Some complexes containing carbon chains end-capped by M(CO)2Tp′ [M = Mo, W; Tp′ = HB(pz)3, HB(dmpz)3] groups

Complexes M( CC CSiMe3)(CO)(2)Tp' (Tp' = Tp [HB(pz)(3)], M = Mo 2, W 4; Tp' = Tp* [HB(dmpz)(3)], M = Mo 3) are obtained from M( CC CSiMe3)(O2CCF3)(CO)(2)(tmeda) (1) and K[Tp']. Reactions of 2 or 4 with AuCl(PPh3)/K2CO3 in MeOH afforded M{ CC CAu(PPh3)}(CO)(2)Tp' (M = Mo 5, W 6) containing C-3 chains linking the Group 6 metal and gold centres. In turn, the gold complexes react with Co-3(mu(3)-CBr)(mu-dppm)(CO)(7) to give the C-4-bridged {Tp(OC)(2)M} CC CC {Co-3(mu-dppm)(CO)(7)} (M = Mo 7, W 8), while Mo( CBr)(CO)(2)Tp* and Co-3{mu(3)-C(C C)(2)Au(PPh3)}(mu-dppm)(CO)(7) give {Tp*(OC)(2)Mo} C(C C)(2)C {Co-3(mu-dppm)(CO)(7)} (9) via a phosphine-gold(I) halide elimination reaction. The C-3 complexes Tp'(OC)(2)M CC CRu(dppe)Cp* (Tp'= Tp, M = Mo 10, W 11; Tp' = Tp*, M = Mo 12) were obtained from 2-4 and RuCl(dppe)Cp* via KF-induced metalla-desilylation reactions. Reactions between Mo( CBr)(CO)(2)Tp* and Ru{(C C)(n)Au(PPh3)}(dppe)Cp* (n = 2, 3) afforded {Tp*(OC)(2)Mo} C(C C)(n)- {Ru(dppe)Cp*} (n = 2 13, 3 14), containing C-5 and C-7 chains, respectively. Single-crystal X-ray structure determinations of 1, 2, 7, 8, 9 and 12 are reported. (c) 2006 Elsevier B.V. All rights reserved.