Crystal engineering of photochromic diarylethene single crystals.
Crystal engineering of photochromic diarylethene single crystals.
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DOI：
10.1002/tcr.10078
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发表时间：
2004
期刊：
影响因子：
6.6
通讯作者：
M. Morimoto;S. Kobatake;M. Irie
中科院分区：
文献类型：
--
作者：
M. Morimoto;S. Kobatake;M. Irie
利用芳香-芳香非共价相互作用作为分子间的定向力，通过晶体工程方法控制二芳基乙烯单晶的光致变色性能。含两个五氟苯基的二芳基乙烯衍生物1，2-双（2-甲基-5-五氟苯基-3-噻吩基）全氟环戊烯（1a）通过芳基-全氟芳基相互作用与苯（Bz）和萘（Np）形成化学计量的共晶。1a的五氟苯基基团与芳香族分子之间的面对面π堆积相互作用分别导致1a/Bz和1a/Np共晶体中的2：1和1：1化学计量组成。二芳基乙烯在1a的同晶和共晶1a/Bz和1a/Np中发生了热稳定的光致变色反应。光生的闭环异构体的吸收光谱的变化取决于在晶体中的二芳基乙烯分子的构象包装。二芳基乙烯1a还与不同种类的二芳基乙烯、1，2-双（2-乙基-5-苯基-3-噻吩基）全氟环戊烯（2a）和1，2-双[2-甲基-5-（1-萘基）-3-噻吩基]全氟环戊烯（3a）形成1：1化学计量比的共晶体。共晶1a/2a和1a/3a均表现出光致变色性。尽管1a、2a和3a在其均晶中经历了有效的光环化反应，但在共晶中观察到2a或3a的高度选择性光环化反应。通过HPLC和X射线晶体学证实了选择性反应。从1a到2a和从1a到3a的激发能量转移被认为是发生的，并引起选择性反应。
Photochromic performance of diarylethene single crystals was controlled by crystal engineering using non-covalent aromatic-aromatic interactions as the directional intermolecular force. A diarylethene derivative with two pentafluorophenyl groups, 1,2-bis(2-methyl-5-pentafluorophenyl-3-thienyl)perfluorocyclopentene (1a), formed stoichiometric co-crystals with benzene (Bz) and naphthalene (Np) by aryl-perfluoroaryl interactions. Face-to-face pi-stacking interactions between the pentafluorophenyl groups of 1a and the aromatic molecules are responsible for 2:1 and 1:1 stoichiometric compositions in 1a/Bz and 1a/Np co-crystals, respectively. The diarylethene underwent thermally stable and photoreversible photochromic reactions in a homo-crystal of 1a and co-crystals 1a/Bz and 1a/Np. The absorption spectra of the photogenerated closed-ring isomers varied depending on the conformation of the diarylethene molecules packed in the crystals. The diarylethene 1a also formed 1:1 stoichiometric co-crystals with different kinds of diarylethenes, 1,2-bis(2-ethyl-5-phenyl-3-thienyl)perfluorocyclopentene (2a) and 1,2-bis[2-methyl-5-(1-naphthyl)-3-thienyl]perfluorocyclopentene (3a). Both co-crystals 1a/2a and 1a/3a showed photochromism. Although 1a, 2a, and 3a underwent efficient photocyclization reactions in their homo-crystals, highly selective photocyclization reactions of 2a or 3a were observed in the co-crystals. The selective reactions were confirmed by HPLC and X-ray crystallography. Excited energy transfers from 1a to 2a and from 1a to 3a are considered to occur and cause the selective reactions.