Synthesis, growth, spectral studies, first-order molecular hyperpolarizability and Hirshfeld surface analysis of isonicotinohydrazide single crystals

Abstract

Single crystals of (E)-N′-((4-fluorophenyl)(phenyl)methylene)isonicotinohydrazide dihydrate were grown by the slow evaporation solution growth technique. The structure was elucidated by single crystal X-ray diffraction analysis and the crystal belongs to the triclinic system with the space group P. The crystallinity of the material was confirmed by powder X-ray diffraction which coincides well with the simulated pattern with varied intensities. The band gap energy is estimated by the application of the Kubelka–Munk algorithm. Theoretical calculations were performed using density functional theory (DFT), to derive the optimized geometry, dipole moment, HOMO–LUMO energies and first-order molecular hyperpolarizability, β (∼84 times that of urea). The energy and oscillator strengths calculated by TD-DFT results complement the experimental findings. The atomic charge distributions of the various atoms were obtained by Mulliken charge population analysis. The molecular stability and bond strength were investigated by applying natural bond orbital analysis. Investigation of the intermolecular interactions and crystal packing via Hirshfeld surface analysis, based on single-crystal XRD, reveals that the close contacts are associated with molecular interactions. Fingerprint plots of the Hirshfeld surfaces were used to locate and analyze the percentage of hydrogen-bonding interactions. The grown crystals were further characterized by FT-IR, FT-Raman and TG/DTA.