Synthesis, Crystal Growth, Structure, Crystalline Perfection, Thermal, Linear and Nonlinear Optical Investigations on 2-Amino-5-Nitropyridine 4-Chlorobenzoic Acid (1:1): A Novel Organic Single Crystal for NLO and Optical Limiting Optical Applications

Abstract

2-amino-5-nitropyridine 4-chlorobenzoic acid (1:1) (2A5NP4CBA), a potentially useful organic adduct compound has been synthesized and grown as optically transparent single crystals by conventional slow evaporation solution technique (SEST) for the first time in the literature. The formation of the new crystalline material was confirmed by the single-crystal X-ray diffraction (SXRD) analysis and the crystal structure of the grown crystal was found to be monoclinic. Fourier transform infrared (FTIR) spectrum has been recorded by the KBr pellet technique to determine the various vibrational functional groups in the title material. The powder X-ray diffraction (PXRD) and high-resolution X-ray diffraction (HRXRD) analyses have been carried out and the obtained results reveal that the grown crystal has a single-phase and is free from structural grain boundaries. The obtained less value (32 arc-s) of full width at half maximum (FWHM) for (001) plane indicates the excellent crystalline quality of the title 2A5NP4CBA single crystal. The linear optical properties were evaluated by the UV-vis-NIR absorption and transmittance analyses and the obtained results reveal that the grown crystal possesses more than 70% of optical transmittance window with the cut-off edge at 419 nm. The thermal analysis discloses that the grown crystal possesses good thermal stability of about 187°C. To determine the appropriateness of the grown crystal for the high-power laser application, laser damage threshold (LDT) analysis has been carried out by Nd: YAG laser of a wavelength of 1064 nm. The third-order nonlinear optical coefficients such as nonlinear absorption (β), nonlinear refraction (n 2 ) and nonlinear susceptibility (χ (3) ) have been evaluated by utilizing the single beam Z-scan technique using a solid-state laser of wavelength 532 nm. The calculated ꭓ (3) value is found to be reasonably good compared to other organic single crystals which are reported in the literature. The optical limiting (OL) behavior of the title crystal was evaluated using a solid-state laser at 532 nm and the limiting threshold was found to be 7.8 mW/cm 2 .