EPR, IR and electronic spectral studies on Ni(II) and Cu(II) complexes with N-donor tetradentate [N4] macrocyclic ligand

Nickel(II) and copper(II) complexes are synthesized with a novel tetradentate macrocyclic ligand, i.e. 2,6,12,16,21,22-hexaaza;3,5,13,15-tetraphenyltricyclo[15,3,1,17–11] docosa;1(21),2,5,7,9,11(22),12,15,17,19-decaene (L) and characterized by the elemental analysis, magnetic susceptibility measurements, mass, 1H NMR, IR, electronic and EPR spectral studies.All the complexes are non-electrolytic in nature. Thus, these may be formulated as [M(L)X2] [M = Ni(II), Cu(II) and X = Cl−, NO3− and (1/2)SO42−]. Ni(II) and Cu(II) complexes show magnetic moments corresponding to two and one unpaired electron, respectively.On the basis of IR, electronic and EPR spectral studies an octahedral geometry has been assigned for Ni(II) and tetragonal geometry for Cu(II) complexes.