Liquid crystalline and nonlinear optical properties of bent-shaped compounds derived from 3,4′-biphenylene
作者:Inmaculada C. Pintre、Nélida Gimeno、José Luís Serrano、M. Blanca Ros、Ibon Alonso、César L. Folcia、Josu Ortega、Jesús Etxebarria
DOI:10.1039/b700636e
日期:——
The synthesis of different bent-core molecules derived from 3,4â²-biphenylene bearing azo, azoxy, imine or ester linkages in their lateral structures is reported. Structureâactivity relationships for their liquid crystalline behaviour are discussed. SmCP, USmCP and Colob mesophases are found depending on the type and number of these connecting units. The sequence ester â azoxy > imine > azo can be proposed for the mesophase range, with significant differences observed in terms of mesopahase stabilization. SHG studies on these compounds give nonlinear coefficients in the range of 1â8 pm Vâ1. The molecular origin for these values is analyzed semi-quantitatively. It was concluded that the SHG performance of bent-core mesogens in general can still be increased substantially. An approach to improve the properties of these materials is briefly outlined.
报告中介绍了由 3,4â²-联苯衍生出的不同弯核分子的合成过程,这些分子的横向结构中含有偶氮、偶氮氧、亚胺或酯连接。报告还讨论了其液晶行为的结构与活性关系。根据这些连接单元的类型和数量,发现了 SmCP、USmCP 和 Colob 介相。介相范围的顺序为酯 - 偶氮 > 亚胺 > 偶氮,在介相稳定性方面存在显著差异。对这些化合物进行的 SHG 研究得出了 1â8 pm Vâ1 范围内的非线性系数。对这些数值的分子来源进行了半定量分析。得出的结论是,一般来说,弯曲核介质的 SHG 性能仍可大幅提高。简要概述了改善这些材料性能的方法。