TCE

The Chemical Educator

ISSN: 1430-4171 (electronic version)

Table of Contents

Abstract Volume 6 Issue 6 (2001) pp 343-349

Voltammetric Reductions of Ring-Substituted Acetophenones. 1. Determination of an Electron-Transfer Mechanism Using Cyclic Voltammetry and Computer Modeling: The Formation and Fate of a Radical Anion.

Grant N. Holder*, David G. Farrar and Laurel L. McClure

A. R. Smith Department of Chemistry, Appalachian State University, Boone, NC 28608
Received July 12, 2001. Accepted August 27, 2001

Published online: 16 November 2001

Abstract. In a sophomore/junior-level experiment suitable for intermediate organic or instrumental analysis, ring-substituted acetophenones were electrochemically reduced to form radical anions that then decompose in a manner determined by the ring substituent. Cyclic voltammetry was used to identify the electron-transfer (ET) mechanism, which was an electron transfer followed by a chemical reaction (EC). The product of the reaction was often electroactive (ECE) in the potential window defined by the acetonitrile/Bu₄NPF₆ solvent/supporting electrolyte. Products of the following decomposition were estimated with computer modeling (DFT) to estimate the likelihood of various decomposition pathways. Selection of the ring substituent or switching potential (E_sw) allows the instructor to ask students to assign the mechanism for a single reduction or a complete ET mechanism, matching the difficulty of this experiment to the level of audience preparation.

Key Words:  Laboratories and Demonstrations; organic chemistry; instrumental analysis; cyclic voltammetry

(*) Corresponding author. (E-mail: holdergn@appstate.edu)

Article in PDF format (242 KB) HTML format

Supporting Materials:

Issue date: December 7, 2001

© The Chemical Educator 1996-2024