摘要
用发散法合成周边含36个己氧基偶氮苯介晶基元(M3)端基的新的二代树状碳硅烷液晶(D2),并用元素分析、氢谱、激光质谱、红外光谱、紫外-可见光谱、偏光显微镜,DSC和WAXD法进行表征。D2为向列相,与M3相同.D2液晶态相行为是K90N105I1l3N75K,D2熔点比M3降低26～33℃,D2清亮点比M3降低3～15℃,D2液晶态温区比M3加宽11～30℃。D2和一代树状物D1的相态由介晶基元相态决定。D2熔点比D1降低2～3℃。D2清亮点比D1降低11～21℃,D2液晶态温区比D1减少8～19℃。
The divergent synthesis of a new carbosilane liquid crystalline(LC) dendrimer of the second generation(D2) was described. Thirty-six 4-hexyloxyazobenzene groups (M 3) were used as mesogenic fragments and attached to its periphery. The structure and properties of D2 were characterized by elementary analysis, 1H NMR, MALDI-TOF-MS, IR, UV, polarizing optical micrograph, DSC and WAXD. It is argued that mesophase of nematic type is realized. It is shown that the mesophase type of the dendrimer D2 and D1 essentially depends on the chemical nature of the mesogenic groups and is the same as that of mesogenic unites. The phase behavior of D2 in LC state is K90N105H113N75K. The melting point of D2 decreases 26-33℃ than that of M3, the temperature at its clear point decreases 3-15℃ than that of M3 and its mesophase region is enlarged 11-30 ℃ than that of M3. The melting point of D2 decreases 2-3℃ than that of D1, the temperature at its clear point decreases 11-21℃ than that of D1 and its mesophase region decreases 8-19℃ than that of D1.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2003年第9期1704-1707,共4页
Chemical Journal of Chinese Universities
基金
国家自然科学基金(批准号:29874020
59573029)
中国科学院高分子化学和物理国家重点实验室基金
