A novel sandwiched copper(II) complex with the ligand 1,4,7-triazacyclononane has been synthesized and characterized by using X ray diffraction analysis. The results indicate that its crystallographic structure is monoclinic, possessing parameters; P2(1)/c, a = 9.5896(3) angstrom, b = 13.5820(10) angstrom, c = 9.5850(3) angstrom, alpha = 90.00 degrees, beta = 119.3850(10)degrees, gamma = 90.00 degrees, nu = 1087.79(5) angstrom(3), Z = 2, Dx = 1,627 mg cm(-3), R = 0.0560, omega R = 0.1548, F(000) = 550.