Synthesis, Growth, Physicochemical Properties and DFT Calculations on Nonlinear Optical Single Crystal of L-Histidine Dinitrate for Frequency Conversion Applications

Abstract

Single crystals of L-Histidine Dinitrate (LHDN) have been successfully grown by slow solvent evaporation technique at room temperature.  Powder X-Ray diffraction patterns has been recorded and indexed for the analysis of crystalline nature and the lattice parameters of the grown crystals. L-Histidine Dinitrate crystallizes in orthorhombic space group P2¹2¹2¹ and it exhibit second order non-linear optical (NLO) susceptibility due to the intermolecular charge transfer. The functional groups are identified by Fourier transform infrared spectral analysis and compared with theoretical spectrum. The optical transmission range of the LHDN crystal has measured by UV–Vis–NIR studies.  It is observed that the minimum absorption in the entire visible and ultra violet range of 240–1500 nm. From absorption spectra the optical band gap is found to be 4.89 eV. Theoretically Simulated XRD pattern of LHDN single crystal has been carried out. Vibration frequencies are calculated using B3LYP/6-31+G (d,p) and B3LYP/6-311++ G(d, p) . Vibration mode assignments were also compared with the experimental results. The optimized geometrical parameters, fundamental vibrational frequencies, IR intensity, Raman activity, atomic small charges, dipole moment, reduced mass, force constant and other thermodynamic parameters were calculated. The second harmonic generation (SHG) efficiency has been carried out and it reveals the NLO property of the crystals. The HOMO and LUMO analysis were used to determine the charge transfer within the molecule and quantum chemical parameters related to the LHDN compound.