Synthesis and X-ray crystallographic studies of Ni (II) and Cu (II) complexes of [5-(4-pyridyl)-1,3,4] oxadiazole-2-thione/thiol formed by transformation of N-(pyridine-4-carbonyl)-hydrazine carbodithioate in the presence of ethylenediamine

Abstract

The reaction of [M(H 2L) 2] [M = Ni(II) Cu(II)] (K +H 2L − = N-(pyridine-4-carbonyl)-hydrazine carbodithioate) with excess of ethylenediamine (en) gave mixed ligand complexes [Ni(en) 2(4-pytone) 2] (4-pytone = 5-(4-pyridyl)-1,3,4-oxadiazole-2-thione), and [Cu(en) 2](4-pytol) 2·H 2O (4-pytol = 5-(4-pyridyl)-1,3,4-oxadiazole-2-thiol). The metal complexes have been characterized with the aid of elemental analyses, IR, magnetic susceptibility and single crystal X-ray studies. Complexes ( 1) and ( 2) crystallize in monoclinic system, space group P 1 21/ n 1 and C 2/ c, respectively. The ligand after cyclization is present in the deprotonated thiol form in the Cu(II) complex where it is ionically bonded through sulfur. In the Ni(II) complex ( 1) bonding of the ligand take place through oxadiazole nitrogen and the ligand exists as the thione form.