Os(dppe)(dppe monoxide)(CO)Cl 2 as an active intermediate in the synthesis of strongly luminescent divalent osmium complexes

Reaction of K 2 OsCl 6 with 1,2-bis(diphenylphosphino)ethane (dppe) in 1:2 ratio afforded the osmium(II) Os(dppe)(dppeO)(CO)Cl 2 complex (where dppeO = 1,2-bis(diphenylphosphino)ethane monoxide) with the molecular structure confirmed by X-ray investigations. The Os(dppe)(dppeO)(CO)Cl 2 intermediate can be simply converted to Os ( dppe ) ( N ∩ N ) ( CO ) Cl + ⋯ PF 6 - 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 Os ( P ∩ P ) ( N ∩ N ) ( CO ) Cl + ⋯ PF 6 - complexes feature strong (with ϕ em up to 0.57) long lived (with τ em up to 25.2 μs) MLCT emission.