Photochromism of 1,2-bis(2,5-dimethyl-3-thienyl)perfluorocyclopentene in a single crystalline phase
Photochromism of 1,2-bis(2,5-dimethyl-3-thienyl)perfluorocyclopentene in a single crystalline phase
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DOI：
10.1021/ja983717j
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发表时间：
1999-03-24
影响因子：
15
通讯作者：
Irie, M
中科院分区：
文献类型：
--
作者：
Kobatake, S;Yamada, T;Irie, M
发现1,3-双(2,5-二甲基-3-噻吩基)全氟环戊烯(la)在单晶相中发生光致变色。用紫外线照射时，无色晶体变成红色，并保持晶体形状。红色归因于闭环形式Ib，红色通过可见光（λ> 450 nm）照射而褪色。通过旋转晶体样品，在偏振光下观察到的红色强度发生了显着变化，有序参数高达0.84。高阶参数证实分子在晶格中发生光致变色。由535nln处的吸收各向异性估算出的Ib的电子跃迁矩的方向与通过X射线晶体学分析确定的晶体中填充的la的长轴一致。通过比较la和Ib的结构来估计环化反应期间晶体中分子的每个原子的运动，这两者都是通过X射线分析确定的。
1,3-Bis(2,5-dimethyl-3-thienyl)perfluorocyclopentene (la) was found to undergo photochromism in a single crystalline phase. Upon irradiation with ultraviolet light the colorless crystal turned red with keeping the crystal shape. The red color is due to the closed-ring form Ib, The red color was bleached by irradiation with visible light (lambda > 450 nm). The intensity of the red color observed under polarized light dramatically changed by rotating the crystal sample, and the order parameter was as high as 0.84. The high order parameter confirmed that the molecules undergo photochromism in the crystalline lattice. The direction of the electronic transition moment of Ib estimated from the absorption anisotropy at 535 nln agreed with the long axis of la packed in the crystal, which was determined by X-ray crystallographic analysis. The movement of each atom of the molecule in the crystal during the cyclization reaction was estimated by comparing the structures of la and Ib, both of which were determined by X-ray analysis.