Isomers in the Chemistry of Lead Compounds

Abstract

Chemistry of lead compounds covers a wide field, as shown by a recent survey covering the crystallographic and structural data of almost one thousand derivatievs. About 7 % of these derivatives exist as isomers and are summarised in this review. Included are distortion (60 %), ligand (20 %), coordination (12 %) and polymerisation (8 %) isomerism. These are discussed in terms of coordination about the lead atom, and correlations are drawn between donor atom, bond lengths and interbond angles.Distortion isomers, differing only by degree of distortion in Pb -L and L-Pb-L angles, are the most common. Distortion and ligand isomerism spread over a wider range of oxidation state of lead + 2 (most common), + 3 and + 4, than coordination number and polymerisation isomerism ( + 2 only). CONTENTS ABBREVIATIONS

Isomers in the Chemistry of Germanium Heterometallic Clusters

“…This review and its precursors [2,3,[19][20][21][22][23] give the first overall survey of the structural data for isomer complexes of the group IV metals.…”

“…In the chemistry of the group IV metal complexes exists four hundred as isomers, with the seventy four examples in the chemistry of germanium [2, 3 and present review], two hundred and fifty six of tin [19][20][21][22] and seventy of lead complexes [23]. The isomers exists in the following crystal classes: monoclinic (x 38) > triclinic (x 27) > orthorhombic ( Structural data of all four hundred isomers showed that stereoisomers dominate in the chemistry of the group IV metals.…”

Isomers in the Chemistry of Germanium Coordination Compounds

“…In Ge(II) complexes are trigonal planar with varied degrees of distortion: GeCl 3 ,GeI 3 , GeI 2 P and GeSi 2 Ge; and tetrahedral GeN 4 This review, together with its precursors [23,24] represents the first overall survey of the structural data of isomers for the non-transition sub-group (Ge -Sn -Pb). Interesting while in lead complex chemistry exists several types of isomers included distortion (60 %) ligand (20 %), coordination (12 %) and polymerization (8 %) [24], in tin coordination chemistry distortion (96.5 %) and cis -trans (3.5 %) [23], in the germanium coordination chemistry distortion isomerism with one example which contains in the same crystal distortion and coordination isomers, and it is rarity. Generally, the distortion isomerism in this sub-group by far prevails.…”