L. Kress et al., IN-SITU SPECTROELECTROCHEMISTRY OF 2,5-DIPHENYL-1,3,4-OXADIAZOLE, Journal of electroanalytical chemistry [1992], 414(1), 1996, pp. 31-40
The electrochemical reduction of 2,5-diphenyl-1,3,4-oxadiazole has bee
n studied by both cyclic voltammetry and spectroelectrochemistry. The
in situ spectroscopic techniques were applied to obtain structural inf
ormation on the products of the follow-up reactions. Time-resolved UV-
vis spectroscopy, with spectra measured on a time scale of 20 ms by a
diode array spectrometer, was used in cyclic voltammetry to obtain up
to 60 single spectra in the forward and backward scans. The radical an
ion of 2,5-diphenyl-1,3,4-oxadiazole, which is formed in the electron
transfer reaction at the electrode, was studied by ESR spectroscopy. F
urthermore, paramagnetic products of the follow-up reactions were dete
cted. A reaction mechanism is formulated that includes an irreversible
protonation reaction and, in parallel, a reversible ion-pairing react
ion with the supporting electrolyte cation for the electrochemically g
enerated radical anion and an irreversible follow-up reaction for the
dianion of 2,5-diphenyl-1,3,4-oxadiazole.