Os(dppe)(dppe monoxide)(CO)Cl2 as an active intermediate in the synthesis of strongly luminescent divalent osmium complexes

Reaction of K2OsCl6 with 1,2-bis(diphenylphosphino)ethane (dppe) in 1:2 ratio afforded the osmium(II) Os(dppe)(dppeO)(CO)Cl2 complex (where dppeO = 1,2-bis(diphenylphosphino)ethane monoxide) with the molecular structure confirmed by X-ray investigations. The Os(dppe)(dppeO)(CO)Cl2 intermediate can be simply converted to image species in reaction with N ∩ N chelating diimines like 1,10-phenanthroline, 4,7-diphenyl-1,10-phenanthroline or 3,4,7,8-tetramethyl-1,10-phenanthroline. The obtained mixed image complexes feature strong (with ϕem up to 0.57) long lived (with τem up to 25.2 μs) MLCT emission.