Vibrational spectra, electronic excited states and magnetic properties of the copper(II) ions in alkylaminoacetylurea complexes

Copper(II) complexes with alkylaminoacetylurea ligands were synthesized and studied by means of IR, Raman, electron absorption and luminescence spectroscopies, as well as by ESR and magnetic methods. The spectroscopic and magnetic studies were performed in the 4-300 K and 1.9-300 K temperature ranges, respectively. The Cu2+ ions in these complexes are four coordinated having distorted squareplanar surroundings. The dependence of the spectroscopic parameters on the alkyl radical of the ligand is discussed. At low temperatures, very weak ferromagnetic interactions are observed for the C3 and C5 alkyls, and an antiferromagnetic one is observed for the remaining complexes, with C4 and C6-C18 alkyls.