Metal-metal interaction through CH2-CN bridge: Synthesis and characterization of [CpM(L2) NCCH2Fc]PF6 complexes (Fc = ferrocenyl; L = 1/2 dppe, PPh3; M = Fe,Ru)

Abstract

The new complexes [CpM(L2)NCCH2Fc]PF6 (M = Fe 1, Ru 2; Fc = ferrocenyl), have been prepared from reaction of CpM(L2)X and the ligand Fc-CH2CN 3 in methanol and in the presence of NH4PF6. The compounds were characterized by elemental analysis as well as spectroscopic methods. Electrochemical as well as near-IR measurements suggest a weak metal-metal interaction for the Fe(II)-Fe(III) complex. Hush parameters for this mixed-valence complex suggest a class II Robin-Day type with a moderate metal-metal interaction similar to that observed in the related pyridine bridged systems (η5-C5H5)Fe-η5-C5H4-C5H4N-ML(n). The unusual electron transfer through a insulating CH2 group is the first such example for an asymmetric binuclear system. (C) 2000 Elsevier Science S.A.