SYNTHESIS, SPECTRAL INVESTIGATION AND BIOLOGICAL EVALUATION OF NOVEL MACROCYCLIC LIGAND AND ITS TRANSITION METAL COMPLEXES

Satya Shukla, *Sulekh Chandra, Amit Kumar

ABSTRACT

A novel series of macrocyclic complexes of Mn(II), Co(II), Ni(II) and Cu(II) were synthesized by using condensation reaction between macrocyclic ligand and corresponding transition metal salts. The chemical composition of ligand was determined on the basis of analytical and spectral techniques i.e. elemental analyses, IR, mass and computational study i.e. molecular modelling studies. Data obtained by spectral studies revealed tetradentate nature [N4] of ligand and ligand coordinated to metal ion through nitrogen donor atoms. Metal complexes were characterized by elemental analyses, molar conductance, magnetic susceptibility measurements, IR, electronic spectra, EPR spectra and molecular modelling study. The molar conductance data suggested nonelectrolytic nature of metal complexes and formulated as [M(L)X2] where M = Mn(II), Co(II), Ni(II), Cu(II) L = macrocyclic ligand X = Cl-, NO3 - anion. On the basis of characterization data, all metal complexes possessed octahedral geometry around the metal ion except Cu(II) complex which possessed tetragonal geometry. Geometry of ligand and its complexes was also optimized by using molecular modelling study and it supports to the spectral data results. Newly synthesized macrocyclic ligand and its metal complexes were screened to evaluate the biological activity against some selective microorganisms (bacteria and fungi). The biological experimental result suggested that metal complexes were more potent than ligand.

Keywords: macrocyclic ligand, metal complexes, spectral data, molecular modelling, bacteria, fungi.