KINETICS OF THE ANODIC DIMERIZATION OF 4,4'-DIMETHOXYSTILBENE BY THE ROTATING-RING-DISK ELECTRODE

The mechanism of anodic coupling of 4, 4ʹ-dimethoxystilbene (DMOS) has been studied with the rotating ring-disk electrode (RRDE). DMOS is oxidized at +0.92 V vs. SCE in a one-electron transfer to its radical cation (DMOS+•). Simulation of the RRDE results shows that DMOS1• dimerizes in 0.1 M lithium perchlorate-acetonitrile mainly by a radical pathway with k2 = 1.59 × 104 M-1 s-1. As the minor parallel reaction, an ECE mechanism has to be assumed with electrophilic attack of DMOS+• at either DMOS = 5 × 103 M-1 s-1) or water (cH2Ok3 = 7 s-1)•. © 1979, American Chemical Society. All rights reserved.