Aggregation behavior and chromonic liquid crystal phase of a dye derived from naphthalenecarboxylic acid.
Aggregation behavior and chromonic liquid crystal phase of a dye derived from naphthalenecarboxylic acid.
复制标题
萘甲酸染料的聚集行为和发色液晶相。
DOI：
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发表时间：
2008
影响因子：
3.3
通讯作者：
P. Collings
中科院分区：
文献类型：
--
作者：
M. Tomasik;P. Collings
Polarizing microscopy, X-ray scattering, and absorption spectroscopy are used to investigate the aggregation process and chromonic liquid crystal of the anionic compound Bordeaux dye, a product of the sulfonation of the dibenzimidazole derivative of naphthalenetetracarboxylic acid. Polarizing microscopy reveals that the liquid crystal phase forms at room temperature when the concentration is only about 6 wt%, a value lower than what is found in many aggregating systems. The X-ray results indicate that the aggregation is via columns, with a cross-sectional area about 2.5 times larger than the individual molecule. Absorption spectroscopy shows a significant change in the absorption spectrum due to aggregation, which is nicely explained by a simple theory of isodesmic aggregation and excitonic coupling between the molecules in an aggregate. The "stacking free energy change" for a molecule in an aggregate relative to a molecule in solution is estimated to be about 9 kBT, a larger value than that found in the one other system where it has been estimated.
