Abstract

A new class of Zr-M heterobimetallic complexes (M = Fe, Ru, Co) containing the CH2(CH2-NSiMe3)2(Cp)Zr fragment as a building block has been synthesized by salt metathesis of CH2(CH2NSiMe3)2(Cp)ZrCl (5) with KCpM�(CO)2 (M� = Fe, Ru) and NaCo(CO)3(PR3) (R = Ph, Tol). The zirconium half-sandwich complex 5 was obtained in four reaction steps from ZrCl4 via the spirocyclic complex CH2(CH2NSiMe3)22Zr (1), the (diamido)dichlorozirconium complex CH2(CH2NSiMe3)2ZrCl2 (2), and its soluble THF-adduct CH2(CH2NSiMe3)2-ZrCl 2(THF)2 (3). The latter was converted to 5 in good yield by reaction with LiCp. The Zr-Fe heterodinuclear complex CH2(CH2NSiMe3)2(Cp)Zr-Fe(CO) 2Cp (6) has been characterized by X-ray crystal structure analysis which has established the presence of an unsupported Zr-Fe bond. The v(CO) infrared bands of the CpM�(CO)2 moieties in the Zr-M� complexes (M� = Fe, Ru) indicate a significant ionic contribution to the Zr-M� bonding. © 1995 American Chemical Society.