W. M. Leslie, R. Compton, T. Silk
Mar 15, 1997
Citations
0
Influential Citations
9
Citations
Journal
Journal of Electroanalytical Chemistry
Abstract
Abstract The dual photo- and electro-chemical activation of benzophenone and the 4-halobenzophenones, 4-XC6H4COOPh (X F, Cl) in acetonitrile solution using channel electrode methodology is reported. In the cases of benzophenone and 4-fluorobenzophenone one-electron reduction leads to the formation of the corresponding radical anions which are stable in the absence of light. Irradiation using light of wavelength 325 nm induced significant photocurrents to pass; this was interpreted in terms of a light-induced disproportionation reaction, initially generating the parent material and the corresponding di-anion, with the latter ultimately leading to the formation of the corresponding alcohols, C6H5CH(OH)Ph and FC6H4CH(OH)Ph. The processes are shown to follow DISP2 mechanisms, in which there is both a significant fraction of back reaction (conproportionation) and also quenching of the photo-excited state of the radical anion by the parent material. In contrast, the reduction of 4-chlorobenzophenone at − 1.61 V (vs. Ag) was found to be accompanied by only tiny photo-currents on irradiation with light of wavelength 325 nm.