Photochemical Generation and Structure of Vinyl Radicals

✍ Scribed by Theodorus P. M. Goumans; Kaj van Alem; Gerrit Lodder

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 221 KB
• Volume: 2008
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/ejoc.200700882

✦ Synopsis

Abstract

Photolysis of a series of E or Z stereoisomeric α‐R‐substituted bromostyrenes (R = CH~3~, F or CN) in methanol yields E and/or Z stereoisomeric styrenes, which stem from the corresponding vinyl radicals. The results show that the α‐Me vinyl radical is a rapidly equilibrating, bent structure, while the α‐F vinyl radical is a stable bent species, in agreement with earlier thermal results. The α‐CN vinyl radical is assigned as a rapidly inverting bent and not a linear species from the stereochemical results as a function of temperature. Stereochemical data for the α‐C(H)=O system in diethyl ether indicate a stable bent vinyl radical as product forming species. The conclusions are supported by quantum chemical computations.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)