Studies on the transition metal ion complexes of pyrazole containing ligands having n and s donor atoms

Abstract

One of the most well-known and fascinating characters of coordination chemistry is the newlinefrequent use of organic compounds with suitably spaced donor atoms as ligands towards newlinemetal ions for the synthesis of novel metallo-organic compounds; the metal ion complexes newlinefrequently carry on diverse potentialities in a variety of fields especially in biological newlinesciences. Although classical examples of heterocyclic compounds acting as ligands for the newlineformation of complexes with metal ions have been pyridine, picoline, quinoline, isoquinoline newlineetc. (contain one hetero-atom i.e. nitrogen as the donor site), yet important attention has been newlineextended for the last few years to the heterocycles containing more than one hetero-atom, newlinenamely, imidazole (1:3 diazole), pyrazole (1:2 diazole), pyrazine (1:4 diazine), pyrimidine newline(1:3 diazine) etc. with potential donor sites to form various transition metal ion complexes; newlineduring complexation, the and#61552;-electrons on the hetero-atom actively take part in the formation of newlinestable metal-ligand (M-L) bonds. On the other hand, thiosemicarbazones and their metal ion newlinecomplexes have achieved significant attention due to their various beneficial pharmacological newlineactivities. Metal ion complexes of thiosemicarbazones exhibit numerous applications, e.g. newlineantibacterial, anticancer, antitumour, antiviral and other biological activities, which have newlineoften been correlated to their chelation abilities with transition metal ions with an immense newlineanticipation that the complexes might have shown useful beneficial therapeutic properties, as newlinereflected in several review articles. newline