Crystallographic and nuclear magnetic resonance studies of carbonyl(η3-methylallyl)(trichlorostannyl) complexes of platinum(II) and palladium(II)

The complexes [M(η3-C4H7)(SnCl3)(CO)] [C4H7 = 2-methylallyl, M = Pt(1) or Pd(2)] have been prepared and characterized. Their solution behaviour has been studied by n.m.r. spectroscopy, the compounds being dynamic through dissociation of the CO ligand. The X-ray structures of (1) and (2) are reported. Complex (2) is the first mononuclear palladium carbonyl to be characterized by X-ray diffraction. The different stabilities of the two isostructural complexes are correlated with the subtle differences in bonding observed in the crystal structures.