Second-order non-linear optical properties of Langmuir–Blodgett films of a new azo compound(p-NO2)C6H4N NC10H6O(CH2)3N(CH3)2C18H37Br and its europium complex

Abstract

A new azo compound, N,N,N-dimethyloctadecyl-3-{[4-(4-nitrophenylazo)]-l-naphthoxy}propyl quarternary ammonium bromide and its europium complex have been synthesized and their second-order non-linear optical properties have been investigated. The molecular hyperpolarizabilities, β were evaluated to be 2.55 × 10^–28 and 2.95 × 10^–28 esu, respectively. Data show that both compounds have good film formation properties. A quadratic relationship between the SHG signal and the number of layers was obtained in the complex with a large rare-earth-metal complex anion. These novel compounds provide new possibilities for designing high-quantity second-order non-linear optical materials to solve the quadratic SHG enhancement in LB films.