Bonding and structure trends of thiosemicarbazone derivatives of metals—An overview

This review describes the coordination chemistry of thiosemicarbazones and covers all the metals for which complexes are reported. The coordination compounds of d-block, p-block and f-block elements are discussed with respect to their bonding and structures. The description of work is group by group and with a given metal, coordination compounds of all the ligands under purview are described. A brief description of synthesis and spectroscopy of complexes is also given. Several of complexes are mononuclear, with distorted tetrahedral, square planar, square pyramid or octahedral as their common geometries. Dimers, trimers, tetramers, as well as complexes of higher nuclearity are also reported. Variable bonding properties, metallation, metal–metal interactions, role of solvents/other factors in stabilization of sulfur-bridging in coinage metals, and the nature of substituents at azomethine carbon are other interesting features of the review. Further, biological and analytical applications of the ligands/complexes are included in brief so as to indicate the importance of ligands under consideration. The literature survey is complete to December 2007, and some papers of more recent origin are included.