Vibrational spectra, dielectric properties, conductivity mechanisms and third order nonlinear optical properties of guanidinium 4-aminobenzoate

Abstract

The frequency response of dielectric permittivity measurements at temperatures 35 °C and 100 °C suggests enhanced inherent optical quality and few defects in the crystal. The Cole-Cole plot shows the presence of grain and grain boundary, it is found that single relaxation is observed in the crystal. The ac and dc conductivity and dielectric behavior of the grown crystal were systemically investigated as a function of frequency and temperature. The third order nonlinear optical property extensively studied by z-scan technique revealed high third order nonlinearity in the form of self-defocusing and two-photon absorption with saturable absorption. The strong intermolecular charge transfer interaction evident from NBO and AIM studies confirms the NLO property of the material. The detailed vibrational assignments were carried out on the basis of potential energy distribution (PED) analysis and scaled quantum mechanical force field calculation using MOLVIB program. The red shifted NH stretching wavenumbers and the broadening of corresponding bands in the solid state as well as the gas phase spectra, optimized molecular geometry and NBO analysis have confirmed the presence of N-H⋯O hydrogen bonding in G4AB.