Triosmium-antimony clusters containing the μ,η2-phenylene ligand: Unusually long osmium-osmium bonds

The reaction of Os3(μ-H)(μ-SbPh2)(μ3,η2-C6H4)(CO)9 with AsPh3 afforded the adduct Os3(μ-H)(SbPh2)(μ2,η2-C6H4)(CO)9(AsPh3) and the substitution derivative Os3(μ-H)(SbPh2)(μ3,η2-C6H4)(CO)8(AsPh3). Reaction with tBuNC afforded the adduct Os3(μ-H)(SbPh2)(μ2,η2-C6H4)(CO)9(CNtBu) quantitatively. This adduct isomerised slowly on standing via migration of the isonitrile, while photolysis led to decarbonylation to Os3(μ-H)(SbPh2)(μ2,η2-C6H4)(CO)8(CNtBu).