THE PHOTOELECTROCHEMICAL REDUCTION OF PYRENE IN ACETONITRILE SOLUTION

Journal article

The reduction of pyrene (Py) at a mercury channel electrode is studied in acetonitrile solution, both in the dark and under conditions where the pyrene radical anion (Py-.) is photoexcited, using a wavelength of 501.7 nm. In the dark a reversible one-electron process occurs forming the radical anion. However, upon photoexcitation of the electrogenerated radical anion, photocurrents are observed, and the precise electrode mechanism is shown to be: {A figure is presented} The photocurrent arising from further reduction of Py, since rapid homogeneous reactions of Py-2 give electroinactive products. With this scheme an "effective" second order decay of Py-{radical dot} is observed, rate = -keff[Py-{radical dot}]p2 where keff is proportional to k3 I/kf. keff has been evaluated from analysis of the limiting current-flow rate behaviour at the channel electrode at the channel electrode. This was found to be 4.0 ± 0.1 × 103 mol-1 dm3 s-1 at a light intensity of 0.30 W cm-2 and a pyrene concentyration of 2.97 mM. © 1990.

Authors: Waller, A; Compton, R

• Publication status: Published
• Journal: ELECTROCHIMICA ACTA
• Volume: 35
• Issue: 11-12
• Pages: 1837-1839
• Publication date: 1990-01-01
• DOI: 10.1016/0013-4686(90)87087-I
• ISSN: 0013-4686
• Language: English