Self-Organization of Bilayr-Forming Crystals

本研究项目的目的是了解两亲分子在溶液中自发组织的基本聚集原理。为此，通过烷基链长度m和n的系统变化，研究了含偶氮苯两亲体C_nAzoC_mN^+Br^-的化学结构与双层结构之间的关系。(1)对于m-n<或等于>2的化合物，偶氮苯发色团平行排列并排，双分子层两侧的两亲分子相互交错。这种堆积方式被称为“h -骨料”结构。特别是对m-n=2的化合物进行了结晶，并对其结构进行了精确分析。m-n<等于或大于bbb2的化合物的铸膜虽然呈现h聚集结构，但其稳定性随着m-n与2的差值的增大而降低。(2)在化合物与m = 5, azob ... 更多enzene生色团头到尾的方式排列和两亲物分子倾斜约30゚bilayr表面。这种包装方式被称为“j -聚集体”结构。这类化合物易于结晶，每个样品都经过分析以获得精确的双层结构。(3)不同m和n的化合物在高温下均发生晶-晶转变，高温下的结构与j -聚集结构相似，不依赖于原来的聚集结构。(4)从上述实验结果可以得出以下结论：疏水部分和亲水部分之间的截面平衡是双层结构形成的重要驱动力。通过改变尾部(n)和间隔(m)部分的碳原子数来控制双层结构。此外，在h聚集态的情况下，微小的结构差异可以通过奇数或偶数Less来控制

The purpose of this research project is to understand the fundamental aggregation principle when amphiphile molecules organize spontaneously in solution by themselves. To do this, the relationship between chemical structures and bilayr structures of azobenzene-containing amphiphiles C_nAzoC_mN^+Br^- were thoroughly investigated by the systematic change of alkyl chain lengths, m and n.Following results were obtained. (1) For the compounds with m-n<greater than or equal>2, azobenzene chromophores are parallely arranged in a side by side fashion and amphiphile molecules from both sides of a bilayr interdigitate each other. This packing mode was called "H-aggregate" structure. Especially, the compounds with m-n=2 were crystallized and their structures were analyzed precisely. Although cast films of compounds with m-n<greater than or equal>2 showed H-aggregation structure, their stability decreased with the increase of the difference (m-n) from 2. (2) In the case of compounds with m=5, azob … More enzene chromophores are arranged in a head to tail fashion and amphiphile molecules tilt by about 30ﾟ to the bilayr surface. This packing mode was called "J-aggregate" structure. This group of compounds was easy to crystallize and every specimen was analyzed to get precise bilayr structures. (3) Every compound with different m and n showed a crystal-crystal transition at elevated temperature and their structures at higher temperature seemed to be similar to the J-aggregation structure, independent on their original aggregation structures. (4) From the above experimental results the following conclusions were obtained. The cross-section balance between the hydrophobic part and the hydrophilic part is most important as a driving force in the formation of bilayr structures. The bilayr structure was controlled by changing the number of carbon atoms in the tail (n) and the spacer (m) part. Moreover, in the case of H-aggregation state, small structural differences could be controlled by the odd or even Less