Physicochemical and DFT studies on new organic Bis-(2-amino-6-methylpyridinium) succinate monohydrate good quality single crystal for nonlinear optical applications.

X-ray single-crystal study on the slow evaporation technique grown 2-amino-6-methylpyridinium succinate (2A6MS) exposes its crystal system which belongs to triclinic with centrosymmetric space group P 1 ¯ . A crystal having a dimension of 20 × 8 × 4 mm3 was achieved. 1H NMR spectrum was recorded to investigate the chemical surroundings of various hydrogens in the grown 2A6MS complex and to compliment the X-ray single crystal analysis. FTIR and Raman spectral analyses supported the presence of identified functional groups in the chemical structure. The optical studies by UV–Vis and PL have shown the cut-off wavelength at 348 nm and an occurrence of a high optical emission band at 380 nm under an excitation with 342 nm. The thermal/chemical stability up to 104.3 °C and the absence of phase transformation were confirmed by the TG-DSC study. Vicker's micro hardness test at room temperature and Chemical etching perceived the mechanical property and the grown-in features of the 2A6MS crystal. SHG study confirmed that the grown 2A6MS crystal has SHG which is very well compared with the standard KDP crystal. Density functional theory (DFT) computation was used on B3LYP/6–311++G (d, P) basis set to optimize molecular geometry, HOMO-LUMO energies, Mulliken population analyses, molecular electrostatic potential, NBO, and first order hyperpolarizability. Image 1 • Organic new single crystal of 2-Amino-6-methylpyridinium succinate (2A6MS) belongs to triclinic crystal system with space group P 1 ¯ . • The various quantum mechanical parameters were calculated by density functional theory. • The lower cut-off wavelength (348 nm) and good transmission percentage (81%) of grown crystal was obtained. • 2A6MS crystal belongs to soft category material (n = 2.5). • SHG efficiency of 2A6MS crystal higher than that of KDP crystal. [ABSTRACT FROM AUTHOR]