Heterotridentate organodiphosphines in Pt(η3–P1X1P2)(Y) derivatives-structural aspects

This review covers over 30 examples of monomeric Pt(II) complexes of the types: Pt(η3–P1O1P2)(Y) (Y = PL, CL, OL), Pt(η3–P1N1P2)(Y) (Y = H, NL, CL, Cl, PL) and Pt(η3–P1P2N1)(Y) (Y = Cl). The heterotridentate donor ligands create 11 types of a couple chelate rings with common central atom O1 (η3–P1O1P2), N1 (η3–P1N1P2) and P2 (η3–P1P2N1). The most frequent is P1C2N1C2P2. Some cooperative effects between chelate rings and Y donor ligands were found and discussed. A degree of distortions of square-planar geometry about Pt(II) were also calculated.

Organodiphosphines in Pt{η2-P(X)nP}Cl2 (n = 9–15, 17, 18) derivatives – Structural aspects

This review covers over 20 monomeric platinum complexes of Pt{η2-P(X)nP}Cl2 (n = 9–15, 17, 19) type. The chelating P,P-donor ligands create wide varieties of the metallocyclic rings: 12-membered (PC9P, PC3NCNC3P), 13-membered (PC3NC2NC3P), 14-membered (PC11P, PO(SiO)5P, PC2OC2OC2OC2P), 15-membered (PC12P), 16-membered (PCOC9OCP), 17-membered (P(C2O)4C2P), 18-membered (PC2OC9OC2P, PC4NC2NC2NC4P), 20-membered (P(C2O)5C2P), and 21-membered (POC2NC10NC2OP). For these complexes the most common is a predominantly cis-arranged with 17 examples and only four examples with trans-configuration. The total mean values of Pt–L bond distances in the complexes with cis- versus trans-configuration are: 2.252 Å (P trans to Cl), 2.355 Å (Cl trans to P) vs 2.288 Å (P trans to P), and 2.304 Å (Cl trans to Cl). There are examples which exist in cis- and trans-isomeric forms and distortion isomers. A brief survey on the structural data of almost 180 examples of Pt{η2-P(X)nP}Cl2 (n = 1–8) type complexes is added and discussed.

Stereoisomers of Pt(PL)2Cl2 derivatives – structural aspects

The coordination complexes of Pt(PL)2Cl2type (PL = monodentate P-donor ligands) cover almost 260 examples as shown by a recent survey covering the crystallographic and structural data. About 20% of these complexes exist as isomers and are summarized in this review. Included are distortion (58.5%),cis-,trans- (37.8%) and mixed isomerism (cis-,trans- and distortion) (3.7%). Distortion isomers, differing by degree of distortion in Pt-L and L-Pt-L angles, are the most common. For these derivatives the most commoncis- arranged with 31 examples and 22 examples withtrans- arranged. The complexes withcis-configuration are more distorted than theirtrans-partners, with the comprehensive values of Pt-L bond distances: 2.246 Å (P) and 2.350 Å (Cl). Such values in the complexes withtrans-configurations are 2.323 Å (P) and 2.308 Å (Cl), respectively. These are discussed with attention to anytrans-influence.

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).