Synthesis, crystal growth, structural, thermal, optical and mechanical properties of solution grown 4-methylpyridinium 4-hydroxybenzoate single crystal.

Organic nonlinear optical material, 4-methylpyridinium 4-hydroxybenzoate (4MPHB) was synthesized and single crystal was grown by slow evaporation solution growth method. Single crystal and powder X-ray diffraction analyses confirm the structure and crystalline perfection of 4MPHB crystal. Infrared, Raman and NMR spectroscopy techniques were used to elucidate the functional groups present in the compound. TG-DTA analysis was carried out in nitrogen atmosphere to study the decomposition stages, endothermic and exothermic reactions. UV-visible and Photoluminescence spectra were recorded for the grown crystal to estimate the transmittance and band gap energy respectively. Linear refractive index, birefringence, and SHG efficiency of the grown crystal were studied. Laser induced surface damage threshold and mechanical properties of grown crystal were studied to assess the suitability of the grown crystals for device applications.

4-(4-Bromo-styr-yl)-1-methylpyridinium tosyl-ate.

In the cation of the title compound, C14H13BrN(+)·C7H7O3S(-), the dihedral angle between the benzene and pyridine rings is 8.34 (11)°. The Br atom is disordered over two positions with site occupancies of 0.74 (2) and 0.26 (2). The mol-ecular structure is stabilized by a weak intra-molecular C-H⋯O inter-actions. The crystal structure exhibits weak C-H⋯O and π-π [centroid-centroid distance = 3.7466 (17) Å] inter-actions, forming a three dimensional network.

2-Phenyl-ethanaminium 4-hy-droxy-benzoate.

In the title salt, C8H12N(+)·C7H5O3 (-), the cation is disordered over two orientations with site occupancies of 0.565 (7) and 0.435 (7). In the anion, the carboxyl-ate group makes the dihedral angle of 4.19 (18)° with the benzene ring. In the crystal, the ions are connected by N-H⋯O and O-H⋯O hydrogen bonds, forming a three-dimensional network.

4-Methyl-pyridinium 4-hy-droxy-benzoate.

In the crystal structure of the title salt, C(6)H(8)N(+)·C(7)H(5)O(3) (-), the anions and cations are linked by classical N-H⋯O hydrogen bonds. The anions are connected by pairs of C-H⋯O hydrogen bonds into inversion dimers and further linked by classical O-H⋯O hydrogen bonds. Weak π-π inter-actions [centroid-centroid distances = 3.740 (3) and 3.855 (3) Å] also occur. The dihedral angle between the CO(2) (-) group and the benzene ring to which it is attached is 20.95 (8)°.

Dimethyl-ammonium 4-hy-droxy-benzoate.

In the crystal structure of the title compound, C(2)H(8)N(+)·C(7)H(5)O(3) (-), the anions and cations are linked by O-H⋯O and N-H⋯O hydrogen bonds into layers parallel to the ac plane.

Growth, structural, thermal, linear and nonlinear optical and laser damage threshold studies of picolinium tartrate monohydrate single crystals.

Picolinium tartrate monohydrate (PTM), a novel organic nonlinear optical material was synthesized and bulk crystals were grown from aqueous solution by slow cooling technique. The cell parameters of the grown crystal were found by single and powder X-ray diffraction analyses. The crystalline perfection of the grown crystals has been analyzed by high-resolution X-ray diffraction (HRXRD) rocking curve measurements. The presence of functional groups in the grown crystal was identified by FTIR and FT-Raman spectral analyses. UV-Vis spectral studies reveal PTM crystals are transparent in the wavelength region of 295-1100 nm. The thermal characteristics of PTM were analyzed by TGA/DTA studies. The dielectric and mechanical behaviours of PTM crystals were investigated. Dislocation density was estimated to be 2.89 × 10(3) cm(-2) on the flat-surface of PTM crystals from the etching studies. The laser induced surface damage threshold for the grown crystal was measured using Nd:YAG laser. Its second harmonic generation relative efficiency was measured by Kurtz and Perry powder technique and was observed to be comparable with KDP crystal.