Intermediates in the Palladium-Catalysed Reactions of 1,3-Dienes, Part 5 [1] Butadiene Complexes of Nickel, Palladium and Platinum

Abstract

A series of [M(R 2 PC 2 H 4 PR 2 )(butadiene)] complexes of Ni, Pd and Pt has been prepared and their structures investigated NMR-spectroscopically. The nickel and palladium complexes, irre­spective of the substituents at phosphorus, contain a fluxional η 2 -bonded butadiene molecule. In the case of platinum the bonding mode is ligand dependent: an η 2 -arrangement is observed where R is tert-butyl or cyclohexyl while when R is isopropyl the butadiene adopts an η 1 , η 1 -arrangement to give a platinacyclopentene derivative.