Spectroscopic studies of 4-(4,6-dimethylpyrimidin-2-ylazo) benzene-1,3-diol and its Cu(II) complexes. - Gaber M; Fayed TA; El-Daly S; El-Sayed YS (Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy, 2007)