The synthesis of substituted bis[(diarylphosphinomethyl)cyclopentadienyl]zirconocene dichloride complexes for the preparation of heterodimetallic complexes containing early/late transition metal combinations

Fulvenes (la-e) derived from condensation of cyclopentadiene with acetone or a variety of aldehydes were treated with LiPAr2 (Ar = phenyl, p-tolyl) to yield the respective substituted (diarylphosphinomethyl)cyclopentadienides (2, 3). Subsequent reaction with ZrCl4(THF)(2) gave the respective bis [(diarylphosphinctmethyl)cyclopentadienyl] dichlorides (Ar = phenyl (4), p-tolyl (5)). The complex rac-[C5H4-CH(CH3)-PPh2](2)ZrCl2 (rac-4b) was characterized by X-ray diffraction. The reaction of complexes 4a and 5a [(Cp-CMe2-PAr2)(2)ZrCl2] with PdCl2(NCPh)(2) or PtCl2(NCPh)(2) leads to the formation of the trans-(metallocene-chelate-phosphane)metal complexes 6-9 (e.g. trans-Cl2Pd(Ph2P-CMe2-Cp)(2)ZrCl2]. Chloride abstraction from the reaction product of [CpCH(CMe3)PPh2](2)ZrCl2 with PdCl2(NCPh)(2) eventually gave the cationic complex [meso,trans-(Cp-CH(CMe3)PPh2)(2)(Cl)Zr(mu-Cl)Pd(Cl)](+) (10) that was also characterized by X-ray diffraction. It features a dimetallabicyclic framework with two Cp-CHR-PPh2 ligands and a chloride bridging between the early and the late transition metal center. (C) 1998 Elsevier Science S.A.