Stereochemistry of Platinum Organometallics

The organometallic chemistry of platinum covers a huge field, as shown by a recent survey covering the crystallographic and structural data of almost one thousand organometallic derivatives. About nine percent of those derivatives exist as isomers and are summarized in this review and include distortion (90 %), cis trans (6%) and ligand isomerism (4%). These are discussed in terms of the coordination about the platinum atom, and correlations are drawn between donor atom, bond length and interbond angles, with attention to any trans effect. Distortion isomers, differing only by degree of distortion in Pt-L bond lengths and LPt -L bond angles, are the most numerous. They are also spread over a wider range of oxidation states of platinum, (zero, +1, +2, +4, mixed valence +1 plus +2 and +2 plus +4), compared to cis-trans and ligand isomerism in which only +2 is found.