中文摘要：

2,5-disubstituted thiophene 衍生物的二个系列(系列 1：2,5 二度(p-alkoxyphenylethynyl ) thiophene 和系列 2：2,5 二度[p-(p-alkoxyphenylethynyl )(phenylethynyl )] thiophene ) 被 1H NMR， 13C NMR， HRMS 和元素的分析综合并且描绘。在结构和 mesogenic 和分光镜的性质之间的关系被讨论了。加重 1a1f 的结果表演都展出了二形互变的 nematic mesophase，它被极化的光显微镜学(POM ) 证实，微分 scanningcalorimeter (DSC ) 和可变温度粉末 X 光检查衍射(PXRD ) 。相反，扩大结合的类似物 2a2b 没有液体水晶性质。至于分光镜的性质，合并更多的 phenylethynyl 单位导致转移红的吸收和排放系列，极大地提高的量效率。

英文摘要：

Two series of 2,5-disubstituted thiophene derivatives （series 1： 2,5-bis（p-alkoxyphenylethynyl）thiophene and series 2： 2,5-bis[p-（p-alkoxyphenylethynyl）（phenylethynyl）]thiophene） were synthesized and characterized by ^1H NMR, ^13C NMR, HRMS and elemental analysis. The relationship between the structure and the mesogenic and spectroscopic properties has been discussed. The results show that compounds 1a-1f all exhibited an enantiotropic nematic mesophase, which was confirmed by the polarized optical microscopy （POM）, differential scanning calorimeter （DSC） and variable temperature powder X-ray diffraction （PXRD）. In contrast, the extended conjugated analogues 2a-2b had no liquid crystal properties. As for the spectroscopic properties, incorporating more phenylethynyl units results in red-shifted absorption and emission spectra, greatly enhanced quantum efficiency.