Growth, molecular structure, NBO analysis and vibrational spectral analysis of l-tartaric acid single crystal.

Single crystal of l-tartaric acid (LTA) has been grown by slow evaporation technique. The experimental and theoretical studies on molecular structure, vibrational spectra, electronic absorption spectra and non-linear optical property of the crystal are studied. The FT-IR, FT-Raman and UV-Vis-NIR experimental spectra of LTA crystal have been recorded in the range 400-4000cm(-1), 100-3700cm(-1) and 190-1100nm, respectively. Density functional theory calculations with B3LYP/6-311++G(d,p) basis sets was used to determine ground state molecular geometries, vibrational frequencies, ICT interactions, Mulliken population analysis on atomic charge, HOMO-LUMO analysis, non-linear optical response properties and thermodynamic properties for LTA and the results were discussed. Vibrational analysis confirms the formation of intramolecular OH⋯O hydrogen bonding. The stability of the molecule has been analyzed using NBO analysis. The results of electronic absorptions in gas phase and water phase LTA were calculated using TD-DFT method. The third-order nonlinear absorption behaviour of LTA was studied using open aperture Z-scan technique, with 5ns laser pulses at 532nm and the nonlinear absorption coefficient of the grown crystal was measured. The predicted NLO properties, UV absorption and Z-scan studies indicate that LTA is an attractive material for laser frequency doubling and optical limiting applications.