Synthesis, structure, characterization and theoretical studies of NLO active furan-2-carbohydrazide monohydrate derivative single crystals

Abstract

Single crystals of (E)-N′-(4-isopropylbenzylidene)furan-2-carbohydrazide monohydrate were grown by the slow evaporation solution growth technique from ethanol at room temperature. The crystals belong to the orthorhombic system with noncentrosymmetric space group P2₁2₁2₁. The crystallinity of the material was confirmed by powder X-ray diffraction analysis. The functional groups present in the molecule are identified by FT-IR analysis and the band gap energy is estimated using diffuse reflectance data by the application of Kubelka–Munk algorithm. Theoretical calculations were performed using a density functional theory (DFT) method to derive the optimized geometry, dipole moment, polarizability, HOMO–LUMO energies at different levels, molecular electrostatic potential, excited state energy, oscillator strength, Mulliken charge population and first-order molecular hyperpolarizability, (β) (>58 times of urea). The intermolecular hydrogen bonding interactions are analyzed by Hirshfeld surface analysis and fingerprint plots. The second harmonic generation efficiency (SHG) is estimated using the Kurtz and Perry powder technique and it reveals NLO (nonlinear optical) character. As-grown crystals were further characterized by NMR, mass spectrometry and elemental analysis.