A new coordination compound CuL2 was synthesized, and its third-order nonlinear optical properties were investigated by Z-scan technique with 2.5 ps laser pulse at 720 nm. The results indicated that the compound CuL2 exhibited very large nonlinear refraction index n(2) of -4.6 x 10(-3) cm(2)/GW and small nonlinear absorption coefficient beta of 7.1 cm/GW, giving rise to excellent one-photon figure of merit (FOM), W = 2.9, and two-photon FOM, T= 0.11, respectively, implying that the compound is a promising candidate for application in all-optical switching. (C) 2007 Elsevier B.V. All rights reserved.