THERMAL DECOMPOSITION OF VINYL- AND ALLYLSILANE PLATINUM(II) COMPLEXES AND PLATINUM(II) CATALYSED SYNTHESIS OF (E),(E)-1,4-DIPHENYL-1,3-BUTADIENE

Thermal stabilities of Pt(II) complexes: K[PtC(3)(CH(2)=CHSiMe(3))], K[PtCl(3)(CH(2)-CHCH(2)SiMe(3))], K[(acac)PtCl(CH(2)=CHSiMe(3))] and [PtCl(CH(2)=CHCH(2)SiMe(3))](2), were examined. All complexes were found to be stable at room temperature but they decomposed without melting above about 90 degrees C. The allylsilane complex decomposed above about 125 degrees C. All complexes liberated chlorotrimethylsilane on decomposition, showing the facile cleavage of the C-Si bond by nucleophilic attack on the silicon by the chloride ion. (E),(E)-1,4-diphenyl-1,3-butadiene was stercoselectively synthesised in good yield from (E)-beta-styrylsilane in the presence of Zeise's salt.