Synthesis and spectroscopic characterization of transition metal complexes of a 12-membered tetraaza [N4] macrocyclic ligand and their biological activity
ABSTRACT Cobalt(II), nickel(II) and copper(II) complexes are synthesized with 1,3,7,9-tetraaza- 4,6,10,12-tetraphenyl-2,8-dithiacyclododecane,
a tetradentate ligand (L) and characterized by elemental analysis, molar conductance measurements, magnetic susceptibitity
measurements, mass, i.r., electronic and e.p.r. spectral studies. All the complexes are non-electrolytes so they may be formulated
as [M(L)X2] [where, M = Co(II), Ni(II) and Cu(II) and X = Cl− and NO
]. All the complexes are of high spin type. On the basis of i.r., electronic and e.p.r. spectral studies an octahedral geometry
has been assigned for Co(II) and Ni(II) complexes and tetragonal geometry for Cu(II) complexes. The antimicrobial activities
of the ligand and its complexes, as growth inhibiting agents, have been screened in vitro against two different species of bacteria and plant pathogenic fungi.