Development of new multi-color electrochromic system by use of redox-active pi conjugated compounds

利用氧化还原活性π共轭化合物开发新型多色电致变色系统

基本信息

批准号：
63550646
负责人：
SUGIMOTO Toyonari
金额：
$ 1.02万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1989
项目状态：
已结题

项目摘要

Organic compounds with multi-color change are of current interest from development of new types of display systems. This research project has been carried out with aim of developing such multi-color organic electrochromic systems by use of the following redox-active pi conjugated compounds: (1) tetrakis(2,6-di-tert-butyl-4-hydroxyphenyl)- thieno[3,2-b]thiophene (1), (2) 1,3-dithiole-[n]radialenes (n=3, 4, 5, 6) (2), and (3) 1,3-dithiole-[n]dendralenes (n=3, 4) (3). As for 1 a reversible redox system was constructed with the corresponding two- and four-electron oxidized compounds, the mono- quinone (1') and diquinone (1''). Between the three components a large color change was observed: 1 (pale yellow), 1' (blue), and 1'' (brown red). It was very surprising that 1' and 1'' have absorption maxima at fairly long wavelength region, in spite of their not so large pi conjugation. As a result of some investigations, it was suggested that the excited state (biradical structure) might be located at comparatively low energy level and the transition energy from HOMO to LUMO might become very smaller. The indirect evidence to this suggestion was obtained from the detailed esr measurement of 1' and 1'', in which certainly the biradical involvement was recognized. Also, 2 and 3 exhibited electrochromism between their radical cations and dications. In particular, a comparatively large three color change was observed between 3 (yellow), and the radical cation (dark blue) and dication (green).

具有多色变化的有机化合物目前在新型显示系统的开发中引起了人们的兴趣。本研究项目的目的是通过使用以下氧化还原活性π共轭化合物开发这种多色有机电致变色系统：（1）四（2,6-二叔丁基-4-羟基苯基）-噻吩并[3,2-b]噻吩 (1)、(2) 1,3-二硫醇-[n]辐射烯 (n=3、4、5、6) (2) 和 (3) 1,3-二硫醇-[n]树枝烯 (n=3, 4) (3)。对于1，用相应的二电子和四电子氧化化合物，单醌(1')和二醌(1'')构建了可逆氧化还原系统。在这三个组件之间观察到较大的颜色变化：1（浅黄色）、1'（蓝色）和 1''（棕红色）。非常令人惊讶的是，尽管 1' 和 1'' 的 pi 共轭性不是那么大，但它们在相当长的波长区域具有吸收最大值。一些研究的结果表明，激发态（双自由基结构）可能位于相对较低的能级，并且从 HOMO 到 LUMO 的跃迁能量可能会变得非常小。这一建议的间接证据是从 1' 和 1'' 的详细 ESR 测量中获得的，其中肯定存在双自由基参与。此外，2和3在其自由基阳离子和双阳离子之间表现出电致变色。特别是，在3（黄色）、自由基阳离子（深蓝色）和阳离子（绿色）之间观察到相对较大的三色变化。