Experimental and computational studies of L-tartaric acid single crystal grown at optimized pH

Abstract

The good quality l-tartaric acid (LTA) single crystal of size 12 × 09 × 02 mm3 has been grown by slow solvent evaporation technique by optimizing the pH of aqueous solution. The crystallographic data and crystalline phase of grown LTA crystal has been determined using the powder X-ray diffraction study. The ground state molecular geometry of LTA molecule was optimized by means of CAM-B3LYP/6-31G* level of theory using density functional theory (DFT) approach. The qualitative and quantitative analysis of LTA crystal has been undertaken by means of energy dispersive spectroscopic technique. The UV–visible spectral analysis has been performed to determine the optical transparency of LTA crystal in the range of 190–1100 nm and the optical band gap has been evaluated using the transmittance data. The time dependent-DFT (TDDFT) was employed for calculating the absorption spectrum of the title molecule at B3LYP/6-31G*, CAM-B3LYP/6-31G*, LC-BLYP/6-31G*, M06/6-31G*, PBE1/6-31G* levels of theory. The highest occupied molecular orbital and lowest unoccupied molecular orbital (HOMO-LUMO) energy gap was found to be around 6.02 eV at B3LYP/6-31G* level of theory. The Kurtz-Perry powder test has been undertaken to determine the frequency doubling conversion efficiency of LTA crystal. The laser induced third order nonlinear optical (TONLO) effects occurring in LTA crystal have been evaluated by employing the Z-scan analysis at 640 nm. The phase change in refraction nonlinearity, nature of nonlinear absorption and cubic susceptibility of LTA crystal has been evaluated and their respective magnitudes have been determined. The laser damage threshold of LTA crystal has been investigated using the Nd:YAG laser operative at 1064 nm. The frequency response of dielectric constant and dielectric loss of LTA crystal has been investigated at different temperatures ranging from room temperature to 90 °C. The static dipole moment, polarizability and first hyperpolarizability has been evaluated and compared with standard urea molecule.