Raja C Ramachandra, Paramasivam P, Vijayan N
Govt. Arts College, Kumbakonam, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2008 Apr;69(4):1146-9. doi: 10.1016/j.saa.2007.06.014. Epub 2007 Jun 22.
A novel organic non-linear optical organic single crystal of 4-phenylpyridinium hydrogen squarate (4PHS) has been synthesized and successfully grown from aqueous solutions by slow evaporation solution growth method. In the present investigation the title compound has been synthesized by taking equimolar quantity of 4-phenylpyridine and squaric acid and mixed thoroughly using double distilled water as the solvent. The prepared concentrated solution was placed in an undisturbed condition, and then the solution was periodically inspected. The good quality single crystals have been harvested in a time span of 3 weeks. Then the grown crystal was characterized as single crystal XRD, differential thermal analysis, thermogravimetric analysis, FTIR, UV-vis-NIR, SHG, (1)H NMR and (13)C NMR analyses, respectively. The observed results from the characterization analyses show its suitability for NLO applications when compared with some of the existing organic crystals. The relative second harmonic generation of this grown crystal was found to be five times higher than that of KDP crystal. The UV cut-off wavelength and decomposition temperature of this grown crystal were also comparatively better. (1)H NMR and (13)C NMR spectroscopic studies were employed to elucidate the structure of the grown specimen.
一种新型的有机非线性光学有机单晶4-苯基吡啶氢方酸盐（4PHS）已通过缓慢蒸发溶液生长法从水溶液中合成并成功生长出来。在本研究中，通过取等摩尔量的4-苯基吡啶和方酸，并以双蒸水为溶剂充分混合来合成标题化合物。将制备好的浓缩溶液置于不受干扰的条件下，然后定期检查溶液。在3周的时间内收获了高质量的单晶。然后分别对生长的晶体进行了单晶XRD、差示热分析、热重分析、FTIR、紫外-可见-近红外、SHG、（1）H NMR和（13）C NMR分析。表征分析的观察结果表明，与一些现有的有机晶体相比，它适用于非线性光学应用。发现这种生长晶体的相对二次谐波产生比KDP晶体高五倍。这种生长晶体的紫外截止波长和分解温度也相对较好。采用（1）H NMR和（13）C NMR光谱研究来阐明生长样品的结构。
