Synthesis, crystal structure, spectral characterization and Hirshfeld surface analysis of (E)-N ' -(3-ethoxy-4-hydroxybenzylidene)-4-fluorobenzohydrazide single-crystal-a novel NLO active material

A B S T R A C T (E)-N '-(3-ethoxy-4-hydroxybenzylidene)-4-fluorobenzohydrazide (3E4H4FB) single crystal was obtained by recrystallization method. Single-crystal X-ray diffraction analysis revealed the crystalline structure, packing, and molecular geometry features of the prepared crystal. The structural parameters such as bond distances and angles of 3E4H4FB crystal were discussed. The B3LYP/6-311G(d,p) level of theory was used to do optimize the structure, and the computed results reveal that the optimized geometry can perfectly replicate the crystal structure. The inter-and intramolecular hydrogen bonding interactions were also in-terpreted. Hirshfeld surface analysis was used to elucidate and quantify the intermolecular interactions between the molecules in the crystal structure. FTIR analysis was applied to identify the characteristic functional groups of the synthesized crystal. Natural bond orbital (NBO) and Quantum Theory of Atoms in Molecules (QTAIM) analyzes of the molecule were also used to quantify interactions present in the molecule. The excitation wavelengths, oscillator strengths, and excitation energies were determined by the TD-DFT calculations and compared to the experimental wavelengths. The charge transfer within the molecule was explained by the frontier molecular orbital analysis. Nonlinear optical (NLO) properties were calculated to predict the electric dipole moment and first-order hyperpolarizability of the com-pound. The static third-order susceptibility value was measured by the Z-scan technique. Finally, the eco-toxicity impact of the novel NLO material was assessed towards fish, daphnia, and green algae. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study focused on the crystal structure, bond distances, angles, intermolecular interactions, and optical properties of (E)-N '-(3-ethoxy-4-hydroxybenzylidene)-4-fluorobenzohydrazide (3E4H4FB) single crystal. Various theoretical and analytical methods were used to comprehensively investigate the crystal, and its ecotoxicity impact was also assessed in the ecological environment.