Structure and fluxional behavior of platinum and palladium complexes having M-Si or M-Sn (M = Pt or Pd) inter-element linkages

Hexamethyldistannane reacts with Pt{P(MeC6H4)(3)}(4) at -30 degrees C to af ford the oxidative addition product: cis-[Pt(SnMe3)(2){P(MeC6H4)(3)}(2)]. T he structure is distinctly distorted from planarity: the dihedral angle bet ween the P-Pt-P and the Sn-Pt-Sn planes is 34.6 degrees. The solution P-31- NMR spectra indicate that the complex shows reversible fluxional behavior. The fluxional process is attributed to the intramolecular twist-rotational motion via pseudo tetrahedral transition state. A similar fluxional process is observed with bis(silyl)bis(phosphine)platinum and bis(stannyl)bis(phos phine)palladium complexes. (C) 2000 Elsevier Science S.A. All rights reserv ed.