An oxidative coupling reaction intermediate, a mu-OCH3-bridged dinuclear(II) complex [CU2(mu-OCH3)(mu-OAC)(mu-CH3OH)(ClO4)Bipy(2)]-(ClO4) has been synthesized and characterized crystallographically and spectroscopically. This complex crystallizes in the monoclinic space group P2/n, with cell constants a = 7.914(2) Angstrom, b = 11.434(3) Angstrom, c = 34.336(10) Angstrom, alpha = 90, beta = 92.035(5), gamma = 90, V = 3105.3(14) Angstrom(3) and Z = 4. The dicopper(II) complex was investigated in the oxidative coupling reaction of 2,6-dimethylphenol (DMP) to polyphenylene ether (PPE) and shown to function as an effective catalyst. The product yield of 70% and PPE selectivity near 99% were achieved. (C) 2003 Elsevier B.V. All rights reserved.