Synthesis and characterization of cobalt(II), mckel(II), copper(II) and zinc(II) complexes of N₅, 17,18-membered pentaazamacro-cycles with N₅ donor sets

Abstract

A series of cobalt(Il), nickel(ll), copper(ll) and zinc(ll) complexes incorporating N₅, donor sets have been prepared via. the template condensation of <i>o- </i> aminobenzoic acid with 1,2-dibromoethane or 1,3-dibromo propane in the presence of diethylenetriamine resulting in the formation of pentaazamacrocyclic complexes. The overall geometry and mode of bonding have been confirmed by elemental analysis, IR, ¹H NMR, EPR, electronic spectral studies, conductivity and magnetic susceptibility measurements. An octahedral geometry is proposed for all the complexes, where five coordination sites are occupied by the five amine nitrogens and the sixth by an anion.