中文摘要：

合成了三个系列,共二十四个有两种不同软链的对称和非对称苯并菲盘状液晶化合物,C18H6（OR）3-（OCH2COOEt）3,C18H6（OR）3（OCH2COOBu）3,C18H6（OR）3（OCH2CONHBu）3,其中R=C5H11,C6H13,C7H15,C8H17.化合物通过柱层析纯化,结构通过1H NMR,IR,元素分析等确证.化合物热稳定性通过TGA测定,并显示出较高的热稳定性.通过偏光显微镜和差视扫描量热法对这些化合物的热致液晶性进行了研究.结果显示：对于苯并菲液晶化合物C18H6（OR）3（OCH2COOEt）3,非对称性化合物较之对称异构体化合物有更低的熔点和更高的清亮点,因而非对称性化合物有更宽的介晶温度范围.对于分子中含有酰胺基的苯并菲液晶化合物C18H6（OR）3（OCH2CONHBu）3,对称化合物有比非对称异构体更高的清亮点和更有序的六方柱状介晶相,且其与具有同样软链长度的分子中不含酰胺基的化合物系列C18H6（OR）3（OCH2COOBu）3相比较,由于柱内分子间氢键的形成,不仅有更高的熔点和清亮点,而且有更丰富的柱状介晶相.

英文摘要：

Three series with total number of twenty-four new compounds which are symmetrical and asymmetrical triphenylene discotic liquid crystals with two different kinds of peripheral chains, C18H6（OR）3（OCH2COOEt）3, C18H6（OR）3（OCH2COOBu）3 and C18H6（OR）3（OCH2CONHBu）3, （R=C5H11, C6H13, C7H15, C8H17） were synthesized. The purification was carried out with column chromatography and structure characterization of these compounds was carried out with ^1H NMR, IR and elementary analysis. The thermal gravimetry analysis results showed that all these compounds have good thermal stability up to 300℃. Their thermotropic liquid crystal properties were studied with polarizing optical microscopy and differential scanning calorimetry. The results showed that, for compounds C18Hr（OR）3（OCH2COOEt）3, the asymmetrical compounds have lower melting and higher clearing points than that of their corresponding symmetrical compounds, thus asymmetrical compounds have wider mesophase temperature ranges. For the triphenylene derivatives containing amide group with structure of C18H6（OR）3（OCH2CONHBu）3, the symmetrical compounds exhibit higher clearing points and more ordered hexagonal columnar mesophase than their corresponding asymmetrical ones. For comparison of symmetrical and asymmetrical compounds C18H6（OR）3（OCH2CONHBu）3 and C18H6（OR）3（OCH2COOBu）3, the formers have not only higher melting and cleating points but also richer columnar phases than the latter ones due to intermolecular hydrogen bonding.