Abstract
A new copper(II) complex of an unsymmetrical tripodal ligand (NN2O222) derived from tris(2-aminoethylamine)amine (tren) by substitution of one aminoethyl group by an hydroxyethyl group has been synthesized and characterized by X-ray crystallographic methods as [(NN2O222)Cu(ImH)](ClO4)2·0.5H2O (NN2O222 = 2-[bis(2-aminoethyl)amino]ethanol; ImH = imidazole). Crystals of the complex are orthorhombic, space group Pna21, with a = 29.983(10), b = 15.568(5), c = 8.127(3) Å. Two similar monometallic cations exist in the asymmetric unit and in each case the Cu(II) ion is five-coordinate with tetragonally distorted trigonal bipyramidal geometry. Variable-temperature magnetic measurements show that there is very weak antiferromagnetic interaction between the metal ions. Cyclic voltammetry indicates quasi-reversible CuII/CuI redox behavior at +44 mV vs SCE. An antimicrobial activity study found that the complex is active against Candida albican, Staphylococcus aureus, Bacillus pumilus, Klebosiella pneumoniae and Escherichia coli, but to no greater extent than Cu(ClO4)2·6H2O.
Acknowledgements
This project was supported by the National Natural Science Foundation of China (No. 50372028).