Redox‐Induced Modulation of Exchange Interaction in a High‐Spin Ground‐State Diradical/Triradical System
Redox‐Induced Modulation of Exchange Interaction in a High‐Spin Ground‐State Diradical/Triradical System
复制标题
高自旋基态二自由基/三自由基系统中交换相互作用的氧化还原诱导调制
DOI：
10.1002/chem.201905465
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Okada Keiji
中科院分区：
文献类型：
--
作者：
Nagata Atsuki;Hiraoka Shinsuke;Suzuki Shuichi;Kozaki Masatoshi;Shiomi Daisuke;Sato Kazunobu;Takui Takeji;Tanaka Rika;Okada Keiji
一种三重基态双自由基分子，双（硝酰基氮氧化物）-取代的二苯基二氢吩嗪（1..），在四重基态下可以转化为单电子氧化物1.+。令人惊讶的是，这些物种，1。和1...+，可以在环境条件下使用，因为它们在需氧条件下甚至在溶液中也相当稳定。温度依赖的磁化率表明，1。和1.+分别处于弱交换作用的三重态（J1/kB=+3.1K）和强交换作用的四重基态（J2/kB=+160K）。 中性和单电子氧化物种之间的相互转化可以通过电化学反应实现。在电化学氧化/还原过程中获得的电子光谱中新出现了近红外区域中显著不同的吸收带。
A triplet ground‐state diradical molecule, bis(nitronyl nitroxide)‐substituted diphenyldihydrophenazine (1..), that can be converted into a one‐electron oxidized species,1…+, in the quartet ground state has been developed. Surprisingly, these species,1..and1…+, can be used under ambient conditions because they are reasonably stable under aerobic conditions, even in solution. The temperature‐dependent magnetic susceptibilities reveal that1..and1…+are in the triplet state, with a weak exchange interaction (J1/kB= +3.1 K) and quartet ground state with a strong exchange interaction (J2/kB= +160 K), respectively. The interconversion between the neutral and one‐electron oxidized species can be realized through electrochemical reactions. Significantly different absorption bands in the near‐IR region newly appeared in the electronic spectra acquired during electrochemical oxidation/reduction.