【摘 要】
：
Symmetrical and asymmetrical triphenylene discotic liquid crystals with two kinds of different peripheral chains, .sym-TP(OC11H23)3(O2CR)3 and asym-TP(OC11H23)3
【机 构】
：
College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610066, China
论文部分内容阅读
Symmetrical and asymmetrical triphenylene discotic liquid crystals with two kinds of different peripheral chains, .sym-TP(OC11H23)3(O2CR)3 and asym-TP(OC11H23)3(O2CR)3, (R = CH2OC2H5,CH2OC3H7, CH2OC4H9, CH2OC5H11, C3H7, C4H9, C5H11, C6H13, C7H15) were synthesized. Their thermotropic liquid crystalline properties were studied by polarizing optical microscopy (POM) and differential scanning calorimetry (DSC). The results showed that the asymmetrical compounds had higher melting and clearing points than that of their corresponding symmetrical compounds. For the same series of compounds, TP(OC11H23)3(O2CR)3, their melting points decrease and clearing points increase gradually with the lengthening of ester chains. Most of the β-oxygen containing esters of triphenylene derivatives, TP (OC11H23)3(O2CR)3, (R = CH2OC2H5, CH2OC3H7, CH2OC4H9, CH2OC5H11), symmetrically or asymmetrically attached on triphenylene cores, have higher melting and clearing points than those of triphenylene derivatives, TPCOC11H23)3(O2CR)3, (R= C4H9, C5HU, C6H13, C7H15), with the same length of peripheral chains. The triphenylene derivatives with longer peripheral chains have shown mesophase at room temperature.
其他文献
每种语言或方言都是当地民众千百年来代代相传下来,耳熟能详的、极其宝贵的语言财富,所以都有其独特的文化内涵。粤方言中俗语和歌曲最能体现粤语独特的文化,粤语俗语多用比
水稻是世界上最重要的粮食作物之一,分布在世界上120多个国家。世界11％的耕地种植水稻,年生产稻谷约6亿吨,稻谷提供了世界全部人口的1/2左右的粮食。水稻品种的多样性、广泛的
本文以重庆梁平双桂堂为契机,以双桂堂山门朝向为研究切入点,从“形”“质”两个向度对双桂堂山门几次变更进行分析,试图阐释双桂堂大山门变更的表层现象和深层内涵,以期解析
3,6-bis(1H-1,2,3,4-tetrazol-5-yl-amino)-1,2,4,5-tetrazine (BTATz) was synthesized by the con-densation of triaminoguanidinium nitrate with 2,4-penta-nedione, fo
Four amphipathic cobalt(Ⅱ),nickel(Ⅱ),copper (Ⅱ),and zinc(Ⅱ) coordination compounds of tetrakis,α,(2,methyl,8,quinolinoxy)phthalocyanine are synthesized usi
石柱础作为宅院艺术中的“根基”,在历史洪流的席卷之下相对完整的遗留下来.立起了一所宅院的根基,恪守了一个家族兴衰的灵性之光.从朱家花园说起,慢慢靠近这风雨百年的老宅,
最近,在上海新民晚报上看到一则新闻(后被一些文摘报刊转载):《国外流传一则耸人听闻消息苏联医生替外星人接生》。消息说,1984年9月,有一
Recently, a news story was see
5-HT3 receptor antagonists, such as Ondanse-tron, are used for anti-emesis after chemotherapy, radio-therapy and operations. Some Ondansetron analogs possessing
The synthesis of high-nitrogen energetic material 3,3’-azobis (6-amino-l,2,4,5-tetrazine) (DAAT) from 3,6-bis (3,5-dimethylpyrazol-1-yl)-1,2,4,5-tetrazine by a
Manganese dioxides with various morphologies were prepared using a common hydrothermal method without any templates or additives.The evolution of the morphology