Paramagnetic products formed in the reactions of organometallic compounds. XII ESR study of oxido anion substituted diaryl ketyl radicals

✍ Scribed by Ľ. Malik; A. Staško; E. Mat'ašová; A. Tkáč

• Publisher: John Wiley and Sons
• Year: 1981
• Tongue: English
• Weight: 278 KB
• Volume: 15
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1270150117

✦ Synopsis

Abstract

In the reactions of alkyl‐substituted‐benzenecarboxylic and ‐2‐hydroxybenzenecarboxylic acids (ArCOOH) with alkyl‐substituted phenyl Grignard reagents (RMgX) in the presence of nickel, ketyl radicals ArCO^−^R are formed. The para substituents (H, Me, Et, Isopr and t‐Bu) of R increase the non‐equivalence of its ortho protons (a change of a~2~^H^ = 0.43 mT, a~6~^H^ = 0.422 mT to 0.435 mT, 0.395mT respectively, on substituting t‐butyl for H at position 4). The oxido anion group originating from 2‐hydroxybenzenecarboxylic acid has a strong push effect and nearly doubles the unpaired spin density on the phenyl ring R.