Synthesis, structural, thermal, mechanical, laser damage threshold and DFT investigations on bis (2-methylimidazolium-4-aminobenzoate) single crystal

Abstract

An organic salt, bis (2-methylimidazolium-4-aminobenzoate) (MIAB) was synthesized and single crystals grown successfully by slow solvent evaporation solution growth technique using ethyl acetate as solvent at room temperature. Fourier transform infrared (FTIR) spectral analysis was carried out to detect the presence of functional groups in the MIAB salt crystal. 1H and 13C spectra were recorded to confirm the presence of various kinds of proton and carbon environments thereby establish the molecular structure of MIAB crystal. Single crystal X-ray diffraction analysis (SCXRD) reveal that the crystal belongs to monoclinic system centrosymmetric space group, P21/c. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) confirms that the MIAB crystal is thermally stable up to 250 °C. The mechanical properties of the grown crystal were determined by Vickers Microhardness test. Computational studies were performed using Gaussian 09 software by 6.31 g basis set level. The calculated first order hyperpolarizability (β) of MIAB from computational studies is 5.01 times that of Potassium dihydrogen phosphate (KDP). The laser damage threshold value of the MIAB is found to be 1.44 GW/cm2. Z-scan technique reveals the optical non-linearity of the crystal.