Structure and spectral properties of l-histidinium dipicrate dihydrate

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2014-01, Vol.118, p.102-111
• Main Authors: Sethuram, M., Dhandapani, M., Sethu Raman, M., Amirthaganesan, G., Senthilkumar, K.
• Format: Article
• Language: English
• Subjects: Crystal structure; Density functional theory; FT-IR; FT-Raman; Hyperpolarisability; NLO
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2013.08.080

Single crystals of l-histidinium dihydrate dipicrate (LHDD), a novel organic NLO material, have been grown by solvent evaporation-solution growth technique. LHDD crystals were examined by elemental analysis and spectroscopy analyses such as FT-IR, 1H NMR, 13CNMR and UV–visible. Thermal analyses were carried out to characterise the thermal behaviour and stability of LHDD. The structure of LHDD was optimised by quantum chemical calculation based on Discrete Functional Theory (DFT) using experimental XRD structural data. The energies of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) and first-order hyperpolarisability were calculated. [Display omitted] •Synthesis of single crystals of LHDD by slow evaporation method is reported.•Characterisation was done by TG/DTA, FT-IR, FT-Raman, 1H and 13C NMR spectra.•DFT simulated data were compared with experimental data of FT-IR and XRD data.•MO energy gap calculations were done.•The crystal possesses SHG activity 2.5 times larger than KDP. Non-linear optical active l-histidinium dipicrate dihydrate (LHDD) single crystals were grown by slow evaporation method. The Fourier transform FT-IR, FT-Raman, 1H and 13C NMR spectra of the crystal have been recorded and analysed. The spectral analyses confirm the formation of the compound and the stoichiometry. The geometry and spectral characteristics were examined using the density functional theory (DFT) method, B3LYP with 6-31G(d,p) basis set. The first-order hyperpolarisability, energies of frontier molecular orbitals and the Mulliken population analysis were also calculated. The HOMO–LUMO energy gap value 2.73eV indicates the charge transfer from picrate to histidinium through the hydrogen bond. The second-order NLO properties of the molecule are studied by Kurtz–Perry powder technique. SHG efficiency of the compound is nearly 2.5 times greater than KDP. Theoretical calculations indicate hyperpolarisability of LHDD is 39 times greater than urea. The results show that the title molecule can be used for opto-electronic applications.