垂直排列液晶盒中反铁电液晶TFMHxPOCBC-D_2偏振红外光谱研究

STUDY OF POLARIZED FT-IR FOR ANTIFERROELECTRIC LIQUID CRYSTAL TFMHxPOCBC-D_2 IN A HOMEOTROPICALLY ALIGNED CELL

本文通过偏振红外吸收光谱研究了铁电与反铁电液晶分子TFMHxPOCBC D2 (4 (trifluoromethylhexy 3 d2 car bonyl) phenyl 4′ octyloxybiphenylcaboxylate)在垂直排列取向液晶盒中CD2 基团绕手征性烷基链转动的受阻行为 .实验结果显示CD2 的偏振红外吸收在Sm C 相不同于Sm C A 相 .建立了一个CD2 转动受阻模型 ,在这一模型的基础上 ,对CD2 的偏振红外吸收进行了模拟计算 ,较好地解释了CD2 红外吸收在铁电和反铁电液晶相下的行为差异 ,得到了CD2 基团绕手征性烷基链转动受阻的结论 .

We have investigated the polarization dependence of FT-IR of the stretching of CD2 in chiral alkyl chain of TFMHx-POCBC-D-2(4-(trifluoromethylhexy-3-d(2) carbonyl) phenyl 4'-octyloxybiphenyl caboxylate) with a homeotropically aligned cell. It is found that the polarization dependence of Sm-C* and that of Sm-C-A* are different. Simulation calculation indicates that the rotation of CD2 around the alkyl chain is hindered.