Synthesis, Hirshfeld surface analysis, DFT calculations, photoluminescence, spectroscopic and second order non linear optical studies on ammonium hydrogensquarate squaric acid monohydrate crystal

Abstract

A new nonlinear optical material, Ammonium hydrogensquarate squaric acid monohydrate (AHSAM) has been synthesized. Single crystals of AHSAM have been grown successfully by slow evaporation solution technique (SEST). The grown AHSAM crystals have been subjected to Single crystal X-ray diffraction analysis (XRD), Hirshfeld surface analysis, Fourier transform infrared spectroscopy (FT-IR), Fourier transform Raman (FT-R) spectroscopy, Calculated and experimental ultraviolet–visible spectral analysis, Photoluminescence, Microhardness and second harmonic generation (SHG). From X-ray diffraction studies it shows that the structure belongs to monoclinic structure with space group C2/c. Hirshfeld surface analysis used to clarify the intra and intermolecular interactions in a visual manner. The molecular geometries are compared with AM1, HF and Density Functional Theory calculations and it shows good agreement with experimental data. The Frontier molecular orbital energy gap is found by TD-DFT method with HOMO-LUMO calculation. The second order NLO studies for AHSAM crystal is done by Kurtz and Perry powder technique.