Synthesis and Third-Order Nonlinear Optical Properties of Copper and Nickel Coordination Complexes of Azo Dyes

Abstract

An azo dye, 2-(4,5-dicyano-1-H-imidazolyazo)-5-N, N-diethylaminophenol, and the corresponding divalent copper and nickel mononuclear coordination complexes were synthesized. The molecular third-order nonlinear optical characteristics of these azo transition metallic chelates were investigated in N,N′-dimethylformamide solution using a standard Z-scan technique with a 7-ns laser pulses at 1,064 nm. The results of n 2 (the nonlinear refraction index) and γ (the hyperpolarizability) values of the two complexes indicated that metal chelating lead to considerable enhancement in third-order optical nonlinearities, which revealed that such coordination complexes exhibit strong nonlinear optical absorption effects and self-defocusing performance. These materials are promising candidates as large third-order nonlinear optical materials.