Near‐Infrared Electrochromic Behavior of Dibenzothiepin Derivatives Attached with Two Michler's Hydrol Blue Units
Near‐Infrared Electrochromic Behavior of Dibenzothiepin Derivatives Attached with Two Michler's Hydrol Blue Units
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附有两个米希勒氢蓝单元的二苯并硫杂平衍生物的近红外电致变色行为
DOI：
10.1002/chem.202202457
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Suzuki Takanori
中科院分区：
文献类型：
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作者：
Ishigaki Yusuke;Takata Masaki;Shimajiri Takuya;Wu Luyan;Zeng Wenhui;Ye Deju;Suzuki Takanori
合成了10，11-双[双（4-二甲氨基苯基）亚甲基]二苯并[bf]硫杂卓（1）和-氧杂卓（2），它们是稳定的黄色晶体化合物，是给电子的六芳基丁二烯的环状类似物。在双电子氧化后，它们可逆地转化为具有近红外（NIR）吸收的标题二价阳离子（12+和22+），其也被分离为稳定的盐。这些氧化还原对可以作为新的进入较少开发的有机近红外电致变色系统，并且由于中性和双阳离子状态之间的剧烈几何变化，1/12+和2/22+实现了氧化还原峰的分离（电化学双稳态），如一系列X射线分析所揭示的。由于12+和22+中的二苯并硫杂卓和-氧杂卓单元的非芳族性质，硫杂卓-S，S-二氧化物类似物（3/32+）表现出非常相似的动态氧化还原行为，而硫杂卓-S-氧化物衍生物（4/42+）由于电子转移时几何结构的较小变化而不表现出双稳态，表明中心七元环中桥接原子的细微变化可以改变氧化还原性质。
10,11‐Bis[bis(4‐dimethylaminophenyl)methylene]dibenzo[bf]thiepin (1) and ‐oxepin (2) were prepared as stable yellow crystalline compounds, which are the cyclic analogues of electron‐donating hexaarylbutadienes. Upon two‐electron oxidation, they are reversibly transformed into the title dications (12+and22+) exhibiting near‐infrared (NIR) absorptions, which were also isolated as stable salts. These redox pairs can serve as new entries into less well‐explored organic NIR‐electrochromic systems, and the separation of redox peaks (electrochemical bistability) was attained for1/12+and2/22+, thanks to drastic geometrical changes between neutral and dicationic states, as revealed by a series of X‐ray analyses. Thiepin‐S,S‐dioxide analogue (3/32+) exhibits quite similar dynamic redox behavior due to nonaromatic nature of the dibenzothiepin and ‐oxepin unit in12+and22+, whereas the thiepin‐S‐oxide derivative (4/42+) does not exhibit bistability due to the smaller change in geometry upon electron transfer, showing that a subtle change of a bridging atom in the central seven‐membered ring can modify the redox properties.