Di-ruthenium complexes having diphosphines and carbonyls: Formation, structure, and catalytic hydrogenation of alkynes

Reaction of three selected diphos ligands, viz. 1,2-bis(diphenylphosphino)ethane (L1), 1,3-bis(diphenylphosphino)propane (L2) and 1,4-bis(diphenylphosphino)butane (L3), with [{Ru(CO)2Cl2}n] affords di-ruthenium complexes of type [Ru2(L)3(CO)2Cl4], (1-3), which are found to efficiently catalyze hydrogenation of alkynes to the corresponding alkenes.150