Synthesis and spectral studies of Cu(II), Ni(II), Co(II), Mn(II), Zn(II) and Cd(II) complexes of a new macroacyclic ligand N,N′-bis(2- benzothiazolyl)-2,6-pyridinedicarboxamide

Abstract

A new macroacyclic amide ligand N,N′-bis(2-benzothiazolyl)-2,6- pyridinedicarboxamide (BPD), formed by the condensation of 2,6- pyridinedicarbonyldichloride with 2-aminobenzothiazole, and its Cu(II), Ni(II), Co(II), Mn(II), Zn(II) and Cd(II) complexes were synthesized. Their structures were elucidated on the basis of elemental analyses, conductance measurements, magnetic moments, spectral (IR, NMR, UV-Visible, EPR and FAB) and thermal studies. The complexes exhibit an octahedral geometry around the metal center. Conductance data of the complexes suggested them to be 1:1 electrolytes. The pentadentate behavior of the ligand was proposed on the basis of spectral studies. The X-band EPR spectra of the Cu(II) and Mn(II) complexes in the polycrystalline state at room (300 K) and liquid nitrogen temperature (77 K) were recorded and their salient features are reported.