The use of mononuclear Cu(II) 2,2'-bipyridine and 1,10-phenantroline complexes as catalysts in the oxidation of benzene, using hydrogen peroxide and tert-butyl hydroperoxide as oxidant in CH3CN/H2O solution is presented. The reactions were carried out at 25 and at 50 A degrees C. The complexes [Cu(bipy)(3)]Cl-2 center dot A 6H(2)O (1), [Cu(bipy)(2)Cl]Cl center dot A 5H(2)O (2), [Cu(bipy)Cl-2] (3), [Cu(phen)(3)]Cl-2 center dot A 7H(2)O (4), [Cu(phen)(2)Cl]Cl center dot A 5H(2)O (5), [Cu(phen)Cl-2] (6) were able to oxidize benzene into phenol, hydroquinone and p-benzoquinone. Highest conversion (22%) was obtained using [Cu(Phen)Cl-2] (6) as catalyst.