Electron spin resonance and optical absorption studies are carried out on bis (8- hydroxyquinolinato) copper (II) and seven ternary copper (II) complexes with 8- hydroxyquinoline and salicylic acid or substituted salicylic acids. Electron spin resonance spectra of all these complexes give well-resolved lines. An unusual splitting of the parallel lines in frozen solution spectra and four line fluid (DMF) solution spectra at room ...