Chelating ligands cadmium

The difference in behaviour has been attributed to the preferred formation, by cadmium(II) and mercury(II), of [MX2]oo chains in which pairs of chloride anions link metal centres to give a square planar MX/ arrangement, the octahedral coordination sphere then being completed by two monodentate bu molecules [MX2]oo chain formation does not occur for copper(II) and zinc(II) and so the anions only occupy two of the six available co-ordination sites allowing bu to act as a bidentate chelating ligand. 

Tripod ligands of the pyrazolyl/thioimidazolyl-borate offering N2S, NS2, and S3-donor sets were employed in the study of biologically relevant alkylations of the R-thiolate zinc complexes (R = ethyl-, benzyl-, phenyl-, and p-nitrophenyl).78 A review recently described the use of poly(mercaptoimidazolyl)-borate in the chelation of cadmium and mercury.107... 

Chelates are often named merely as a complex, eg, cadmium complex with acetylacetone. A common practice ia the Hterature is to give the symbol of the central atom and an abbreviation for the ligand with or without an iadication of ionic charges, oxidation states, stmcture, or counterions, as ia the foUowiag Pb-EDTA, Cacit , Cu(en)2, Co(II)-(phen), [Cu(dipy)2]S04, [Ru(dipy)2(en)], and Na[Co(acac)2]. Ligand abbreviations are given ia Table 1. 

An example of a high coordination number for cadmium is found in aquabis(4-aminobenzoato)cadmium(II),793b which involves seven-coordinate cadmium, with two chelating carboxylate groups, a water molecule and axial positions filled by amino groups from ligands bound to the neighbouring metal centres.794... 

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