摘要
研究了树外围含36个硝基偶氮苯端基新型二代碳硅烷光致变色液晶树枝状大分子(G2)在溶液中的最大吸收波长,摩尔消光系数,反-顺光异构化反应速率常数,热回复异构化反应速率常数,光化学回复异构化反应平衡常数及速率常数.G2的光致变色反应速率常数的数量级为10-1s-1,而含偶氮端基侧链聚硅氧烷的光致变色反应速率常数的数量级为10-8s-1,因此,液晶树枝状大分子的光响应速率比后者快107倍.G2的光化学回复异构化反应平衡常数kt/kc为1.77～1.97,有作为光控开关材料的应用前景.
The molar extinction coefficient, maximum absorption wavelength, reaction rate constants of trans/cis photochemical isomerization, thermal back-isomerization and photochemical back-isomerization and equilibrium constant of photochemical back-isomerization reaction of a novel photochromic liquid crystalline dendrimer （G2） of the second generation containing nitroazophenyl groups on its periphery in solution were described. Photochromic reaction rate constant of G2 in CHC13 and THF was 10^-1s^-1, but that of photochromic side-chain polysiloxanes containing azophenyl moieties was 10^-8 s^-1, thus the photoresponsive rate of the liquid crystalline dendrimer G2 is 107 times larger than that of the latter. The equilibrium constant kt/kc of photochemical back-isomerization reaction of G2 are 1.77- 1.97 approaching to 1, and thus it is applicable to photoswitch materials.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2006年第15期1593-1600,共8页
Acta Chimica Sinica
基金
国家自然科学基金(Nos.29874020
59575029)
山东省自然科学基金
中国科学院高分子物理重点实验室资助项目.
关键词
光致变色液晶树枝状大分子
光异构化
光回复异构化
热回复异构化
光控开关材料
光电信息存贮材料
photochromic liquid crystalline dendrimer
photoisomerization
photo back-isomerization
thermal back-isomerization
photoswitch material
photoelectrical informational storage material
