Preparation, characterization and redox chemistry of oxo-centered triruthenium dimers linked by bis(diphenylphosphino)anthracene and -ferrocene

Diphosphine-bridged dimers of oxo-centered triruthenium–acetate cluster units, i.e., [{Ru3O(OAc)6(py)2}2(dppan)](PF6)2 (2) and [{Ru3O(OAc)6(py)2}2(dppf)](PF6)2 (3) were prepared by reaction of 2.3 equivalent [Ru3O(OAc)6(py)2(CH3OH)](PF6) with 9,10-bis(diphenylphosphino)anthracene (dppan) or 1,1′-bis(diphenylphosphino)ferrocene (dppf), respectively. Apparent redox wave splitting is observed in complex 2, revealing the presence of electronic communication between two triruthenium units mediated through bridging dppan. The complexes were characterized by elemental analysis, IR, UV–Vis, 31P NMR, and ES-MS spectroscopies, and cyclic and differential-pulse voltammetry. The crystal structure of complex 3 was determined by X-ray crystallography.