 1979,165, C10. 273. K. Oguro, M. Wada and N. Sonoda, J. Organomet. Chem., 1979, 165, Cl 3. 274. M. Wada, S. I. Kanai, R. Maeda, M. Kinoshita and K. Oguro, Inorg. Chem., 1979,18, 417.

98 275. 276. 277. 278. 279. 280. 281. 282. 283. 284. 285. 286. 287. 288. 289. 290. 291. 292. 293. 294. 295. 296. 297. 298. 299. 300. 301. 302. 303. 304. 305. 306. 307. 308. 309. 310. 311. 312. 313. 314. 315. 316. 317. 318. 319. 320. 321. 322. 323. 324. 325. 326. 327. 328. 329. 330. 331. 332. 333. 334. 335. 336. 337. 338.

Nickel Hydride, Alkyl and Aryl Complexes D. Walther, E. Dinjus, W. Ihn and W. Schade, Z. Anorg. Allg. Chem., 1979,454, 11. T. Yamamoto, K. Igarashi, J. Ishizu and A. Yamamoto, J. Chem. Soc, Chem. Commun., 1979, 554. D. R. Fahey (Phillips Petrol. Co.), US Pat. 4 101 566 (1978) (Chem. Abstr., 1979,90,6538). D. R. Fahey and J. E. Mahan (Phillips Petrol. Co.), US Pat. 4 123 477 (1978) (Chem. Abstr., 1979, 90, 72 349). D. R. Fahey (Phillips Petrol. Co.), US Pat. 4 124 627 (1978) (Chem. Abstr., 1979, 90, 72 350). B. Akermark and A. Liungqvist, J. Organomet. Chem., 1978,149, 97. M. Almemark and B. Akermark, J. Chem. Soc, Chem. Commun., 1978, 66. H. P. Abicht and K. Issleib, J. Organomet. Chem., 1978,149, 209. A. Areas and P. Royo, Inorg. Chim. Ada, 1978, 31,97. A. Areas and P. Royo, An. Univ. Murcia Ciere 1972 (Publ. 1970), 1978, 31,61. F. Caballero and P. Royo, Synth. React. Inorg. Metal-Org. Chem., 1977,7,531; F. Caballero, M. Gomez and P. Royo, Transition Met. Chem., 1977, 2,130. G. Favero, A. Morvillo and A. Turco, / . Organomet. Chem., 1978,162, 99. G. Favero, M. Gaddi, A. Morvillo and A. Turco, J. Organomet. Chem., 1978,149, 395. A. Furlani, G. Polzonetti, M. V. Russo and G. Mattogno, Inorg. Chim. Ada, 1978, 26, L39. R. H. Grubbs and A. Miyashita, /. Chem. Soc, Chem. Commun., 1977, 864. R. H. Grubbs, A. Miyashita, M. Liu and P. Burk, J. Am. Chem. Soc, 1978,100, 2418. R. H. Grubbs and A. Miyashita, J. Am. Chem. Soc, 1978,100,1300. R. H. Grubbs and A. Miyashita, J. Organomet. Chem., 1978,161, 371. K. P. Healy and D. Pletcher, J. Organomet. Chem., 1978,161,109. H. Hoberg and J. Korff, J. Organomet. Chem., 1978,152, C39. K. Isobe, Y. Nakamura and S. Kawaguchi, Chem. Lett., 1977, 1383. W. Keim, F. H. Kowaldt, R. Goddard and C. Kruger, Angew. Chem., 1978, 90,493 (Angew. Chem., Int. Ed.Engl, 1978,17,466). K. J. Klabunde, B. B. Anderson, M. Bader and L. J. Radonovich, J. Am. Chem. Soc, 1978,100,1313; L. J. Radonovich, K. J. Klabunde, C. B. Behrens, D. P. McCollor and B. B. Anderson, Inorg. Chem., 1980, 19,1221. T. Kohara, T. Yamamoto and A. Yamamoto, /. Organomet. Chem., 1978,154, C37. K. Oguro, M. Wada and R. Okawara, /. Organomet. Chem., 1978,159,417. G. Sonnek and E. Dinjus, Z. Anorg. Allg. Chem., 1978,441, 58. K. Tamao, J. I. Yoshida, S. Okazaki and M. Kumada, Isr. J. Chem., 1976,15, 265. M. Wada, N. Asada and K. Oguro, Inorg. Chem., 1978,17, 2353. T. Yamamoto and A. Yamamoto, Chem. Lett., 1978, 615. T. Yamamoto, J. Chem. Soc, Chem. Commun., 1978, 1003. M. Anton, J. M. Coronas and J. Sales, J. Organomet. Chem., 1977,129, 249. E. Bartsch, E. Dinjus, R. Fischer and E. Uhlig, Z. Anorg. Allg. Chem., 1977, 433, 5. P. Binger, M. J. Doyle, J. McMeeking, C. Kruger and Y. H. Tsay, / . Organomet. Chem., 1977, 135, 405. F. Caballero and P. Royo, J. Organomet. Chem., 1977,137, 229. D. R. Fahey and J. E. Mahan, J. Am. Chem. Soc, 1977, 99, 2501. R. H. Grubbs, A. Miyashita, M. I. M. Liu and P. L. Burk, J. Am. Chem. Soc, 1977, 99, 3863. J. J. Habeeb and D. G. Tuck, J. Organomet. Chem., 1977,139, C17. R. D. Rieke, W. J. Wolf, N. Kujundzic and A. Kavaliunas, J. Am. Chem. Soc, 1977,99,4159; R. D. Rieke, Ace Chem. Res., 1977,10, 301. M. Wada, K. Kusabe and K. Oguro, Inorg. Chem., 1977,16,446. S. J. Tremont and R. G. Bergman, J. Organomet. Chem., 1977,140, C12. D. G. Morrell and J. K. Kochi, J. Am. Chem. Soc, 1975, 97, 7262. L. C. Sawkins, B. L. Shaw and B. L. Turtle, J. Chem. Soc, Dalton Trans., 1976, 2053. L. Cassar, S. Ferrara and M. Foa, Adv. Chem. Ser., 1974,132, 252. L. Cassar and M. Foa, J. Organomet. Chem., 1974, 74, 75. N. Kawata, T. Mizoroki, A. Ozaki and M. Ohkawara, Chem. Lett., 1973, 1165. D. R. Fahey (Phillips Petrol. Co.), US Pat. 3 800 000 (1974) (Chem. Abstr., 1974,81,42 059). L. Cassar, J. Organomet. Chem., 1973, 54, C57. P. K. Maples, M. Green and F. G. A. Stone, J. Chem. Soc, Dalton Trans., 1973, 388. P. S. Fitton and E. A. Rick (Union Carbide Corp.), US Pat. 3 674 825 (1972) (Chem. Abstr., 1972, 77, 88 664). U. Doring, Dissertation, Ruhr-Universitat Bochung, 1978. P. Binger, M. J. Doyle, C. Kruger and Y. H. Tsay, Z. Naturforsch., TeilB, 1979, 34, 1289. G. Longoni, P. Chini, F. Canziani and P. Fantucci, Chem. Commun., 1971, 470. R. J. Cross and R. Wardle, J. Chem. Soc. (A), 1970, 840. J. Chatt and B. L. Shaw, J. Chem. Soc, 1960, 1718. K. von Deuten, A. Beyer and R. Nast, Cryst. Struct. Commun., 1979,8, 755. J. E. Dobson, R. G. Miller and J. P. Wiggen, J. Am. Chem. Soc, 1971, 93, 554. R. G. Miller, R. D. Stauffer, D. R. Fahey and D. R. Parnell, J. Am. Chem. Soc, 1970,92, 1511. R. G. Miller and D. P. Kuhlman, J. Organomet. Chem., 1971, 26,401. E. Dinjus, I. Gorski, H. Matschiner, E. Uhlig and D. Walther, Z. Anorg. Allg. Chem., 1977,436, 39. T. Yamamoto, A. Yamamoto and S. Ikeda, J. Am. Chem. Soc, 1971, 93, 3350; ibid., 1971,93, 3360. R. H. Grubbs and A. Miyashita, Fundament. Res. Homogen. Cat., 1979, 3, 150. S. Takahashi, Y. Suzuki and N. Hagihara, Chem. Lett., 1974,1363; S. Takahashi, Y. Suzuki, K. Sonogashira and N. Hagihara, Chem. Lett., 1976, 515. S. Midollini, A. Orlandini and L. Sacconi, J. Organomet. Chem., 1978,162, 109. J. Ishizu, T. Yamamoto and A. Yamamoto, Chem. Lett., 1976,1091; T. Yamamoto, J. Ishizu, T. Kohara, S. Komiya and A. Yamamoto, J. Am. Chem. Soc, 1980,102, 3758.

Nickel Hydride,

Alky I and Aryl Complexes

99

339. W. Richter, Dissertation, Ruhr-Universitat Bochum, 1979; H. Hoberg and W. Richter, J. Organomet. Chem., 1980,195,355. 340. B. Akermark and A. Ljungqvist, J. Organomet. Chem., 1979,182, 59. 341. B. Akermark, H. Johansen, B. Roos and U. Wahlgren, J. Am. Chem. Soc, 1979,101, 5876. 342. E. Uhlig, B. Hipler and P. Miiller, Z. Anorg. Allg. Chem., 1978, 447, 18. 343. B. Biissemeier, P. W. Jolly and R. Salz, Abstr. 7th Int. Conf. Organomet. Chem., Venice, 1975, 184. 344. G. Miiller, U. Schubert, O. Orama and H. Schmidbaur, Chem. Ber., 1979,112, 3302. 345. G. Smith and J. K. Kochi, J. Organomet. Chem., 1980,198, 199. 346. L. M. Zubritskii, T. N. Famina, V. A. Kalinina and K. V. Balyan, J. Org. Chem. USSR (Engl. Transl.), 1979,15,2006. 347. H. Schmidbaur and H. J. Fuller (Hoechst AG.) Ger. Offen. 2 701 143 (1978) {Chem. Abstr., 1979, 90, 23 243). 348. H. Schmidbaur and O. Gasser (Hoechst AG.), Ger. Offen. 2 702 326 (1978) (Chem. Abstr., 1979, 90, 187 122). 349. R. Uson, J. Fornies, P. Espinet, R. Navarro, F. Martinez and M. Tomas, J. Chem. Soc, Chem. Commun., 1977,789. 350. A. K. Rappe and W. A. Goddard, J. Am. Chem. Soc, 1977, 99, 3966. 351. H. Schmidbaur, O. Gasser, C. Kruger and J. C. Sekutowski, Chem. Ber., 1977,110, 3517. 352. H. Schmidbaur, H. J. Fuller, V. Bejenke, A. Franck and G. Huttner, Chem. Ber., 1977,110, 3536. 353. A. Schott, H. Schott, G. Wilke, J. Brandt, H. Hoberg and E. G. Hoffmann, Liebigs Ann. Chem., 1973, 508. 354. H. Schmidbaur, G. Blaschke and H. P. Scherm, Chem. Ber., 1979,112, 3311. 355. H.Drevs, Z . C ^ m . , 1978,18,31. 356. E. Uhlig, B. Hipler and P. Miiller, Z. Anorg. Allg. Chem., 1978, 442, 11. 357. E. Uhlig and B. Hipler, Z. Chem., 1977, 17, 272. 358. H. Schmidbaur, G. Miiller, U. Schubert and O. Orama, Angew. Chem., 1978,90,126 (Angew. Chem., Int. Ed. Engl., 1978,17,126). 359. M. C. Barral, R. Jimenez, E. Royer, V. Moreno and A. Santos, Inorg. Chim. Acta, 1978, 31, 165. 360. B. Akermark, M. Almemark, J. Almlof, J. E. Backvall, B. Roos and A. Stdgard, J. Am. Chem. Soc, 1977, 99,4617. 361. B. T. Pennington and J. E. Howell, J. Organomet. Chem., 1977,136, 95. 362. R. Nast, Z. Naturforsch., Teil B, 1953, 8, 381. 363. E. Dinjus, B. Hipler and E. Uhlig, Z. Chem., 1975,15, 31. 364. K. J. Klabunde and T. O. Murdock, J. Org. Chem., 1979, 44, 3901. 365. H. Bonnemann, B. Bogdanovic, H. Schenkluhn, G. Wilke, C. Kruger and R. Mynott, in press (1980). 366. F. K. Schmidt, V. V. Saraev, G. M. Larin, V. G. Lipovich and L. V. Mironova, Bull. Acad. Sci. USSR, Div. Chem.Sci., 1974,2055. 367. S. D. Ittel and J. A. Ibers, Inorg. Chem., 1975,14,1183. 368. H. Brunner and W. Pieronczyk, Bull. Soc Chim. Belg., 1977, 86, 725. 369. C. A. Tolman and W. C. Seidel, J. Am. Chem. Soc, 1974, 96, 2774. 370. E. O. Fischer and A. Daweritz, Chem. Ber., 1978, 111, 3525. 371. D. J. Sepelak, C. G. Pierpont, E. K. Barefield, J. T. Budz and C. A. Poffenberger, J. Am. Chem. Soc, 1976, 98,6178. 372. H. Drevs, Z. Chem., 1976, 16, 493. 373. T. T. Tsou and J. K. Kochi, J. Am. Chem. Soc, 1979, 101, 6319. 374. T. T. Tsou and J. K. Kochi, J. Am. Chem. Soc, 1979,101, 7547. 375. R. Salz, Dissertation, Ruhr-Universitat Bochum, 1976. 376. L. Schieferstein, Dissertation, Ruhr-Universitat Bochum, 1978. 377. D. Walther, Z. Chem., 1977, 17, 348. 378. D. R. Fahey, J. Am. Chem. Soc, 1970, 92, 402. 379. C. Gosden, K. P. Healy and D. Pletcher, J. Chem. Soc, Dalton Trans., 1978, 972. 380. E. Dinjus, I. Gorski, E. Uhlig and H. Walther, Z. Anorg. Allg. Chem., 1976, 422, 75. 381. B. Corain, Gazz. Chim. Ital, 1974,104, 1279. 382. J. M. Bassett, J. R. Mandl and H. Schmidbaur, Chem. Ber., 1980, 113, 1145. 383. P. Rigo, M. Bressan and M. Basato, Inorg. Chem., 1979,18, 860. 384. R. Taube, N. Stansky and W. Hoboldt, Z. Chem., 1979,19, 412. 385. H. F. Klein, Angew. Chem., 1980, 92, 362 {Angew. Chem., Int. Ed. Engl., 1980,19, 362). 386. K. Isobe, Y. Nakamura and S. Kawaguchi, Bull. Chem. Soc. Jpn., 1980, 53, 139. 387. P. Carusi and A. Furlani, Gazz. Chim. Ital., 1980,110, 7. 388. W. Seidel and D. Geinitz, Z. Chem., 1979, 19, 413. 389. K. Sonogashira, K. Ohga, S. Takahashi and N. Hagihara, J. Organomet. Chem., 1980, 188, 237. 390. M. Svoboda and H. torn Dieck, J. Organomet. Chem., 1980, 191, 321. 391. D. R. Fahey and J. E. Mahan (Phillips Petrol. Co.), US Pat. 4 180 525 (1979). 392. J. M. Coronas, G. Muller, M. Rocamora and J. Sales, J. Organomet. Chem., 1980,184, 263. 393. K. P. McKinnon and B. O. West, Aust. J. Chem., 1968, 21, 2801. 394. T. Kohara, T. Yamamoto and A. Yamamoto, J. Organomet. Chem., 1980, 192, 265. 395. J. J. Eisch and J. E. Galle, J. Organomet. Chem., 1975, 96, C23. 396. M. Troupel, Y. Rollin, S. Sibille, J.-F. Fauvarque and J. Perichen, J. Chem. Res. (S), 1980, 24. 397. S. Sibille, M. Troupel, J.-F. Fauvarque and J. Perichen, J. Chem. Res. (S), 1980, 147. 398. R. Taube, U. Schmidt and H. Schwind, Z. Anorg. Allg. Chem., 1979, 458, 273. 399. G. Schiavan, G. Bontempelli, M. de Nobili and B. Corain, Inorg. Chim. Acta, 1980, 42, 211. 400. P. Eilbracht, U. Mayser and G. Tiedtke, Chem. Ber., 1980,113, 1420. 401. A. Emadand M. D. Rausch,7. Organomet. Chem., 1980, 191, 313. 402. R. Gompper and E. Bartmann, Liebigs Ann. Chem., 1980, 229.

100

Nickel Hydride,

Alky I and Aryl

Complexes

403. H. Lehmkuhl, A. Rufinska, R. Benn, G. Schroth and R. Mynott, J. Organomet. Chem., 1980,188, C36; LiebigsAnn. Chem., 1981, 317. 404. U. Hausig and K. Jonas, unpublished results, 1976; see also refs. 194, 413. 405. T. Kohara, S. Konuja, T. Yamamoto and A. Yamamoto, Chem. Lett., 1979, 1513. 406. J. D. McClure and K. W. Barnett, J. Organomet. Chem., 1974,80, 385. 407. R. Baker and M. G. Kelly, J. Chem. Soc, Chem. Commun., 1980, 307. 408. V. T. Aleksanyan, Y. M. Kimel'fel'd, R. B. Materikova and E. M. Smirnova, Zh. Fiz. Khim., 1980,54,663 {Chem. Abstr., 1980, 93, 70 295). 409. A. N. Nesmeyanov, L. S. Isaeva, G. I. Drogunova and L. N. Morozova, J. Organomet. Chem., 1980,195, C13. 410. F. K. Schmidt, L. V. Mironova, A. G. Proidakov, G. A. Kalabin, G. V. Ratovskii and T. V. Dimitrieva, Kinet. Catal. {Engl. Transl), 1978,19, 117. 411. W. Kalies, B. Witt and W. Gaube, Z. Chem., 1978, 20, 310. 412. A. V. Kavaliunas and R. D. Rieke, J. Am. Chem. Soc, 1980,102, 5944. 413. K. Jonas and C. Kriiger, Angew. Chem., 1980,92, 513 {Angew. Chem., Int. Ed. Engl., 1980,19, 520). 414. B. Hipler and E. Uhlig, J. Organomet. Chem., 1980,199, C27. 415. K. Jacob, K. H. Thiele, C. Geyer and G. Welde, Z. Anorg. Allg. Chem., 1980, 462,177. 416. E. Uhlig, G. Fehske and B. Nestler, Z. Anorg. Allg. Chem., 1980, 465,141. 417. E. Dinjus, D. Walther, R. Kirmse and J. Stach, J. Organomet. Chem., 1980,198, 215. 418. E. Sappa, A. Tiripicchio and M. Camellini, J. Organomet. Chem., 1980,199,243; A. Marinetti, E. Sappa, A. Tiripicchio and M. Camellini, Inorg. Chim. Ada, 1980, 44, LI 83. 419. A. N. Nesmeyanov, L. S. Isaeva, L. N. Morozova, P. V. Petrovskii, B. L. Tumanskii, B. V. Lokshin and Z. S. Klemenkova, Inorg. Chim. Acta, 1980, 43,1. 420. H. Hoberg and A. Herrera, Angew. Chem., 1980, 92, 951 {Angew. Chem., Int. Ed. Engl., 1980, 19, 927). 421. E. Carmona, F. Gonzalez, M. L. Poveda, J. L. Atwood and R. D. Rogers, J. Chem. Soc, Dalton Trans., 1980,2108. 422. M. Wada and Y. Koyama, J. Organomet. Chem., 1980, 201,477. 423. M. N. Bochkarov, L. P. Maiorova, S. E. Skobeleva and G. A. Razuvaev, Bull. Acad. Sci. USSR, Div. Chem. Sci., 1979,1717. 424. V. I. Nefedov, J. Salins and E. Uhlig, Koord. Khim., 1979, 5,1524. 425. G. Favero, J. Organomet. Chem., 1980, 202, 225.

Copyright © 1982 Elsevier Ltd.

Comprehensive Organometallic Chemistry