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Activation of carbon disulphide by metal carbonyl anions: Formation of trithiocarbonate complexes
C50
Journal of Organometallic Chemishy. @ Ekevier Sequoia S-A.. Lausanne -
communication
Preliminary
ACTIVATION FORMATION
OF CARBON DISULZHIDE OF TRiTHTOCARBONATE
JAMES HUNT, SELBY A.R. KNOX* Department
80 (1974) C5O-C52 Printed in The Netherlands
of lnorganrc
Chemistry,
BY METAL COMPLEXES
and VALERiE The Universrty.
CARBONYL
ANIONS:
OLtPHANT Bristol,
BS8
ITS
(Great
Bntain)
(Received September 6th, 1974)
Summary complexes are formed when metal carbonyl anions are carbon disulphide and a neutralistng agent such as methyl iodide or Re(CO)S Br. Trithiocarbcnate treated consecutively
wth
Although activation of carbon disulphide by transition metal compleses is an area much studied of late (and recently reviewed [l] for the first time), no
reports have appeared of attempts to directly exploit the electrophilic reactivity of carbon in the molecule. Nucleophiles SUC!Ias cyanide ion do attack CS? at carbon [ 21, and it seemed likely that transition metal carbonyl anions might act simi.ia.rly. We describe here such reactions, which unexpectedly provide trithiocarbonate complexes. Treatment of tetrahydrofuran solutions of the sodium salts of [M(CO), ](M = Mn, Re) with excess CSz for 1 h, followed by methylation with methyl iodide, gave (5-1070) tnthlocarbonate complexes M(C0)3SpC(SMe) (I; M = Mn, Re); for I (M = Re) m-p. 93”; v(C0) (hexane) 2109m, 2014s, 19999, 1963s cm-’ ; T 7.42s: m/e (111- nCO)+ (n = O-3). Analogous products Fe(CO)(C,H,)S,C(SMe) [3] and Mo(CO)~(C~H~)S~C(SM~) [4] were obtained from [Fe(C0)2(CjHS)]and [ Mo( CO),( Cj H5 ) ]- respectively. The reaction of [Re(CO), ]- with CS2/MeI also gave small amounts of a yellow crystalline complex (CO)AReS2CSRe(CO), (m.p. 135-140” (dec.); v(C0) (hexane) 2147w, 2103m, 2046s, 2005s, 1992s, 1955s cm-’ ; m/e (AZ- nCO)+ (n = O-9)). A trithiocarbonate-bridged structure II (M’ = MZ = Re) is strongly indicated by the carbonyl IR spectrum, which is composed of bands typical of both the (CO)dReSzC (2103m, 2005s, 1992s, 1955s cm-’ ) and (CO)sReS (2147w, 2046s, 1992s cm-‘) structural units, by comparison with the spectra of I (M = Re) and III respectively. The apparent structural relationship of I (M = Re) and II (M’ = M’ = Re) led us to treat [Re( CO), ]- with CSI and Re(CO), Br consecutively in the hope of
c51
0
P
I /--+y
OC\
I I ‘CO
MZ/=O
oc,Ij\s,~C-sMe :
E,
(I)
0
C
OC-Fe-
\/ /\
Oc
0
Co SAC\SMe C 0
(III)
c
l--O _
\/
/K_
OC-MM-S
A OC
;
occ? \ s-Re-co A
C 0
0”
/I
C 0
(ix)
forming the dirhenium complex. That this reaction yielded II (M’ = M’ = Re) readily (45%) provides further support for the structural assignment. Only IR spectroscopic evidence was obtained for formation of (CO),MnS,CSMn(CO)j (II; M’ = M’ = Mn) by a similar route. Mixed metal analogues are obtained, however, if either [Mn(CO), ]- or [Re(CO), ]- isallowed to react with CS,, and is subsequently treated with Re(CO),Br or Mn(CO)SBr. respectively. The major product Mn, M’ = Re), with minor formation of II (M’ = Re, (5%) in each case is II (M’ = M’ = Mn), suggesting that each reaction sequence involves a common mtermediate. Most likely is (CO)5 ReSC(S)SMn(CO)j (IV) which would be expected to form II (M’ = Mn, M” = Re) preferentially on CO elimination. Another example of this tendency towards trithiocarbonate formation has been presented in the very recent report [ 5] of the determination of the molecular structure of [(CO).,ReS,CSRe(CO)d lz, prepared from Re(CFa)(CO), and CS,. It is interesting that this complex can be envisaged as arising from dimerisation of (CO), ReS,CSRe(CO), , with sulphur bridge formation and CO elimination, though we have not yet established that this can occur. A complex (PPh,)(NO)NiSzCSNi(PPh3)2(NO), apparently related to II, has been prepared [6] from CS,‘- and Ni(I)(PPh,),(NO), but it was not possible for us to obtain II (,&I’ = M’ = Mn or Re) by a similar route. The activation by metal carbonyl anions of other molecules (e.g. COz and RNCS) containing electrophilic carbon atoms, and the process by which trithiocarbonate complexes are formed from CS, in the reactlons described here, are under investigation. it is noteworthy to record in connection with the latter that addition of sulphur to the [Re(CO)s ]-/CSI/Mei reaction, prior to Mel addition, serves to promote formation (9%) of Re(CO),SC(S)(SMe) (III) { m.p. 83”; v(C0) (hexane) 214Ow, 2038s, 1991s cm-’ ; ‘i- 7.27s; m/e (AZ - nCO)+ (n = O-4)) over I (M = Re) (5%).
c52
References 1 2 3 4 5 6
LS. Butler and kE. Fenster. J. Organometal. Chem.. 66 (1974) 161. G. 8Shr. Angew. Chem.. 70 (1958) 606. ft. Bruce and G.R. Knox. J. OrganometaL Chem.. 6 (1966) 67. R. Havlin and G.R. Knox. Z Nahu-forxb. B. 21 (1966) 1108. G. ‘l7ueIe. G. Liehr and E. Lindner. J. Organomet.aL Cbem.. 70 (1974) H. Brunner. 2. Naturforsch. B. 24 (1969) 275.
427
Journal of Organometallic Chemishy. @ Ekevier Sequoia S-A.. Lausanne -
communication
Preliminary
ACTIVATION FORMATION
OF CARBON DISULZHIDE OF TRiTHTOCARBONATE
JAMES HUNT, SELBY A.R. KNOX* Department
80 (1974) C5O-C52 Printed in The Netherlands
of lnorganrc
Chemistry,
BY METAL COMPLEXES
and VALERiE The Universrty.
CARBONYL
ANIONS:
OLtPHANT Bristol,
BS8
ITS
(Great
Bntain)
(Received September 6th, 1974)
Summary complexes are formed when metal carbonyl anions are carbon disulphide and a neutralistng agent such as methyl iodide or Re(CO)S Br. Trithiocarbcnate treated consecutively
wth
Although activation of carbon disulphide by transition metal compleses is an area much studied of late (and recently reviewed [l] for the first time), no
reports have appeared of attempts to directly exploit the electrophilic reactivity of carbon in the molecule. Nucleophiles SUC!Ias cyanide ion do attack CS? at carbon [ 21, and it seemed likely that transition metal carbonyl anions might act simi.ia.rly. We describe here such reactions, which unexpectedly provide trithiocarbonate complexes. Treatment of tetrahydrofuran solutions of the sodium salts of [M(CO), ](M = Mn, Re) with excess CSz for 1 h, followed by methylation with methyl iodide, gave (5-1070) tnthlocarbonate complexes M(C0)3SpC(SMe) (I; M = Mn, Re); for I (M = Re) m-p. 93”; v(C0) (hexane) 2109m, 2014s, 19999, 1963s cm-’ ; T 7.42s: m/e (111- nCO)+ (n = O-3). Analogous products Fe(CO)(C,H,)S,C(SMe) [3] and Mo(CO)~(C~H~)S~C(SM~) [4] were obtained from [Fe(C0)2(CjHS)]and [ Mo( CO),( Cj H5 ) ]- respectively. The reaction of [Re(CO), ]- with CS2/MeI also gave small amounts of a yellow crystalline complex (CO)AReS2CSRe(CO), (m.p. 135-140” (dec.); v(C0) (hexane) 2147w, 2103m, 2046s, 2005s, 1992s, 1955s cm-’ ; m/e (AZ- nCO)+ (n = O-9)). A trithiocarbonate-bridged structure II (M’ = MZ = Re) is strongly indicated by the carbonyl IR spectrum, which is composed of bands typical of both the (CO)dReSzC (2103m, 2005s, 1992s, 1955s cm-’ ) and (CO)sReS (2147w, 2046s, 1992s cm-‘) structural units, by comparison with the spectra of I (M = Re) and III respectively. The apparent structural relationship of I (M = Re) and II (M’ = M’ = Re) led us to treat [Re( CO), ]- with CSI and Re(CO), Br consecutively in the hope of
c51
0
P
I /--+y
OC\
I I ‘CO
MZ/=O
oc,Ij\s,~C-sMe :
E,
(I)
0
C
OC-Fe-
\/ /\
Oc
0
Co SAC\SMe C 0
(III)
c
l--O _
\/
/K_
OC-MM-S
A OC
;
occ? \ s-Re-co A
C 0
0”
/I
C 0
(ix)
forming the dirhenium complex. That this reaction yielded II (M’ = M’ = Re) readily (45%) provides further support for the structural assignment. Only IR spectroscopic evidence was obtained for formation of (CO),MnS,CSMn(CO)j (II; M’ = M’ = Mn) by a similar route. Mixed metal analogues are obtained, however, if either [Mn(CO), ]- or [Re(CO), ]- isallowed to react with CS,, and is subsequently treated with Re(CO),Br or Mn(CO)SBr. respectively. The major product Mn, M’ = Re), with minor formation of II (M’ = Re, (5%) in each case is II (M’ = M’ = Mn), suggesting that each reaction sequence involves a common mtermediate. Most likely is (CO)5 ReSC(S)SMn(CO)j (IV) which would be expected to form II (M’ = Mn, M” = Re) preferentially on CO elimination. Another example of this tendency towards trithiocarbonate formation has been presented in the very recent report [ 5] of the determination of the molecular structure of [(CO).,ReS,CSRe(CO)d lz, prepared from Re(CFa)(CO), and CS,. It is interesting that this complex can be envisaged as arising from dimerisation of (CO), ReS,CSRe(CO), , with sulphur bridge formation and CO elimination, though we have not yet established that this can occur. A complex (PPh,)(NO)NiSzCSNi(PPh3)2(NO), apparently related to II, has been prepared [6] from CS,‘- and Ni(I)(PPh,),(NO), but it was not possible for us to obtain II (,&I’ = M’ = Mn or Re) by a similar route. The activation by metal carbonyl anions of other molecules (e.g. COz and RNCS) containing electrophilic carbon atoms, and the process by which trithiocarbonate complexes are formed from CS, in the reactlons described here, are under investigation. it is noteworthy to record in connection with the latter that addition of sulphur to the [Re(CO)s ]-/CSI/Mei reaction, prior to Mel addition, serves to promote formation (9%) of Re(CO),SC(S)(SMe) (III) { m.p. 83”; v(C0) (hexane) 214Ow, 2038s, 1991s cm-’ ; ‘i- 7.27s; m/e (AZ - nCO)+ (n = O-4)) over I (M = Re) (5%).
c52
References 1 2 3 4 5 6
LS. Butler and kE. Fenster. J. Organometal. Chem.. 66 (1974) 161. G. 8Shr. Angew. Chem.. 70 (1958) 606. ft. Bruce and G.R. Knox. J. OrganometaL Chem.. 6 (1966) 67. R. Havlin and G.R. Knox. Z Nahu-forxb. B. 21 (1966) 1108. G. ‘l7ueIe. G. Liehr and E. Lindner. J. Organomet.aL Cbem.. 70 (1974) H. Brunner. 2. Naturforsch. B. 24 (1969) 275.
427