Electrochiroptics : Novel Molecular Response System

本研究计画旨在建构一种新颖的分子响应系统，将电化学输入转换成两种光谱输出，即紫外-可见光谱和圆二色光谱。这些材料被命名为“电手性响应系统”，并被认为是有前途的候选人用作手性氧化还原记忆。与广泛研究的以紫外-可见光谱变化作为唯一输出的电致变色材料相比，迄今为止只有少数成功的例子报道。基于我们先前对具有高电化学双稳态的多级氧化还原体系的研究结果，我们设计了几种手性电子供体，它们可以可逆地转化为稳定的双阳离子物种。在相互转化过程中，它们的紫外-可见光谱和圆二色光谱都发生了剧烈的变化。CD信号的高振幅是分子设计中要考虑的中心点之一，我们已经通过位于这些分子中适当位置的两个相同发色团的激子耦合来实现它。我们现在正计划通过制造SAM将这些分子固定在金属表面，这样这些分子就可以用作分子器件。

This research project is intended to construct the novel molecular response systems that transduce the electrochemical input into two kinds of spectral outputs, they are UV-Vis and CD spectra. These materials are named as "electrochiroptical response systems", and considered as promising candidates for use as chiral redox memories. Compared with the extensively studied electrochromic materials giving the UV-Vis spectral change as a sole output, there have been only a few successful examples reported so far. Based on our previous results on the multi-stage redox systems endowed with high electrochemical bistability, we have designed several chiral electron donors that can be reversibly transformed into the stable dicationic species. They exhibited drastic changes in UV-Vis as well as CD spectra during the interconversion. The high amplitude in CD signals is one of the central points to be considered in the molecular design, and we have realized it by exciton coupling of two identical chromophores located at the proper positions in these molecules. We are now planning to fix these molecules on the metal surface by making SAM, so that these molecules can be used as molecular devices.