Influence of ligand framework on crystal structures and properties of some dithio complexes

Abstract

Twenty three (23) new homo- and heteroleptic complexes (depicted in Flow scheme), involving dithiocarbamate, xanthate, and#946;-oxodithioester, trithiocarbonate and phosphine ligands have been described in this thesis. The complexes have been fully characterized by elemental analysis, spectroscopic (IR, 1H, 13C{1H} and 31P{1H} NMR, UV-Vis) techniques and their crystal structures have been investigated by single crystal X-ray analysis. Their solid phase conducting behavior has been studied. Luminescent properties of the complexes have been studied in solution and solid phase. The hexanuclear silver(I) (7) and trinuclear Cu(I) (8) clusters show strong fluorescent behavior. Time resolved fluorescence decay curve of these complexes revealed short mean fluorescence lifetime in the order of few nanoseconds. Rare intermolecular C-H···Ni anagostic interactions have been observed in xanthate (2) and dithiocarbamate (4) complexes which have been assessed by theoretical calculations. The phenylmercury(II) and#946;-oxodithioester complexes stabilized the keto form of the ligands. Interestingly the pyridyl functionalized and#946;-oxodithioester complex (23) preferred the less favored S,S-coordination mode over the common O,S-coordination mode. The Hg···O (21 and 22) and Hg···N interactions (23) have been assessed by DFT calculations. The results of these investigations and principal findings of this investigation are described in this thesis in detail [1-5].