Chemistry of polynuclear metal complexes with bridging carbene or carbyne ligands. Part 72. Di- and tri-metal compounds prepared from the alkylidyne tungsten complexes [W(CR)(CO)3{H2B(pz)2}][R = C6H4Me-4 or Me, H2B(pz)2= dihydrobis(pyrazol-1-yl)borate]

The alkylidynetungsten compounds [W(CR)(CO)3{H2B(pz)2}][R = C6H4Me-4 or Me, H2B(pz)2= dihydrobis(pyrazol-1-yl)borate] have been prepared, and used to prepare several complexes containing bonds between tungsten and other transition elements. Thus the compounds [Co2W(µ3-CC6H4Me-4)(CO)9{H2B(pz)2}], [Rh2W(µ3-CMe)(µ-CO)(CO)3(η5-C9H7)2{H2B(pz)2}](η5-C9H7= indenyl), [FeW(µ-CC6H4Me-4)(CO)6{H2B(pz)2}], [PtW(µ-CC6H4Me-4)(CO)3(cod){H2B(pz)2}](cod = cyclo-octa-1,5-diene), and [MW2(µ-CR)2(CO)6{H2B(pz)2}2](M = Ni or Pt, R = C6H4Me-4; M = Pt, R = Me) have been synthesised by treating the appropriate alkylidynetungsten compound with [Co2(CO)8], [Rh(CO)2(η5-C9H7)], [Fe2(CO)9], or [M(cod)2](M = Ni or Pt), respectively. The unsaturated dimetal compound [FeW(µ-CC6H4Me-4)(CO)6{H2B(pz)2}] reacts with dppm (Ph2PCH2PPh2), RCCR (R = Me or Ph), and CH2N2 to afford the complexes [FeW(µ-CC6H4Me-4)(µ-CO)(µ-dppm)(CO)3{H2B(pz)2}], [FeW{µ-C(C6H4Me-4)C(R)C(R)}(CO)6{H2B(pz)2}], and [FeW{µ-trans-CHC(H)C6H4Me-4}(µ-CO)(CO)6{H2B(pz)2}], respectively. N.m.r. data (1H, 13C-{1H}, 31P-{1H}, or 195Pt-{1H}) for the new compounds are reported and discussed in relation to the structures proposed.