Structural characterisation of heterometallic platinum complexes with non-transition metals. Part I: heterodimeric complexes

Abstract

This review covers 90 heterodimeric Pt complexes with non-transition metals. There are 13 non-transition metals (Ge, Sn, Pb, Ga, In, Tl, Sb, Zn, Cd, Hg, Na, K and Ca). These dimers can be divided into three groups, the first in which only a direct Pt-M bond connects respective units (59%); the second in which in additon to a direct Pt-M bond a ligand/s serves as bridge/s (33%); and the third one in which two respective units are held together via bridge/s ligand/s. The mean Pt-M bond distance elongates in the sequence: 2.425 Å (M=Ge) <2.559 Å (Sb) <2.601 Å (In) <2.625 Å (Cd) <2.657 Å (Hg) <2.663 Å (Sn) <2.670 Å (Pb) <2.674 Å (Tl) <2.760 Å (Zn) <2.960 Å (Ca). The Pt atom has oxidation numbers 0, +2 (most common) and +4, and the M atoms have +1, +2 (most common), +3 and +4. The Pt coordination geometrics include square planar (most common), trigonal bi­pyramidal, pseudo-octahedral Pt(IV). There are examples which contain two independent dimers (distortion isomers). Factors affecting bond distances and angles are discussed and some ambiguities in coordination poly­hedra are outlined.

Keywords

• non-transition metal
• platinum heterodimers
• structure
• trans effect