Fukuzumi S, Ohkubo K
Department of Material and Life Science, Graduate School of Engineering, Osaka University, CREST, Japan Science and Technology Corporation, Suita.
Chemistry. 2000 Dec 15;6(24):4532-5. doi: 10.1002/1521-3765(20001215)6:24<4532::aid-chem4532>3.0.co;2-9.
The g values of ESR spectra of superoxide-metal ion complexes (O2(-)-Mn+, n = 1, 2, 3) are determined in acetonitrile at 143 K. The binding energies (deltaE) of metal ions with O2- have been evaluated from deviation of the gzz values from the free spin value. The deltaE values are well correlated with the catalytic reactivities of metal ions in electron transfer from cobalt(II) tetraphenylporphyrin to O2 and p-benzoquinone, which does not occur in the absence of metal ions under otherwise the same experimental conditions. The deltaE values can thereby be used as the first quantitative measure for Lewis acidity of metal ions in relation with the catalytic reactivities in electron transfer reactions.
在143K的乙腈中测定了超氧金属离子配合物（O2(-)-Mn+，n = 1, 2, 3）的电子自旋共振（ESR）谱的g值。根据gzz值相对于自由自旋值的偏差评估了金属离子与O2-的结合能（deltaE）。deltaE值与金属离子在从钴（II）四苯基卟啉到O2和对苯醌的电子转移中的催化活性密切相关，在相同实验条件下，若无金属离子则不会发生这种电子转移。因此，deltaE值可作为金属离子路易斯酸度与电子转移反应催化活性相关的首个定量度量。
