Oxidation of Triplet C60 by Hydrogen-Bonded Chloranil: Efficient Formation, Spectrum and Charge-Shift Reactions of C60+• Cation Radical
Oxidation of Triplet C60 by Hydrogen-Bonded Chloranil: Efficient Formation, Spectrum and Charge-Shift Reactions of C60+• Cation Radical
复制标题
氢键四氯苯醌对三线态 C60 的氧化：C60+• 阳离子自由基的有效形成、谱图和电荷转移反应
DOI：
10.1021/jp012778s
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发表时间：
2001
影响因子：
2.9
通讯作者：
H. Linschitz
中科院分区：
文献类型：
--
作者：
L. Biczók;H. Linschitz
三氟乙酸（TFA）或六氟异丙醇（HFIPA）的加入大大提高了四氯苯醌（CA）对C-3（60）的氧化猝灭速率。这些添加剂具有相似的氢键能力，但它们的质子酸性差异很大。在这两种情况下，猝灭速率常数计算氢键CA急剧增加添加剂浓度。醌周围的氢键簇被假定为电子转移耦合到CA（-）的快速质子化。通过TFA，和强H-键合或通过HFIPA的带电自由基的溶剂化。这与观察到的中性半醌形成、更高的自由基产率和TFA的慢得多的逆反应一致。C-60（+）光谱（在980 nm处λ = 25 000 +/- 2000 M-1 s（-1））在整个可见光区显示低吸收。C-60（+.）的电荷位移反应芳烃的反应遵循Alumm-Weller-Marcus反应动力学，是合成芳醚的有效途径。阳离子自由基使用可见光。
The rate of oxidative quenching of C-3(60) by chloranil (CA) in CH2Cl2 is much enhanced by added trifluoroacetic acid (TFA) or hexafluoro-2-propanol (HFIPA). These additives have similar hydrogen-bonding powers but differ widely in their proton acidities. In both cases, quenching rate constants calculated for H-bonded CA increase sharply with additive concentration. H-bonded clusters around the quinone are postulated in which electron transfer is coupled to fast protonation of CA(-.) by TFA, and strong H-bonding or solvation of charged radicals by HFIPA. This is consistent with observed neutral semiquinone formation, higher radical yields, and much slower back reactions for TFA. The C-60(+.) spectrum (epsilon = 25 000 +/- 2000 M-1 s(-1) at 980 nm) shows low absorption throughout the visible region. Charge-shift reactions Of C-60(+.) and arenes follow Rehm-Weller-Marcus kinetics and afford efficient preparation of arenel(+.) cation radicals using visible light.