Chemistry of polynuclear metal complexes with bridging carbene or carbyne ligands. Part 67. Reactions of the salts [X][W(CR)(CO)2(η5-C2B9H9Me2)][X = P(CH2Ph)Ph3, R = C6H4Me-4; X = NEt4, R = Ph] with bis(cyclo-octa-1,5-diene)platinum

The salts [X][W(CR)(CO)2(η5-C2B9H9Me2)][X = NEt4, R = Ph; X = P(CH2Ph)Ph3 or PPh4, R = C6H4Me-4] have been prepared, and an X-ray diffraction study has been carried out on the tetraphenylphosphonium compound. There are two very similar crystallographically independent anions, together with their associated counter ions, in the asymmetric unit of the structure. In the anion the tungsten atom carries two terminally bound carbonyl ligands (W–CO mean 2.019 A, W–C–O mean 176.9°), a p-tolylmethylidyne ligand [WCC6H4Me-4 mean 1.83(3)A], and the η5-7,8-C2B9H9Me2 cage [mean W–ligated cage atoms, 2.424 A(mean of 10)]. Treatment of the species [X][W(CR)(CO)2(η5-C2B9H9Me2)][X = P(CH2Ph)Ph3, R = C6H4Me-4; X = NEt4, R = Ph] in thf (tetrahydrofuran) with [Pt(cod)2](cod = cyclo-octa-1,5-diene) affords the complexes [P(CH2Ph)Ph3][PtW(µ-CC6H4Me-4)(CO)2(cod)(η5-C2B9H9Me2)](2a) and [NEt4][PtW(µ-CPh)(CO)2(cod)(η5-C2B9H9Me2)](2b), respectively. The cod ligand in the compounds (2) may be displaced with tertiary phosphines, but crystalline products were not obtained. Moreover, protonation of (2) led to decomposition. However, treatment of (2a) with [AuCl(PPh3)] and TIPF6, and (2b) with the gold reagent and KPF6, in thf, affords the trimetal compounds [AuPtW(µ3-CR)(CO)2(PPh3)(cod)(η5-C2B9H9Me2)](R = C6H4Me-4 or Ph), which were fully characterised. The n.m.r. data (1H, 13C-{1H}, 195Pt-{1H}, and 31P-{1H}) for the complexes are reported.