New lanthanum coordination complex with high second harmonic generation: Growth, crystal structure and physicochemical characterization

Abstract

Coordination complexes represent one of the most investigated and used non-linear optic materials thanks to the metal center's ability to provide a wide range of non-linear optical structures. Thus, the present paper is interested in the growth of a novel organometallic nonlinear-optical crystal, Bis(4-aminobenzenesulfonate)triaquatrinitrato lanthanum (III) (4ABTATNL),[La(C6H6NSO3H)2(NO3)3(H2O)3] from an aqueous solution via slow evaporation method. Next, its structural, thermal and non-linear optical properties were assessed using X-ray diffraction (XRD), UV–Visible, Fourier transformed infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDX), Thermo-gravimetric analysis (TGA), and Second Harmonic Generation (SHG). It was discovered from XRD, that the title compound adheres to the monoclinic crystallographic system with the centrosymmetric space group P21/c. Its UV wavelength corresponding to the absorption at 248 nm revealed a good optical transparency. Regarding the FT-IR spectrum, it identified the characteristic absorption bands. As for the stability of the organometallic crystal, it was also evaluated by means of the thermo-gravimetric analysis (TGA). With respect to the second-order nonlinear optical (NLO) property of 4ABTATNL complex, it was determined by Kurtz-Perry technique. The crystalline KDP was used as a comparative material for the SHG measurements. It was found that efficiency SHG exhibited about 1.28 times than crystal KDP. Besides, the values of initial hyperpolarizability and polarizability were calculated in order to assess the nonlinear optical behavior of the examined compounds.