Synthesis, EPR and biological activities of bis(1-n-butylamidino-O-alkylurea)copper(II)chloride complexes: EPR evidence for binuclear complexes in frozen DMF solution

The EPR spectra of copper(II) complexes of the type [Cu(1-BunAAUH)2]Cl2, where 1-BunAAUH = 1-n-butylamidino-O-alkylurea, in frozen solutions of DMF showed a signal at g ca. 2. In addition to this, a signal at half the resonance field having a well resolved seven-line hyperfine structure was observed, which have been interpreted as arising from ΔMs = ±1 and ΔMs = ±2 transitions. The complexes show growth inhibitory activity against pathogenic fungi and bacteria.