Novel diphosphine platinum cations: NMR and Moessbauer spectra and catalytic studies

Article abstract of DOI:10.1016/0022-328X(95)05630-8

The reaction of PtCl₂(diphosphine) with mono and bidentate phosphines has been investigated by NMR spectroscopy. [Pt(diphosphine)(PMe₃)₂]²⁺, [Pt(diphosphine)₂]²⁺ and [Pt((S,S)-bdpp)((S,S)-chiraphos)]²⁺ cations have been characterized by ³¹P NMR and conductivity measurements. The presence of tin(II) chloride promotes the formation of the complex cations. Evidence for coordination of the diphosphine in monodentate mode has been obtained by NMR spectroscopy. The platinum species possessing a platinum-tin bond and ionic complexes with an SnCl^-₃ counterion can easily be distinguished by ¹¹⁹Sn Moessbauer spectroscopy. Asymmetric hydroformylation of styrene with [Pt((S,S)-bdpp)₂]²⁺ (SnCl^-₃)₂ as catalyst precursor gave chemo-, regio-and enantio-selectivities different from those obtained with the covalent PtCl(SnCl₃)((S,S)-bdpp) as catalyst precursor.