Reaction of [(CO)4Mo(μ-Cl)3Mo(SnCl3)(CO)3] with PhCCPh. X-ray crystal structure of [Mo3(μ3-O)(μ3-Cl)(μ2-Cl)(μ2-OH)2(O)(η2-PhCCPh)5]

Reaction of [(CO4Mo(μ-Cl)3Mo(SnCl3)(CO)3] 1 with PhCCPh in inert atmosphere affords the mixture of alkyne halocarbonyl compounds, which after exposure to moist air rearranges to give the complex [Mo3(μ3-O)(μ3-Cl)(μ2-Cl)(μ2-OH)2(O)(η2-PhCCPh5)] 2. The structure of complex 2 was established by X-ray crystallography. The molecule consists of a nearly isosceles triangle of Mo atoms joined by triply bridging oxygen and chlorine atoms. Compound 2 is noteworthy since it is the first trinuclear complex of molybdenum in which a mixed-valence Mo2IIMoIV core has been established.