Diazald: An entry to diruthenium complexes containing bridging nitrosyl ligands

Reactions of coordinatively unsaturated complexes [Ru2(μ-PtBu2)(μ-H)(μ-PˆP)(CO)4] (PˆP = bisphosphanes, N,N-substituted bis(diphenylphosphanyl)amines) with the nitrosylating reagent diazald (N-methyl-N-nitroso-p-toluenesulfonamide) were investigated. Thus a convenient synthesis affording a series of new diruthenium complexes containing bridging nitrosyl ligands of the general type [Ru2(μ-PtBu2)(μ-NO)(μ-PˆP)(CO)4] was developed and the crystal and molecular structures of five new compounds were determined. Contrary, this reaction principle does not work for the closely related complex [Fe2(μ-PtBu2)(μ-H)(μ-dppm)(CO)4] (dppm = Ph2PCH2PPh2). In this case carbon monoxide was produced in side reactions and the known compound [Fe2(μ-PtBu2)(μ-H)(μ-dppm)(μ-CO)(CO)4] was obtained as the main product. The molecular structure of the latter complex was also determined by X-ray diffraction.