Molecular Structure of π-alyll-palladium Acetate

Abstract

THE structures of π-allyl complexes of transition metal ions are of interest because the allyl ligand can be regarded as intermediate in behaviour between olefines and conjugated aromatic systems. π-Allyl palladium complexes have, in particular, assumed importance as catalytic agents in carbonylation and other reactions involving unsaturated organic halides1,2. The only structural analysis of an allyl complex so far reported is that of the dimeric π-allyl palladium chloride3, the reaction of this complex with silver acetate yielding π-allyl palladium acetate4. A three-dimensional X-ray analysis of the structure of this molecule has now been completed, the molecular stereochemistry being shown in Fig. 1; estimated standard deviations of the observed bond lengths are 0.003 A (Pd–Pd), 0.02 A (Pd–O), 0.035 A (Pd–C), 0.04 A (O–C) and 0.05 A (C–C) and correspond to a discrepancy index of 0.068 for 1,065 reflexions.