Modern spectroscopic and biological approach in the characterization of a novel 14-membered[N4]macrocyclic ligand and its transition metal complexes

摘要

A novel tetradentate nitrogen donor[N4]macrocyclic ligand,i.e.1,3,4,8,9,11-hexaaza-2,5,10,12-tetraoxo-7,14-diphenyl-cyclotetradecane(L),has been synthesized.Mn(II),Co(II),Ni(II)and Cu(II)complexes of this ligand have been prepared and subjected to elemental analyses,molar conductance measurements,magnetic susceptibility measurements,mass,1H-n.m.r.(Ligand),i.r.,electronic,and e.p.r.spectral studies.On the basis of molar con ductance the Mn(II),Co(II)and Cu(II)complexes may be formulated as[M(L)X2][where X=Cl&NQ3-]due to their non-electrolytic nature in dimethylformamide(DMF).Whereas the Ni(II)complexes are 1:2 electrolytes and formulated as[Ni(L)]X2.All the complexes are of the high spin type and are six/four coordinate.On the basis of i.r.,electronic and e.p.r.spectral studies an octahedral geometry has been assigned to Mn(II)and Co(II),square planar for Ni(II)complexes,and tetragonal for Cu(II)complexes.The antimicrobial activities of the ligand and its complexes,as growth inhibiting agents,have been screened in vitro against several species of bacteria and plant pathogenic fungi.