Substituted metal carbonyls. XXII . Synthesis of 1,1′-bis(diphenylphosphino)ferrocene-bridged complexes with two heterometallic AuM (M Mn and Re) bonds

Abstract

AU2Cl2(μ-1,1′-bis(diphenylphosphino)ferrocene (dppf) reacts with Na[M(CO)5] to give [AuM(CO)5]2(μ-dppf) (M Re (1); M Mn (2)) in 45% and 71% yields respectively. Both 1 and 2 represent pentametallic structures with a dppf metalloligand bridging between two heterometallic fragments which consist of AuM bonds. The X-ray photoelectron spectroscopic data suggested polarization of the Auδ+Reδ- bonds in 1. Contrary to 1, (CO)9Re2(μ-dppf)AuCl (3), which is synthesized from Re2(CO)9(dppf-P) and AuCl(Me2S) in 65% yield, shows binding energies typical of AuI and Re0. Reaction between Au2Cl2(μ-dppf) and K2Pd(CN)4 resulted in no MM bond but ligand displacement to give Au2(CN)2(μ-dppf) (4) (yield, 8%) as the only isolable product. © 1993.