Effect of pH, thermal, electrical and thermomechanical properties of nonlinear optical L-threonine single crystals.

Nonlinear optical L-threonine single crystals have been grown at various pH values. The crystals were subjected to dielectric and thermomechanical measurements at various temperatures. The thermal strength of the grown crystal was also determined by differential scanning calorimetry (DSC) analysis. The results have been discussed in detail.

Structural, spectral, linear and nonlinear optical properties of new nonlinear optical L-histidinium trichloroacetate crystals.

Single crystals of a new histidinium salt: L-histidinium trichloroacetate {abbreviated as LHTCA; [(C(3)N(2)H(4))CH(2)CH(NH(3))(CO(2))](+)CCl(3)COO(-)} were grown by slow evaporation of an aqueous solution at room temperature. The compound crystallizes in a non-centrosymmetric space group P2(1) of monoclinic system with cell parameters a=5.4505(18) A, b=25.769(8) A, c=9.210(2) A and beta=99.98(2) degrees. The vibrational structure of the compound confirms the presence of various functional groups in the molecule. The UV-vis-NIR spectrum shows a good transparency in the whole of the region from ultraviolet to near IR. The Kurtz powder SHG measurement confirms the frequency doubling of the crystal. Thermal behaviour of the crystals has been investigated by DSC analysis. These preliminary results suggest that LHTCA crystal can act as a potential and promising candidate for frequency doubling applications even from the near UV region to the near IR.