Using Zirconium Half-Sandwich Complexes as Building Blocks in a New Class of Zr-M Heterobimetallics Containing Unsupported Zr-M Bonds (M = Fe, Ru, Co)
作者:Stefan Friedrich、Lutz H. Gade、Ian J. Scowen、Mary McPartlin
DOI:10.1021/om00011a060
日期:1995.11
A new class of Zr-M heterobimetallic complexes (M = Fe, Ru, Co) containing the CH2(CH(2)NSiMe(3))(2)(Cp)Zr} fragment as a building block has been synthesized by salt metathesis of CH2(CH(2)NSiMe(3))(2)(Cp)ZrCl (5) with K[CpM'(CO)(2)] (M' = Fe, Ru) and Na[Co(CO)(3)(PR(3))] (R = Ph, Tol). The zirconium half-sandwich complex 5 was obtained in four reaction steps from ZrCl4 via the spirocyclic complex [CH2(CH(2)NSiMe(3))(2)]Zr-2 (1), the (diamido)dichlorozirconium complex CH2(CH(2)NSiMe(3))(2)ZrCl2 (2), and its soluble THF-adduct CH2(CH(2)NSiMe(3))(2)ZrCl2(THF)(2) (3). The latter was converted to 5 in good yield by reaction with LiCp. The Zr-Fe heterodinuclear complex CH2(CH(2)NSiMe(3))(2)(Cp)Zr-Fe(CO)(2)Cp (6) has been characterized by X-ray crystal structure analysis which has established the presence of an unsupported Zr-Fe bond. The nu(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.