Activation of electron-transfer reduction of oxygen by hydrogen bond formation of superoxide anion with ammonium ion.
Activation of electron-transfer reduction of oxygen by hydrogen bond formation of superoxide anion with ammonium ion.
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DOI：
10.1021/jp064115m
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发表时间：
2006-10
期刊：
影响因子：
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通讯作者：
K. Ohkubo;H. Kitaguchi;S. Fukuzumi
中科院分区：
文献类型：
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作者：
K. Ohkubo;H. Kitaguchi;S. Fukuzumi
超氧阴离子和铵离子(NH4+)之间形成的氢键显着加速了从C60自由基阴离子到氧的电子转移，而四正丁基铵离子没有能力与超氧阴离子形成氢键，没有表现出加速氧的电子转移还原。从 C60*- 到 O2 的电子转移二阶速率常数随着 NH4+ 浓度的增加而线性增加。这表明从 C60 到 O2 的电子转移中产生的 O2*- 通过 O2*- 和 NH4+ 之间形成 1:1 络合物而稳定。 ESR 检测到 O2*- 和 NH4+ 之间形成的 1:1 复合物。 O2*- 与 NH4+ 的结合导致 O2 的还原电位随着 NH4+ 浓度的增加而正向移动，导致电子从 C60*- 向 O2 的转移加速。
A hydrogen bond formed between the superoxide anion and the ammonium ion (NH4+) accelerates electron transfer from the C60 radical anion to oxygen significantly, whereas the tetra-n-butylammonium ion has no ability to form a hydrogen bond with the superoxidie anion, exhibiting no acceleration of the electron-transfer reduction of oxygen. The second-order rate constant of electron transfer from C60*- to O2 increases linearly with increasing concentration of NH4+. This indicates that O2*- produced in the electron transfer from C60 to O2 is stabilized by 1:1 complex formation between O2*- and NH4+. The 1:1 complex formed between O2*- and NH4+ was detected by ESR. The binding of O2*- with NH4+ results in a positive shift of the reduction potential of O2 with increasing concentration of NH4+, leading to the acceleration of electron transfer from C60*- to O2.