Absorption, Photoluminescence, and Polarized Raman Spectra of a Fourfold Alkoxy-Substituted Phthalocyanine Liquid Crystal

Absorption, photoluminescence, and Raman scattering measurements have been performed on a fourfold alkoxy-substituted phthalocyanine in solution and in the discotic liquid crystal phase. As already known for this class of compounds, the features of the electronic spectra in the condensed state are determined by the spatial closeness and arrangement of the π systems of the phthalocyanine cores, with the occurrence of collectively excited states and excimer-like emission. Quantitative information about the alignment of the molecules which compose the liquid crystal phase has been obtained from the analysis of polarized Raman spectra of homeotropically aligned samples.本研究针对溶液及盘状液晶相(discotic liquid crystal phase)中的四烷氧基取代酞菁(phthalocyanine)开展了吸收、光致发光(photoluminescence)与拉曼散射(Raman scattering)测试。正如该类化合物的已有研究共识，凝聚态下的电子光谱特征由酞菁母核π体系的空间邻近性与排布方式决定，同时存在集体激发态与类激基缔合物发射。通过对垂直取向(homeotropically aligned)样品的偏振拉曼光谱进行分析，我们获取了构成该液晶相的分子取向的定量信息。