IMIDAZOLINE-2-YLIDENE METAL-COMPLEXES WITH PENDANT FERROCENYL SUBSTITUENTS

Imidazolium and benzimidazolium salts with ferrocenylated alkyl side c hains are prepared as progenitors of N-[(ferrocenyl)alkyl](benz)imidaz oline-2-ylidene carbenes, which form metal complexes of W(0), Pd(II), and Hg(II). X-ray structures and other spectroscopic properties show t hat these carbene precursors and complexes are analogous to published non-ferrocenylated complexes with regard to the coordination sphere at the metal, but different in terms of steric protection of the central metal by the bulky ferrocenyl substituents and in terms of distinguis hable redox potentials of the ferrocene/ferrocenium couple. (C) 1998 E lsevier Science S.A.