Chemistry of polynuclear metal complexes with bridging carbene or carbyne ligands. Part 82. Dimetallic compounds prepared from the complexes [MR2(η-C5H5)2](R = Cl or Bun; M = Ti or Zr)
Abstract
The bis(cyclopentadienyl)metal dihalides [MCl2(η-C5H5)2](M = Ti or Zr) are reduced by magnesium amalgam in tetrahydrofuran in the presence of the alkylidyne–tungsten complexes [W(CR)(CO)2(η-C5H5)](R = C6H4Me-4 or C6H4OMe-2) to afford the dimetal compounds [MW(µ-CR)(µ-σ:η2-CO)(CO)(η-C5H5)3]. Alternatively, the reagents [M(Bun)2(η-C5H5)2](M = Ti or Zr), prepared in situ in diethyl ether, react with the complexes [M′(CR)(CO)2(η-C5H5)](M = Ti, M′= W, R = C6H4Me-4 or C6H4OMe-2; M = Zr, M′= W, R = Me, C6H4Me-4,C6H4OMe-2, or C6H3Me2-2,6; M′= Mo, R = C6H4OMe-2) to give the compounds [MM′(µ-CR)(µ-σ:η2-CO)(CO)(η-C5H5)3] in high yield. The n.m.r. data for the new complexes are reported and discussed.