Selenium-Selenium Bond Cleavage of Diaryl Diselenide Radical Anions During Pulse Radiolysis
Selenium-Selenium Bond Cleavage of Diaryl Diselenide Radical Anions During Pulse Radiolysis
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脉冲辐射分解过程中二芳基二硒化物自由基阴离子的硒-硒键断裂
DOI：
10.1002/cplu.201402376
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发表时间：
2015
期刊：
影响因子：
3.4
通讯作者：
Tetsuro
中科院分区：
文献类型：
--
作者：
S. Tojo;M. Fujitsuka; A. Ouchi;T. Majima;Tetsuro
用吸收光谱法研究了2-甲基四氢呋喃中二芳基二硒阴离子自由基（ArSeSeAr. -）的硒-硒σ键（Se <$Se）断裂.一个二-α-萘基二硒阴离子自由基（αNpSeSeαNp.−）在77 K时在440 nm处有一个吸收带，其中一个未成对电子位于两个Se原子之间的Se <$Se σ* 轨道上，并有一个延长的Se <$Se键。 随着温度的升高，在440 nm处的吸收带移动到540 nm，从而表明未成对电子在两个萘环和Se → Se键上离域。 在αNpSeSeαNp. -的脉冲辐解过程中，观察到540 nm处的吸收带消失，420、620和690 nm处的吸收带形成，归属于α-萘基硒基自由基，从而表明在αNpSeSeαNp. -中发生了Se Se键断裂。 讨论了ArSeSeAr-中Se → Se键断裂与未成对电子离域的关系。
A seleniumselenium σ‐bond (SeSe) cleavage of a diaryl diselenide radical anion (ArSeSeAr.−) was investigated by absorption measurements during the γ radiolysis and pulse radiolysis in 2‐methyltetrahydrofuran. A di‐α‐naphthyl diselenide radical anion (αNpSeSeαNp.−) in which an unpaired electron is localized in the SeSe σ* orbital between both Se atoms with an elongated SeSe bond showed an absorption band at 440 nm at 77 K. Upon increasing temperature, the absorption band at 440 nm shifted to 540 nm, thus suggesting that an unpaired electron is delocalized over two naphthalene rings and the SeSe bond. The disappearance of the absorption band at 540 nm and formation of absorption bands at 420, 620, and 690 nm assigned to the α‐naphthylselenyl radical were observed during the pulse radiolysis ofαNpSeSeαNp, thus indicating that the SeSe bond cleavage occurred inαNpSeSeαNp.−. The relationship between the SeSe bond cleavage and delocalization of the unpaired electron in ArSeSeAr.−is discussed.