Chemistry of polynuclear metal complexes with bridging carbene or carbyne ligands. Part 80. Mixed-metal tungsten and ruthenium compounds

Abstract

Treatment of the compounds [W(CC6H4Me-4)(CO)2L]{L =η-C5H5 or HB (pz)3[hydrotris(pyrazol-1-yl)borate]} with a three-fold excess of [Ru(CO)4(η-C2H4)] in light petroleum affords as the only products the tetranuclear metal cluster complexes [WRu3(µ3-CC6H4Me-4)(CO)11L]. In contrast, a similar reaction (L =η-C5H5) employing a W : Ru mol ratio of 2:1 gives in high yield the trinuclear metal complex [W2Ru{µ3-C2(C6H4Me-4)2}(CO)7(η-C5H5)2], which in refluxing cyclohexane releases CO and affords the electronically unsaturated species [W2Ru(µ-CC6H4Me-4)(µ3-CC6H4Me-4)(CO)5(η-C5H5)2]. With hydrogen and with diazomethane the latter compound affords the complexes [W2RuH(µ-H)(µ-CC6H4Me-4)(µ3-CC6H4Me-4)(CO)4(η-C5H5)2] and [W2Ru(µ-CH2)(µ-CH2)(µ-CC6H4Me-4)(µ3-CC6H4Me-4)(CO)4(η-C5H5)2], respectively, whereas alkynes yield the species [W2Ru(µ-CC6H4Me-4)(µ3-CC6H4Me-4)(µ3-R1C2R2)(CO)3(η-C5H5)2](R1= R2= Me or Ph; R1= H, R2= Ph). Reactions of [W2Ru(µ-CC6H4Me-4)(µ3-CC6H4Me-4)(CO)5(η-C5H5)2] with the alkylidyne–tungsten complexes [W(CC6H4Me-4)(CO)2L](L =η-C5H5 or η-C5Me5) afford the tetranuclear metal compounds [W3-Ru(µ-CO)(µ3-η-CO)(µ-CC6H4Me-4)2(µ3-CC6H4Me-4)(CO)2(η-C5H5)2L]. The n.m.r. data for the new compounds are reported and discussed in relation to their structures.