Physical and theoretical investigations on piperazinium 3,5-dinitrobenzoate (PDNB) single crystal: A potential candidate for third-order nonlinear optical (NLO) applications

Abstract

A potential third-order nonlinear optical (NLO) material of piperazinium 3,5-dinitrobenzoate (PDNB) has been synthesized from the pure aqueous solution through protonation reaction and its single crystals have been successfully grown by slow evaporation solution technique (SEST) within a span of 75 days. The structural properties of the grown single crystals have been evaluated by single-crystal X-ray diffraction (SXRD) analysis. It reveals that the grown crystal crystallizes in a triclinic crystal system with centrosymmetric space group Pī. The existence of various crystalline planes and phase purity of the title material were confirmed by powder X-ray diffraction (PXRD) analysis with the 2θ scanning range of 10° to 50° The proton (1H1) nuclear magnetic resonance (NMR) spectrum has been recorded to elucidate the molecular structure of the synthesized PDNB material. The presence of multiple functional groups and optical properties of the title material have been evaluated by Fourier transform infrared (FT–IR) and UV–Vis NIR spectroscopy analyses, respectively. The photoluminescence property of the PDNB crystal has been examined by the excitation and emission spectra. The grown crystal possesses good thermal stability (stable upto 197 °C), which is determined by thermogravimetric (TG) and differential thermal analysis (DTA). The grown crystal possesses excellent third-order NLO property when irradiation of He-Ne laser of wavelength 632.8 nm. Theoretical investigations such as optimized geometry, HOMO-LUMO, first-order hyperpolarizability and Hirshfeld surface analyses have been carried out and their interesting results have been discussed. The overall experimental and theoretical results lead to conclude that the title PDNB single crystal is a potential candidate for the NLO and optoelectronic applications.