Spectroscopic, quantum-chemical and X-ray diffraction studies of Piperidinium p-Hydroxybenzoate-combined experimental and theoretical studies on a novel NLO crystal

Photoluminescence, Third-Order Nonlinear Optical and DFT Studies of Hydrazonium L-Tartrate – Combined Experimental and Theoretical Studies

Isothermal solvent evaporation method was employed to grow Undeuterated Hydrazonium L-tartrate (HLT) single crystals using water:methanol (5:1) solution as a solvent. The proton and carbon positions of HLT have been revealed by 1H and 13C NMR spectrum, respectively. The energy emission behaviour of HLT were analysed by photoluminescence spectrum. The nonlinear refractive index (n2), nonlinear absorption coefficient (β) and third order nonlinear susceptibility (χ 3) of HLT single crystal were determined by adapting Z-scan technique. Quantum chemical calculations on HLT was carried out by DFT using B3LYP/6-311++G(d,p) basis set. The predicted first hyperpolarizability of HLT is found to be 1.09 times greater than that of urea and suggests that HLT could be an attractive material for NLO applications. The predicted HOMO-LUMO energies of HLT confirmed that charge transfers occur within the molecule. The molecular bond strength and stability of the title compound were analysed by employing NBO analysis. The other molecular properties such as Mulliken atomic charge, ESP map, thermodynamic functions and perturbation theory energy have also been investigated. These investigations have been carried out for the first time, to the best our knowledge, in order to study the nonlinear optical properties of HLT and to enhance its usefulness for NLO applications.

Spectroscopic, Quantum Chemical, Physical and Antioxidant Studies on 2-Amino 4-Picolinium 4-Nitrobenzoate – An Organic Crystal for Nonlinear Optical and Biological Applications

The title compound, 2-amino 4-picolinium 4-nitrobenzoate (2A4PNB), has been identified as a nonlinear optical material and its good quality single crystals were grown from methanol solution. It crystallizes in monoclinic system with the non-centro symmetric space group Pc. Its structure and chemical compositions were confirmed by the X-ray diffraction and microanalysis studies, respectively. FTIR, UV-Visible-NIR, NMR and photoluminescence (PL) spectra have been recorded and extensive spectroscopic investigations have been carried out. The grown crystals have been subjected to micro hardness and photoconductivity studies to explore its physico chemical properties. The free radical scavenging activity of the complex has been determined against DPPH and H2O2 radicals. In addition, the quantum chemical studies were performed on the isolated 2A4PNB molecule using DFT calculations at the B3LYP/6-311++G (d,p) basis set.

Spectroscopic, nonlinear optical and quantum chemical studies on Pyrrolidinium p-Hydroxybenzoate--a phase matchable organic NLO crystal

Good quality and bulk single crystals of Pyrrolidinium p-Hydroxybenzoate (PYPHB), a newly identified nonlinear optical material, were grown for the first time. It crystallizes in monoclinic system with an acentric space group Cc. The molecular structure including carbon, proton positions and functional groups has been confirmed through nuclear magnetic resonance and Fourier transform infrared spectra. Its transmission window has been observed for UV-VIS-NIR region along with its theoretical limit. The photoluminescence behavior has been observed by exciting the crystal at 310 nm. The principal refractive indices and second order NLO coefficient of PYPHB are determined by Mach-Zehnder interferometer and Maker-Fringe experiments respectively. The coherence length and phase-matchablility of PYPHB crystals are measured to explore its efficacy towards device fabrications. The dipole moment, polarizability and molecular orbital energy of an isolated PYPHB molecule have also been calculated theoretically and the results are found to corroborate the experimental values.