The catalytic epoxidation of styrene using ureahydrogen peroxide and heterotrinuclear Cu(II) complexes with general formula (MLn)2Cu(acac)2, where n = 1–3 and M = VO2? or Mn2? is reported. Schiff base complexes MLn involving a 3,4-diaminopyridine bridge with free coordination site were used as the ligand, where (Ln)2- is [(5-x-Sal)2Py]2 and x = H, Br or NO2. The complexes were characterized by physico-chemical and spectroscopic methods. The electrochemical properties of M were modified upon trinuclear complex formation. The trinuclear complexes show high catalytic activity, with up to 86% conversion and 93% selectivity, while no catalytic properties were observed for the monomeric complexes. The catalyst could be reused with some loss of activity.
