Organodiphosphines in Pt(II) coordination complexes

Abstract

Organodiphosphines are very useful as soft P,P donor ligands in the chemistry of platinum. In this review are summarized and analyzed almost 200 Pt(II) complexes that contain at least one organodiphosphine ligand. There are Pt(II) atoms in a square planar environment with a wide variability of inner coordination spheres: PtP 4 , PtP 3 X (X = H, Cl, S, Br), PtX 2 P 2 (X = O, N, C, B, Cl (most common), S, Br, Se, Si, I, Te), PtP 2 XY (XY = H+O, H+Cl, H+Si, O+N, O+Si, N+S, N+Se, Cl+Si). The cis derivatives, by far, prevail. There are four basic Pt P (organodiphosphine) bond distances and their mean values elongated in the order: 2.270 Å (chelated) < 2.290 Å (bridged) < 2.322 Å (trans to C) < 2.348 Å (trans to H). Organodiphosphines form a wide variability of metallocycles from 4-to even 20-membered, with 4-and 5-membered being the most common ring size. Some examples exist as isomers, differing mostly by the degree of distortion and are examples of distortion isomerism. In the series of monomeric Pt(II) complexes, the mean Pt P (bidentate) bond distance elongated in the order: 2.235 Å (PtP 2 X 2 ) < 2.270 Å (PtP 2 XY) < 2.290 Å (PtP 3 X) < 2.320 Å (PtP 4 ).