Crystal growth, spectral, Hirshfeld surface analysis, and physicochemical properties of third-order non-linear optical single crystal: 2-methylimidazolium hydrogen adipate

Abstract

A non-linear organic optical material, 2-methylimidazolium hydrogen adipate (2MIA) crystal, was developed by a slow-evaporation solution growth method. An X-ray diffraction analysis of a single crystal was used to assess the parameters of unit cells and space groups. Powder X-ray diffraction analysis was used to examine the crystal structure and purity of the crystalline planes. The Williamson—Hall equation was used to get the lattice strain in each plane from the PXRD spectra. The 2MIA compound was examined with vibrational bands using Fourier transform infrared spectroscopy. The NMR spectra were used to validate the existence of proton and carbon atoms in the grown single crystal. The percentage contribution of hydrogen interaction of 2MIA was analyzed by a fingerprint plot calculated from the Hirshfeld analysis. We evaluated the optical transparency, and the band gap of the 2MIA single crystal was evaluated from UV-Vis spectroscopy. The thermal property of the 2MIA single crystal was analyzed by TG/DTA technique. The Vickers microhardness test calculated the mechanical properties of 2MIA single crystals for various loads and belonged to the soft category. The dielectric behavior of formed crystals has been investigated for different temperatures regarding frequencies. Optical parameters of the third-order non-linear, such as non-linear refractive index (n2), non-linear absorption coefficient (β), and third-order non-linear susceptibility (χ3), have been determined using Z scan studies.