SUBSTITUTED METAL-CARBONYLS .22. SYNTHESIS OF 1,1'-BIS(DIPHENYLPHOSPHINO)FERROCENE-BRIDGED COMPLEXES WITH 2 HETEROMETALLIC AU-M(M = MN AND RE) BONDS

Au2Cl2(mu-1,1'-bis(diphenylphosphino)ferrocene (dppf) reacts with Na[M (CO)5] to give [AuM(CO)5]2(mu-dppf) (M = Re (1); M = Mn (2)) in 45% an d 71% yields respectively. Both 1 and 2 represent pentametallic struct ures with a dppf metalloligand bridging between two heterometallic fra gments which consist of Au-M bonds. The X-ray photoelectron spectrosco pic data suggested polarization of the Au(delta+)-Re(delta-) bonds in 1. Contrary to 1, (CO)9Re2(mu-dppf)AuC] (3), which is synthesized from Re2(CO)9(dppf-P) and AuCl(Me2S) in 65% yield, shows binding energies typical of Au(I) and Re0, Reaction between Au2Cl2(mu-dppf) and K2Pd(CN )4 resulted in no M-M bond but ligand displacement to give Au2(CN)2(mu -dppf) (4) (yield, 8%) as the only isolable product.