Dinuclear and trinuclear osmium complexes incorporating 1,2-bis(2-pyridyl)ethene as doubly and triply bridging ligands: crystal structures of [Os2(μ:η4-C12H10N2)(CO)6], [Os3(μ-H)2(μ3:η3-C12H10N2)(CO)8] and [Os3(μ-H)(μ3:η4-C12H9N2)(CO)8]

The reaction of (C12H10N2) with [Os3(CO)10(CH3CN)2] generated the products 1 to 5. The thermal conversion observed for [Os3(μ-CO)(μ3:η3-C12H10N2)(CO)8] 5 to [Os3(μ-H)(μ3:η4-C12H9N2)(CO)84 by rupture of an Os-C bond with H migration from the CH2 group to the metallic triangle to form a hydride and CO elimination can be seen as a facile process for the formation of the μ:η2-alkenyl complex 4.