Crystal growth, structural and DFT study of novel single crystal (E)-N’-(2-chlorobenzylidene)-4-fluorobenzohydrazide for nonlinear optical applications

Abstract

Nonlinear optical (NLO) material, (E)-N'-(2-chlorobenzylidene)-4-fluorobenzohydrazide (CBBH) novel single crystal was grown via a Schiff base chemical reaction. A single crystal X-ray diffraction technique was utilized for the recognition of the crystal structure of the CBBH. The imperfection of novel CBBH crystal was checked by high resolution X-ray diffraction (HRXRD) study. Hirshfeld surface study through colour coding was applied to know the intra and intermolecular force interactions. Fourier transforms infrared (FTIR), proton 1H and carbon 13C nuclear magnetic resonance (NMR) spectra were employed to elucidate the various functional groups and structure of the crystal. The absorption maxima from UV–Vis plot for the CBBH molecule was found at 314 nm, which reveals the π-π* transition. Photololuminescence (PL) study reveals that emission observed in the blue-violet region. The HOMO and LUMO energies were investigated using the density functional theory (DFT) method. Natural bond orbital (NBO) analysis explored the donor-acceptor exchanges and it's endurance into intra-molecularly. The first-order hyperpolarizability value, β0 = 23.73 × 1030 esu was observed for CBBH crystal, which is ∼64 times larger than that of urea molecule (0.3728 × 1030 esu). Z-scan experiment on CBBH crystal supports its third-order nonlinear optical (NLO) properties. Optical limiting analysis indicates reverse saturation absorption behavior of CBBH crystal.