Pentamethylcyclopentadienyl Halfsandwich Complexes of Rhodium and Iridium Containing 1,1′-Ferrocene Dichalcogenido Ligands

Abstract

A series of 12 bimetallic complexes Cp M(L)[(EC 5 H 4 ) 2 Fe] (M(L) = Rh(PMe 3 ), Ir(PMe 3 ), Ir(PPh 3 ) and Ir(CNtBu); E = S, Se, Te) has been synthesized from the dichlorides Cp M(L)Cl 2 . The new compounds have been characterized by their 1H, 13 C and 31 P NMR spectra in solution. The mass spectra indicate that the two-electron ligand L is preferentially eliminated upon electron-impact. Oxidation by AgBF 4 to give ferrocenium-type cations also occurs readily. An X-ray structure analysis of CpRh(PMe 3 )[(SC 5 H 4 ) 2 Fe] (la) confirms the presence of a 1,1′-ferrocene dithiolate ligand with parallel and ecliptic cyclopentadienyl rings. The long Rh ... Fe (430.4(1) pm) distance rules out any direct interaction between the rhodium center and the iron in the cavity of the ferrocene sandwich.