Synthesis, growth and characterization of nonlinear optical crystal: propylenediamine picrate (PDP) single crystals

Abstract

In this study, slow evaporation technique is used for the growth of organic single crystal of Propylenediamine Picrate (PDP) and this research investigates crystallographic, experimental, and theoretical density functional theory (DFT) of PDP. The crystal structure was found from single-crystal XRD analysis. Spectral analyses, including UV–Vis and FTIR spectroscopy, revealed a bandgap energy of 3.505 eV and identified key functional groups. The SHG efficiency of the crystal is measured to study the NLO property of the crystal. The (SHG) efficiency was measured as 0.53 that of KDP, confirming the nonlinear optical (NLO) properties. Thermal stability was evaluated using TG/DTA, and the crystal’s mechanical hardness was measured as 2.753 via Vickers microhardness testing. Dielectric properties, including loss, permittivity, and AC conductivity, were examined at varying temperatures. The first-order hyperpolarizability (β0) and related properties (β, α0, and Δα) of PDP is calculated usingB3LYP/6-31G (d,p) method on the finite field approach. The study reveals that the transfer of charge occurs within these molecules through the analysis of the molecular structure of PDP, performed using the molecular electrostatic potential (MESP) and calculated HOMO and LUMO energies. The study confirms PDP’s potential in optoelectronic applications.