Intramolecular, intermolecular, and heterogeneous nonadiabatic dissociative electron transfer to peresters

被引:54
作者
Antonello, S
Formaggio, F
Moretto, A
Toniolo, C
Maran, F
机构
[1] Univ Padua, Dept Phys Chem, I-35131 Padua, Italy
[2] Univ Padua, Dept Organ Chem, CNR, Biopolymer Res Ctr, I-35131 Padua, Italy
关键词
D O I
10.1021/ja010799u
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
The electron transfer to peresters was studied by electrochemical means in N,N-dimethylformamide. The reduction was carried out by three independent methods: (i) heterogeneously, by using glassy carbon electrodes, (ii) homogeneously, by using electrogenerated radical anions as the donors, and (iii) intramolecularly, by using purposely synthesized donor-spacer-acceptor (D-Sp-A) systems. Convolution analysis of the heterogeneous data led to results in excellent agreement with the dissociative electron transfer theory. The homogeneous redox catalysis data also confirmed the reduction mechanism. The cyclic voltammetries of the D-Sp-A molecules could be simulated, leading to determination of the corresponding intramolecular dissociative rate constants. Analysis of the results showed that, regardless of the way by which the acceptor is reduced, the investigated dissociative electron transfers are strongly nonadiabatic and, particularly, that the experimental rates are several orders of magnitude smaller than the adiabatic limit. A possible mechanism responsible for the observed behavior is discussed.
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收藏
页码:9577 / 9584
页数:8
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