Metal-ion directed synthesis of binuclear octaazamacrocyclic complexes of manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) and their physico-chemical studies

Abstract

A novel series of 16-membered binuclear complexes of octaazatetraimine ligand, ½M 2 LX 4 [M = Mn II , Co II , Ni II , Cu II and Zn II ; X = Cl or NO 3 ] have been synthesized by metal template condensation reactions of o-phenylenediamine with N,N¢-diacetylhydrazine in 1:1:1 molar ratio in methanol. The proposed stoichiometry and the bonding of the macrocyclic moiety to metal ions along with the overall stereochemistry have been derived from the results of elemental analyses, magnetic susceptibility, conductivity data and the spectral data revealed from FT-IR, 1 H-NMR , ESI mass, UV-visible studies. An octahedral geometry has been envisaged for Mn II , Co II , and Ni II complexes while a slight distortion in octahedral geometry has been noticed for Cu II complexes. The low conductivity data of all the complexes suggest their non-ionic nature.

<b>Spectral characterizations and antibacterial effect of 2-(5-R-1<i>H</i>-benzimidazol-2-YL)-4-methyl/bromo-phenols and some metal complexes</b>

“…These results are indicative for 1:1 electrolytes. The other complexes have non-ionic character according to the molar conductivity values [14,15].…”

Synthesis and characterization of Schiff base metal complexes derived from Napthofuran-2-Carbohydrazide and 4-(methylthio)benzaldehyde

“…This value for nickel complex is 2.859 B.M., which is slightly greater than a spin-only value (2.83 B.M. ), demonstrating an octahedral structural environment [22][23][24]. The copper complex displays a magnetic moment value of about 1.87 indicating a deformed octahedral geometry [25].…”