Transition metal—carbon bonds: XXXVIII. Alkenyl—platinum(II) complexes from platinum acetylides

Abstract

Platinum(II) acetylides of the type trans-[Pt(CCR) 2(PMe 2Ph) 2] (R = CH 2OMe, CMe 2OH, Ph) are reduced by hydrazine hydrate to dialkenylplatinum(II) complexes of the type trans-[Pt(CHCHR) 2(PMe 2Ph) 2] in which the hydrogens are mutually cis on the alkenyl double bonds. Some of the complexes exist as rotational isomers in solution due to restricted rotation about the PtC single bonds. Mono-alkenyl complexes [PtCl(CHCHR)(PMe 2Ph) 2] (R = Ph or CMe 2OH) were prepared by the hydrogen chloride fission of the dialkenyl complexes. trans-[PtCl(CClCHCH 2OMe)(PMe 2Ph) 2] is formed when trans- [Pt(CCCH 2OMe) 2(PMe 2Ph) 2] is treated with hydrogen chloride whereas similar treatment of [Pt(CCCMe 2OH)(PMe 2Ph) 2] gives [PtCl(CClCHCMeCH 2)(PMe 2Ph) 2]. 1H, 13C and 31P NMR data are given and discussed.