Key Laboratory of Colloid and Interface Chemistry, Shandong University, Ministry of Education , Jinan 250100, China.
Key Laboratory of Coal Science and Technology of Ministry of Education and Shanxi Province, Taiyuan University of Technology , Taiyuan 030024, China.
Langmuir. 2016 Aug 16;32(32):8163-70. doi: 10.1021/acs.langmuir.6b01937. Epub 2016 Aug 5.
A novel photoresponsive surface active ionic liquid (SAIL) 1-(4-methyl azobenzene)-3-tetradecylimidazolium bromide ([C14mimAzo]Br) with azobenzene located in the headgroup was designed. Reversible vesicle formation and rupture can be finely controlled by photostimuli without any additives in the aqueous solution of the single-tailed ionic liquid. The photoisomerization of the azobenzene derivative was investigated by (1)H NMR and UV-vis spectroscopy. Density functional theory (DFT) calculations further demonstrate that trans-[C14mimAzo]Br has less negative interaction energy, which is beneficial to aggregate formation in water. The incorporation of trans-azobenzene group increases the hydrophobicity of the headgroup and reduces the electrostatic repulsion by delocalization of charge, which are beneficial to the formation of vesicles. However, the bend of cis-azobenzene makes the cis-isomers have no ability to accumulate tightly, which induces the rupture of vesicles. Our work paves a convenient way to achieve controlled topologies and self-assembly of single SAIL.
设计了一种具有偶氮苯位于头基的新型光响应表面活性离子液体（SAIL）1-（4-甲基偶氮苯）-3-十四烷基咪唑溴盐（[C14mimAzo]Br）。在单尾离子液体的水溶液中，无需添加任何添加剂，即可通过光刺激精细控制可逆囊泡的形成和破裂。通过（1）H NMR 和紫外可见光谱研究了偶氮苯衍生物的光异构化。密度泛函理论（DFT）计算进一步表明，反式-[C14mimAzo]Br 具有更小的负相互作用能，有利于在水中聚集形成。反式偶氮苯基团的引入增加了头基的疏水性，并通过电荷离域减少了静电排斥，有利于囊泡的形成。然而，顺式偶氮苯的弯曲使得顺式异构体没有紧密堆积的能力，导致囊泡破裂。我们的工作为实现单 SAIL 的可控拓扑和自组装铺平了便捷的道路。
