Abstract

A new organic NLO crystal, 4-methylimidazolium phthalate monohydrate (4MIPM), was synthesized and grown by the slow evaporation method. Single-crystal X-ray diffraction analysis verified the formation of the new crystalline material, which was deposited in CCDC number 2417,091. The Rietveld refinement confirms that the Bragg positions are well-fitted with the diffraction peaks, suggesting phase purity and crystallinity. The IR spectrum of 4-methylimidazole, phthalic acid and 4MIPM crystals were recorded. The changes that exist due to interactions have been discussed. The grown crystal was thermally stable up to 100 degrees C, with decomposition initiating near 200 degrees C. Optical transmittance studies confirmed that 84 % were in the visible and near-infrared regions. The optimized structure of 4MIPM has been optimized using the DFT/B3LYP method with a 6-311++G (d,p) basis set. The crystal structure of 4MIPM is stabilized by an H-boding network involving the 4-methylimidazolium cation, phthalate anion and water molecules. The global chemical reactivity descriptor properties were studied by HOMO-LUMO analysis. In addition, the structural analysis was done by Mulliken atomic charge, NBO, molecular hyperpolarizability and electrostatic potential analysis. The third-order NLO parameters were evaluated using Z-scan analysis.