Modification of the nanoscale structure of the J-aggregate of a sulfonate-substituted amphiphilic carbocyanine dye through incorporation of surface-active additives
Modification of the nanoscale structure of the J-aggregate of a sulfonate-substituted amphiphilic carbocyanine dye through incorporation of surface-active additives
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DOI：
10.1021/jp065826n
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发表时间：
2007-02-22
影响因子：
3.3
通讯作者：
Boettcher, Christoph
中科院分区：
文献类型：
--
作者：
von Berlepsch, Hans;Kirstein, Stefan;Boettcher, Christoph
两亲性染料3,3'-双(2-磺丙基)-5,5',6,6'-四氯-1,1'-二辛基苯甲酰亚胺羰花青(C8S3)在水溶液中自聚集形成管状J-聚集体，直径为17.0 +/- 0.5 nm，壁厚约为4 nm，长度为 超过数百纳米。吸收光谱显示了管状 J 聚集体的典型特征，具有几个尖锐的红移吸收带。使用冷冻透射电子显微镜 (cryo-TEM) 和光谱研究进行的形态学研究表明，管状形态具有高度稳定性，但在储存几周后，聚集体有组装成绳状束的趋势。研究发现，含有添加剂（例如醇或表面活性剂）的溶液中的聚集会导致新型聚集体的形成。当溶液含有超过 10 wt% MeOH 时，会观察到直径为 13.0 +/- 0.5 nm 的第二种类型的管状聚集体。在数天的时间尺度上，这些管状聚集体转变为以新吸收光谱为特征的带状结构，并在几周后转变为直径高达 500 nm 的巨型管。
The amphiphilic dye 3,3'-bis(2-sulfopropyl)-5,5',6,6'-tetrachloro-1,1'-dioctylbenzimidacarbocyanine (C8S3) self-aggregates in aqueous solution to form tubular J-aggregates with a diameter of 17.0 +/- 0.5 nm, a wall thickness of similar to 4 nm, and a length exceeding several hundred nanometers. The absorption spectrum shows the typical features expected for tubular J-aggregates with several sharp and red-shifted absorption bands. Morphological investigations using cryo-transmission electron microscopy (cryo-TEM) and spectroscopic investigations reveal a high stability of the tubular morphology but a tendency of the aggregates to assemble into ropelike bundles after several weeks of storage. It is found that aggregation in solutions containing additives such as alcohols or surfactants results in the formation of new types of aggregates. A second type of tubular aggregate with a diameter of 13.0 +/- 0.5 nm is observed when the solutions contain more than 10 wt % MeOH. On the time scale of days these tubular aggregates transform into ribbonlike structures characterized by a new absorption spectrum, and they convert after several weeks into giant tubes with diameters of up to 500 nm.