Transition metal-mediated donor–acceptor coordination of low-oxidation state Group 14 element halides

Abstract

The reactivity of tungsten carbonyl adducts of Group 14 element (Ge, Sn and Pb) dihalides towards the metal-based donors (η⁵-C₅H₅)Rh(PMe₂Ph)₂ and Pt(PCy₃)₂ was examined. When (η⁵-C₅H₅)Rh(PMe₂Ph)₂ was treated with the Lewis acid supported Ge(II) complex, THF·GeCl₂·W(CO)₅, cyclopentadienyl ring activation occurred, whereas the analogous Lewis acidic units SnCl₂·W(CO)₅ and PbCl₂ form direct adducts with the Rh complex to yield Rh–Sn and Rh–Pb dative bonds. Attempts to prepare metal coordinated element(II) hydrides by adding hydride sources to the above mentioned rhodium–E(II) halide complexes were unsuccessful; in each case insoluble products were formed along with regeneration of free (η⁵-C₅H₅)Rh(PMe₂Ph)₂. In a parallel study, ECl₂·W(CO)₅ (E = Ge or Sn) groups were shown to participate in E–Cl oxidation addition chemistry with (Cy₃P)₂Pt to give the formal Pt(II) complexes ClPt(PCy₃)₂ECl·W(CO)₅.