Reactions of transition metal σ-acetylide complexes

C40 Journal

of Organometallic

Elsevier

Sequoia

Preliminary

S.A.,

Chemistry,

Lausanne

295 (I 985) C4WC4.1

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REACTIONS

OF TRANSITION

METAL

o-ACETYLIDE

COMPLEXES

III*. SYNTHESIS OF SOME ARYLDIAZOVINYLIDENE AND CYCLOHEPTATRIENYLVINYLIDENE COMPLEXES. X-RAY STRUCTURES OF [Ru(C=CPhN=NC,H3Mez-3,4)(PPh,),(r7-CSH5)] [BF,] = U.67CH2C?2 AND [Ru,C=CPh(C7H,);~(DPPE)(qC,H,)] [PF,] * 0.63CH,c’l,

MICHAEL I. BRUCE*, CHRISTOPHER and GEORGE A, KOUTSANTONIS

DEAN.

D. NEIL

Jordan Laboratories, Lkpartment of Physical and Inorganic Adelaide, Adelaide, South A:r
July

29th.

DUF’FY,

MARK

Chemistq.

G

HUMPHREY

The lYniversrt> of‘

1985)

Summary Addition of arenediazonium (L, = (PPh,), or DPPE) gives cycloheptatrienylvinylidene the title complexes confirm C=C distances are 1.823(g) 1.84819) and 1..32(1 k A for

or tropylium salts to Ru(C,Ph)(L),(v-C,H,) the corresponding cationic aryldiazovinylidene and complexes, respectively; the X-ray structures of the presence of the new ligands. The Ru-C and and 1.34(3.) a for the ‘aryldiazo complex. and the E.:ycloheptatrienyl derivative.

The most commonly used methods for t,he synthesis of transition metal complexes containing vinylidene ligands are by direct reaction of I-alkynes with a suitable metal substrate, or by protonation or alkylation of a metal acetylide complex [ 11 . Electrophilic addition to the d-carbon of the acetylide ligand has been extensively studied with reagents such as HBFr, or HPF, [2], [R,O] [BF,] (R = Me or Et) or FS03Me [2,3] and with alkyl halides [i-r]. Double addition of an eleetrophile has been reported in the successive react,ions of [W(C,But)(CO),]with FSO,Me or [Et,O]” followed by CFJSO& 151. and the addition of reactive metal hydrides to metal acetylides has given binuclear complexes with p-viiiylidene ligands [ 61 . Seeking to extend the range of known vinylidene ligands, we have studied the reactions of two classes of cationic organic reagents, arenediazonium and *t-or

Part

If.

see ref.

0022-328X3/85/$03.30

12

f

1985 Elsevier

Sequoia

S.A.

c41

tropylium salts. Addition of [ArN,] [BF4] to solutions of Ru(C2Ph)(PPha),(n-CgH5) (la) in THF readily affords the corresponding aryldiazovinylidene complexes [Ru(C=CPhN=NAr)(PPh,),(77C,H,)] [BF4] (2), which are isolated as bright red, air stable crystalline solids. The IR spectra contain bands at ca. 1550 cm-’ which can be assigned to v(C=C) + Y(N=N). In the NMR spectra, the expected resonances are found, with the characteristic low-field triplet (J(CP) 15.8 Hz) of the metal-bonded vinylidene a-carbon occurring at 6 362 ppm in the PhNz derivative. Similarly, the reaction between Ru(C,Ph)(DPPE)(q-CgH5) (lb) and [C,H,] [PF6] gave [Ru{C=CPh(C,H,)}(DPPE)(v-C5H5)] [PF,] (3) as a rose-pink powder. The ‘H NMR spectrum contains multiplets at 6 2.85, 5.34,6.28 and 6.53 ppm (relative intensities l/2/2/2), which are assigned to the protons attached to the C, ring, indicating the presence of a cycloheptatrienyl group; a triplet at 6 347 ppm in the 13C NMR spectrum in the analogous PPh3 complex confirmed their formulation as substituted vinylidene complexes.

+

Ru - C =c L

Ph / \

/ I

N=N \ Ar

Ru-CCC-_-h

L’ (la) L = PPh3 (lb) L2 = dppe -

Ar = Ph, C6H3Me2-3,4, C6H4N02-4,

(2) L = PPh3

0\ ci L/Ru-

c =

I

L

(2) L2 = dwe

C6H3C12-2,4, C6H40Me-4

We have fully characterised these novel ligands by single-crystal X-ray studies of the title complexes. Suitable crystals were grown from dichloromethane/ methanol (2) and dichloromethane/ethanol mixtures (3). Diffraction data for both complexes were collected on an Enraf-Nonius CAD 4 four-circle diffractometer using graphite-monochromated MO-K, radiation, X(Mo-K,) 0.7107 A. Crystal data: C5,HJ9BF4NZPZRu - 0.67CHzC12 (2), M = 1069.33, monoclinic, space group P2,/n; a 22.424(6), b 10.215(5), c 23.292(7) A, p 104.64(2)“, U 5160 A3; D, 1.37, D, = 1.37 g cm -3 for 2 = 4; F(OOO) 2196 electrons, ~(MoK, ) 4.44 cm-‘. T = 293 K. C46H41F6P3R~ - 0.63CHzC12 (3), M = 955.4, triclinic, space group Pi; a 11.67(3), b 12.10(3), c 15.98(4) A, (Y76.6(2), fl 88.3(l), y 86.8(l)“, U 2191(8) A3;Dc 1.45 g cme3 for 2 = 2; F(OOO) 972.9 electrons, ~(Mo-K,) = 5.56 cm-‘. T= 293 K.

c42

For 2, 4451 unique data (for 3, 3809) were collected in the range 1.2 < B < 21” (1.3 < 0 < al”), of which 2847 (3432) with J > 2.5~~(!) were refined to R = 0.046, R, =0.049(R = 0.059, R, = 0.069). Both structures were solved by obtaining the coordinates of the Ru atom from a Patterson map; all other non-hydrogen atoms were revealed in subsequent refinement and Fourier difference maps [ 71. Neutral atom scattering factors were ohtamed from refcrence [S] . Bot.h structures contain dichloromethane of crystallisation, the site occupancies of which were refined to 0.67 and 0.63 of a molr:~~& for 2 and 3, respectively. The BF, amon in 2 was disordered, satisfactory refinement being obtained using a model wit.h three orientations with site occupancies of 0.65. 0.25 and 0.10. For 2, all non.-hydrogen atoms except phenyX group carbons and fluorines had anisotropic thermal parameters; for 3. c)dy the phenyl carbons of the non-hydrogen atoms had isotropic thermal parameters. In the finai cycles of the blocked-rnat,rix least squares refinemen: 1 ~hp phpny/ al-;t~ ,._. -66. r-

Fig. 1. PLUTO numbering Ru(l)-C(42) 1.27(l),

plot

scheme.

1.823(g), N(2)-<(50)

P(2)-Ru(l)---C(42) C(43)FNtl)

of

cation in ERu(C=CPbN:NC6H,Me,-3,4)(PPh,),(ll-C,H,)l

Bond

distances: C(42)-&X43)

1.42(I) 69.7(3),

114.4(8),

Ru(l)--C(cp)

C(43)--h

A:

1.34(l),

bond

angles:

(a~.)

C(43)--6(44) P(l)-

Ru(lj--C(42)-~C(43) ‘(1)

--N(2)

2.28,

114.9(7),

-Ru(l) 169.9(7),

LBF,l

Ru(l)--P(l) 1.48(l), -P(2) C(42)

N(l)--K(Z)--C(W)

2.362(3), C(43f-~N(l)

98.8(l).

P(l)---Ru(l)

-C(43)--Cc441 ! i3.Orq”.

(2). Ku(1

showing J-~P(~)

1.42(l), C(42f 221.Ai8).

atom 2.360(3),

N(l)--N(Z) 36.1(3). q42)-

c43 CL6

c4 Fig.

2. PLUTO

scheme. C(33)

Bond

plot

1.848(g),

in [Ru

83.9(l),

174.9(6),

{C=CPh(C,H,))(DPPE)(+C,H,)I

Ru(l)-C(cp)

C(33)-C(34)

P(l)_Ru(l~P(2) C(34)

of cation

distances:

(a~.)

1.32(l),

2.26,

C(34)-C(27)

P(l)-Ru(l)-C(33)

C(33)-C(34)-C(27)

2.298(2),

1.483(g), 81.6(Z),

121.1(6).

[PF6]

Ru(l)-P(1)

C(34)*(35)

showing

atom

numbering

2.305(2).

1.55(l)

P(2)-Ru(l)-C(33)

C(33)-C(34)--c(35)

(3).

Ru(l)-P(2) 95.8(2).

!I;

bond

Ru(l)angles:

Ru(l)-C(33)-

118.1(7)‘.

cyclopentadienyl rings were included as rigid groups (C-C 1.395 and 1.42 A respectively) and the hydrogen atoms were placed in calculated positions (C-H 1.08 A) with a common thermal parameter. The structures of the cations of 2 and 3 are illustrated in Figs. 1 and 2, respectively, which also give some selected bond distances and angles*. Both cations are of the now familiar, nearly octahedral RuLPz(n-CSHS) structural type, and contain disubstituted vinylidene ligands. The Ru-C distances (1.823(g) W in 2,1.848(g) A in 3) are considerably shorter than that expected for an Ru-C(sp) single bond; indeed, comparison with the Ru-CO distance recently determined [9] in [Ru(CO)(PPh,),(nC,H,)1 [BPh4] indicates an even greater degree of backbonding from the metal into the vinylidene n* orbitals. Both the Ru-C and the C=C distances of the vinylidene ligand *The

atomic

coordinates

Crystallographic (England).

Any

Data request

for

this

Centre, should

work

are available

University

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be accompanied

on request Laboratory,

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Cambridge

Cambridge

for this

CB2

1EW

ConUIIUnicatiOn.

c44

(1.34(l) ii in 2, 1.32(l) .$ in 3) are comparable wit.h those found previously in [Ru(C=CHMe)(PMe,)2(q-C,H,)I [PF,] (1.845(7) and 1.313(10) :I, respectively) [lo]. The Ru-C--C system is nearly linear (RuC(42)6(43) 1.69.9(7)’ in 2, RuC(33)C(34) 174.9(G)’ jn 3). In 2, the phenyldiazo group adopts the usual trans configuration, the N--N and N--C parameters not. differing significantly from those found for transazobenzene [ll] . In 3, the C, ring has the tub conformation: of interest is the calculated location of the hydrogen atom attached to C(35). t.he C-H bond being directed towards the centre of a Ph group of 11~~” DPPE ligand.

i,)

The reactivity of these new complexes has been investigated briefly. Reaction with anionic nucleophiles (Ii-, Me-, OMe-) results in displacement of the addend and regeneration of the neutral phenylacetylide complexes. The diazo function in 2 exhibits a remarkable tendency to bind to electrophiles such as H’ or Me+; the dicationic [Ru(C=CPhNMe=NPh)(PPhJ)z(r~-CiH~j] ‘A and tric,ationic complexes resulting from such reac[Ru(C=CPhNH=NHPh)(PPh&(p-C,H,)1’+ tions have been identified so far, Not, surprisingly, reacton with MnMe( GOiS affords the cyclometallated derivative 4. Full dct,ails of I.hese and related cornplexes will be given elsewhere. Acknowledgements. We thank Dr M.R. Snow for access to the X-ray diffractometer, Dr E. Horn for collecting the data set for complex 2, and the Australian Research Grants Scheme for financial support. CD and MGH are Commonwealth Post-Graduate Research awardees:. References 1

M.I. Bruce

2 M.I. 3 A.

Bruce Davison

8

A.G.

Swincer,

R.C.

Wallis,

and

J.P.

Selegue,

Adv.

Organomet.

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Chem.

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22 (1984) (1978) (1978)

59.

Cl. 7763.

Davies and P. Warner, J, Organomet. Chem., 246 (1983) C65. A. Mayr. K.C. Schaefer and E.Y. Hung, J. Am. Chem. Sot., 106 (1984) 1517. D. Afzal, P.G. Lenhert and C.M. Lukehart. J. Am. Chem. Sot.. 106 (1984) 30.50. Programmes used in these structure determinations were: SUSCAD, Data reduction program for CAD4 diffractometer, J.M. Guss, IJniversity of Sydney, 1979; ABSORB. Program for absorption correction, J.M. Gus, University of Sydney. 1980; SHELX. Programme for crystal structure determination, G.M. Sheldrick, University of Cambridge. 1976: PLUT078, Flatting programme for molecular structures, W.D.S. Motherwell, lrniversity of Cambridge, 1978. J.A. Ibers and W.C. Hamilton, ecb, International Tables for X-IX? Crystallography. K>,nnch Press,

4 S. Abbott,

5 6 7

and and

Birmingham, 9 J.M.

Wisner,

S.G.

1974, T.J.

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Bruce. F.S. Wong, B.W. Skelton and A.H. White, d. Chem. Sot.. Dalton Trans.. (1 982) 2203. 11 C.J. Brown, Acta Crystallogr.. 21 (1966) 146. 12 M.I. Bruce. T.W. Hamblv, M.I< Snow and A.G. Saincrr. OrgwometaIlic~, 4 (1985) 501, 10

M.I.