THIN-LAYER SPECTROELECTROCHEMISTRY FOR MONITORING KINETICS OF ELECTROGENERATED SPECIES

The applicability of thin-layer optically transparent electrodes for monitoring homogeneous chemical reactions of electro-generated species has been demonstrated. The reactive species is coulometrically generated in the thin solution layer at a minigrid electrode, and the chemical reaction is optically monitored by light passing through the transparent electrode. Single- and double-potential step techniques are demonstrated using the benzidine rearrangement as a model system. Spectra in the 200-320 nm range were obtained with a rapid scanning spectrometer during electrogeneration and reaction. Absorbance vs. time data were then displayed for analysis of the kinetics. Rate constants obtained for the acid-catalyzed benzidine rearrangement were 2.8 10-3 s-1 in 0.05 F HCI and 3.0 10-2 s-1 in 0.10 F HCI. © 1979, American Chemical Society. All rights reserved.