EPR, IR, Mass and electronic spectroscopic studies on newly synthesized 23,24-dioxo-1,6,9,12,17,20-hexaazacyclotracosa-1,5,12,16-tetraene macrocyclic ligand (L) and its transition metal complexes

Sulekh Chandra and Poonam Pipi

Abstract

Complexes of manganese (II), cobalt(II), nickel(II) and copper(II) complexes have been synthesized with a new tetradentate ligand viz, 23, 24dioxo1,6,9,12,17,20 hexaazacyclotracosa1,5,12,16tetraene (L) and characterized by the elemental analysis, molar conductance measurement, magnetic susceptibility measurements, Mass, IR, electronic and EPR spectral studies. The molar conductance measurements of the complexes in DMF correspond to be non electrolytic nature for Mn(II), Co(II) and Cu(II) while 1:2 electrolytes for Ni(II) complexes. Thus, these complexes may be formulated as [M(L)X2] and [Ni(L)]X2 (Where M=Mn(II), Co(II) and Cu(II) and X=CI- and NO3 -. On the basic of IR, electronic and EPR spectral studies an octahedral geometry has been assigned for Mn(II) and Co(II) complexes, square planar geometry for Ni(II) and tetragonal geometry for Cu(II) complexes. In vitro the ligand and its complexes were against two pathogenic fungi (i.e. alternaria alternata and aspergillus niger) to assess their growth inhibiting potential.