Copper(II) complexes of usnic acid condensation products and their antibacterial activities

The complexes of Cu(II) and condensation products of usnic acid with the ac yl hydrazides of alpha-naphthoic, caprylic and oxamic acid, as well as the- derivative of usnic acid with thiosemicarbazide have been synthesized and c haracterized by elemental analyses, molar conductivity, magnetic moment mea surements and IR spectroscopy. It was found that the derivatives act as tri dentates occupying three coordination places in the square planar molecules with the fourth coordination site occupied by a solvent molecule. The comp lexes were tested for in vitro growth inhibitory activity against the bacte rial species Escherichia coli and Staphylococcus aureus. The complexes have higher antibacterial activities compared to both the usnic acid derivative s and Cu(II) ions.