Synthesis, Structural, Spectroscopic and Quantum Chemical Investigation of a Novel 1,4-Diamino-2,5-dichlorobenzenium Picrate Single Crystal: An Efficient NLO Material

A new organic nonlinear optical single crystal, 1,4-diamino-2,5-dichlorobenzenium picrate (DADCBP) has been successfully grown by solvent slow evaporation method. DADCBP crystallizes in a triclinic structure with the centrosymmetric space setup, P-1. The molecular structure of the grown crystal has been determined by NMR spectral analysis. The existence of discrete functional branches of the crystal has been identified by FTIR spectral study. The optical property of the title crystal has been measured by UV-Vis-NIR spectral analysis. PL spectra reveal the emission bands of the grown crystal. The thermal stability of the harvested crystal has been examined by the TG/DTA study. The dielectric constant and loss have been taken to locate the arrangement of charges in the grown crystal. The quantum chemical studies have been performed to analyze the HOMO/LUMO, molecular geometry, and mulliken atomic charge by B3LYP at the 6-311++G (d,p) level of theory. H···H, O···H, C···H, C···C various intermolecular interactions of hydrogen bonds in the DADCBP molecule have been visualized by the Hirshfeld surface analysis. The nonlinear optical (NLO) characteristics like nonlinear absorption coefficient (β), nonlinear refractive index (n₂) and susceptibility (χ⁽³⁾) have been examined using the Z-scan technique.