Stereochemistry of Pt(η2-P2L)Cl2 derivatives

The coordination chemistry of platinum (Pt) covers a huge field as shown by a recent survey covering the crystallographic and structural data of almost 200 monomeric examples of the Pt(η2-P2L)Cl2type. About 20% of these complexes exist as isomers and are discussed in this review. Included are distortion (64%),cis-trans(20%), and ligand (16%) isomers. These are discussed in terms of the metallocyclic rings, and coordinations are drawn between donor atoms, bond lengths, and interbond angles, with attention to anytrans-influence. Distortion isomers, differing only by the degree of distortion in Pt-L and L-Pt-L angles, are the most numerous. In this series of distortion and ligand isomers, the square-planar configuration about the Pt(II) atom has onlycis-configuration. The total mean values of Pt-L bond distances (cis- vs.trans-configuration) are 2.228 Å (P) and 2.353 Å (Cl) vs. 2.312 (P) and 2.302 Å (Cl).