Odd-even effects in azobenzene-urea amphiphile assemblies
Odd-even effects in azobenzene-urea amphiphile assemblies
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DOI：
10.1021/la035056w
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发表时间：
2003-10-28
期刊：
影响因子：
3.9
通讯作者：
Seki, T
中科院分区：
文献类型：
--
作者：
Kobayashi, T;Seki, T
合成了具有脲头基的偶氮苯 (Az) 衍生物 n-{4-[(4-己基苯基)偶氮]苯氧基}烷基脲（6Azn-脲，n = 3、4、5、6 和 7）。通过表面压力面积等温线和压缩性测量、紫外可见和红外吸收光谱以及X射线衍射测量，研究了一系列6Azn-脲化合物的单层和多层结构的特性。在朗缪尔单层在水面上的铺展行为和流变特性、从水表面到固体基质的转移行为、沉积单层和多层中分子倾斜和AZ聚集的堆积状态以及多层中氢键的性质中，观察到各种类型的奇偶效应。 6Azn-脲单层中的碳宇称性质应该是由于通过分子间分叉氢键牢固固定在末端脲头基上，这类似于共价连接到固体基底上的自组装单层的情况。
Azobenzene (Az) derivatives with a urea headgroup, n-{4-[(4-hexylphenyl)azo]phenoxy}alkylurea (6Azn-urea, n = 3, 4, 5, 6, and 7), were synthesized. The characteristics of mono- and multilayers of a series of 6Azn-urea compounds were investigated by means of surface pressure-area isotherm and compressibility measurements, UV-visible and infrared absorption spectroscopy, and X-ray diffraction measurements. Various types of odd-even effects were observed in the spreading behavior and rheological properties in the Langmuir monolayer on the water surface, in the transfer behavior from the water surface to a solid substrate, in the packing state in terms of molecular tilt and Az aggregation in the deposited mono- and multilayers, and in the nature of hydrogen bonding in the multilayers. The carbon parity nature in the 6Azn-urea monolayer should result from the firm fixation at the terminal urea headgroup via intermolecular bifurcated hydrogen bonding, which resembles the situation of self-assembled monolayers attached covalently onto a solid substrate.