Reactions of heterometallic tungsten-iridium and tungsten-rhodium complexes containing C-4 chains

Modified syntheses of {Cp(OC)(3)W}C=CC=C{M(CO)(PPh3)(2)} (M = Rh, Ir) from W(C=CC=CH)(CO)(3)Cp and M(OTf)(CO)(PPh3)(2) are described. The Group 9 meta l centre is the most electron-rich site, readily adding Met or C-2(CN)(4). Reactions with iron carbonyls give successively {Cp(OC)(3)W}C=CC2 {Fe2M(CO) (8)(PPh3)} and {Cp(OC)(8)Fe2W)C2C2{Fe2M(CO)(8)(PPh3)}, in which Fe,(CO), mo ieties add to a C=C group and the adjacent metal centre. X-ray structures o f {Cp(OC)(3)W}C=CC=C{Rh(CO)[eta-C-2(CN)(4)](PPh3)(2)}, {Cp(OC)(3)W}C=CC2{Fe 2Rh(CO)(8)(PPh3)} and {Cp(OC)(8)Fe2W}C2C2 (Fe2Ir(CO)(8)(PPh3)} have been de termined. (C) 2000 Elsevier Science S.A. All rights reserved.