Development of New Organic Materials with Photochromic or Electro-Chromic Function

本研究的目的是利用新型的PI共轭化合物开发多色有机电致变色体系和高灵敏光色体系。新合成的四(4-羟基苯基)硫代噻吩烯、1，3-二硫醇-放射烯和树烯与其对应的氧化物种形成了可逆的氧化还原体系，并观察到明显的三色变化。由于其在长波区的固有光谱敏感性以及对光降解的抵抗力，因此被选为光致变色分子的基本分子骨架。我们使用了空间应变，它迫使芳环在振动模式下弯曲，可用于光化学形成价异构体，如杜瓦和瓦伦异构体。在此基础上合成了1，2，3-三叔丁基安息香酚。与母体分子的电子光谱相比，1，2，3-三叔丁基蒽醌的光谱具有最长的吸收带，最大的消光系数为3500。该带的基色位移也很显著，其吸收截止可达550 nm左右。辐照后，该分子发生可逆价异构化反应，形成相应的半杜瓦型蒽醌衍生物。为了提高光谱灵敏度，对萘并苯二酮进行了取代修饰。1，2，3-三叔丁基萘并苯二酮得到相应的半杜瓦异构体，而7，8，9-三叔丁基体系得到戊烯异构体。这两种光化学异构化反应都是可逆的和定量的。这些新的光致变色系统将具有实际应用价值。

This research has been carried out with aim of developing both multi-color organic electrochromic systems and highly sensitive photochromic systems by use of novel pi conjugated compounds. The newly prepared tetrakis(4-hydroxyphenyl)thienothiophene and 1,3-dithiole- radialenes and dendralenes constructed reversible redox systems with their corresponding oxidized species, and vivid three color change was observed. Anthraquinone was chosen as a fundamental molecular skeleton for photochromic molecule, because of its intrinsic spectral sensitivity at long wavelength region as well as its resistibility toward photo-degradation. We employed steric strain, which forces bending of the aromatic ring in a vibrational mode operative for photochemical formation of valence isomers such as Dewar and valene isomers. Thus, 1,2,3-tri-t-butyl anthraquinone was synthesized. Comparing to the electronic spectrum of the parent molecule, the spectrum of 1,2,3-tri-t-butylanthraquinone was characteristic having a longest absorption band with a large extinction coefficient of 3500. The bathochromic shift of the band is also notable, and its absorption cut-off reaches to ca. 550 nm. Upon irradiation, the molecule undergoes reversible valence isomerizations between the corresponding hemi-Dewar anthraquinone derivative. The substitutional modification was employed in naphthacenequinone in order to improve spectitral sensitivity. 1,2,3-tri-t-butylnaphthacenequinone gave the corresponding hemi-Dewar isomer, whereas the 7,8,9-tri-t-butyl system gave the valene isomer. Both the photochemical isomerizations was reversible and quantitative. These new photochromic systems would be practically of practical use.