Reactions of the complexes Pt 3(μ-CO) 3L 3 with SO 2. Crystal structure of Pt 3(μ-CO) 3(P tBu 2Ph) 3·0.25(C 4H 8O)

Abstract

Reactions of the complexes Pt 3(μ-CO) 3L 3, where LP tBu 3 ( 1a), P tBu 2 cPr ( 1b), P tBu 2Ph ( 1c), PCy 3 ( 1d) and PCy 2Ph ( 1e), with SO 2 have been examined. The complexes 1 may be divided into two classes: those complexes ( 1a, 1b and 1c) which fragment to yield a dimer Pt 2(μ-SO 2)(CO) 2L 2, where L=P tBu 3 ( 2a), P tBu 2 CPr ( 2b), P tBu 2Ph ( 2c), upon brief exposure to SO 2 and those complexes ( 1d and 1e) which substitute CO ligands with SO 2 ligands without a change in nuclearity to yield Pt 3(μ-SO 2) 3L 3, where L=PCy 3 ( 3d) and PCy 2Ph ( 3e). Traces of the complexes Pt 3(μ-SO 2)(μ-CO) 2L 3 (4) were observed after heating the complexes 2 under an SO 2 atmosphere for 14 h. As formation of dimeric products appeared to be favoured by larger ligands L, a method of evaluating the non-bonding interactions between the ligands L and the cluster fragment Pt 3(μ-CO) 3 was used to evaluate the size to the phosphine ligands. The X-ray crystal structure of the complex Pt 3(μ-CO) 3(P tBu 2Ph) 3 ( 1c) is reported.