Experimental and theoretical studies of the second- and third-order NLO properties of a semi-organic compound: 6-Aminoquinolinium iodide monohydrate

A new semi-organic compound, 6-aminoquinolinium iodide monohydrate (I), has been synthesized and characterized by single crystal X-ray diffraction, UV-vis absorption and fluorescence spectroscopy and nonlinear optical (NLO) measurements. The second-and third-order NLO responses were investigated with the second-and third-harmonic Maker fringes techniques, carried out on thin films at a fundamental wavelength of 1064 nm. From the molecular structure, the molecular hyperpolarizability tensors were determined with density functional theory and second-order Moller-Plesset perturbation method. The second-and third-order susceptibility tensors of the reported crystal were evaluated using the oriented gas model with the Lorenz-Lorentz and the Wortmann-Bishop local-field corrections. The calculations using the Wortmann-Bishop local-field were able to reproduce the correct order of magnitude of the experimental third-order susceptibilities. The value of chi((3)) obtained by summing the effective third-order polarizability calculated for the asymmetric unit surrounded by ESP-derived charges have also the same order of magnitude of the experimental. (C) 2013 Elsevier B. V. All rights reserved.