Abstract
The heterometallic tetranuclear ketenyl compound [Os 3 (CO) 10 (μ-H){C(O)CH 2 W(CO) 3 (η-C 5 Me 5 )}] 1 possessing a pendant W(η-C 5 Me 5 )(CO) 3 substituent is prepared by condensation of [Os 3 (CO) 10 (NCMe) 2 ] with the aldehyde complex [W(η-C 5 Me 5 )(CO) 3 (CH 2 CHO)]. Pyrolysis of 1 in the solid state at 185 °C afforded four tetrahedral compounds [WOs 3 (η-C 5 Me 5 )(CO) 9 (μ-O)(μ 3 -CMe)] 2, [WOs 3 (η-C 5 Me 5 )(CO) 9 (μ-O)(μ-H)(μ-CHMe)] 5, [WOs 3 (η-C 5 Me 5 )(CO) 11 (μ 3 -CMe)] 3 and [WOs 3 (η-C 5 Me 5 )(CO) 11 (μ 3 -CH)] 4, demonstrating a unique example of C-O bond scission for the ligated ketene fragment. Since treatment of 2 with H 2 in toluene also afforded 5 in moderate yield, it is highly probable that the latter is produced via reaction with trace amounts of H 2 generated from the decomposition of 1. The molecular structures of 2 and 4 have been determined by single-crystal X-Ray analysis.