skip to main content
Lingue:

Electron-transfer reaction of cinnamic acids and their methyl esters with the DPPH(*) radical in alcoholic solutions

Foti, Mario C ; Daquino, Carmelo ; Geraci, Corrada

The Journal of organic chemistry, 02 April 2004, Vol.69(7), pp.2309-14 [Rivista Peer Reviewed]

Accesso online

Vedi tutte le versioni
Citazioni Citato da
  • Titolo:
    Electron-transfer reaction of cinnamic acids and their methyl esters with the DPPH(*) radical in alcoholic solutions
  • Autore: Foti, Mario C ; Daquino, Carmelo ; Geraci, Corrada
  • Descrizione: The kinetic behavior of cinnamic acids, their methyl esters, and two catechols 1-10 (ArOH) in the reaction with DPPH(*) in methanol and ethanol is not compatible with a reaction mechanism that involves hydrogen atom abstraction from the hydroxyl group of 1-10 by DPPH(*). The rate of this reaction at 25 degrees C is, in fact, comparatively fast despite that the phenolic OH group of ArOH is hydrogen bonded to solvent molecules. The observed rate constants (k(1)) relative to DPPH(*) + ArOH are 3-5 times larger for the methyl esters than for the corresponding free acids and, for the latter, decrease as their concentration is increased according to the relation k(1) = B/[ArOH](0)(m), where k(1) is given in units of M(-1) s(-1), m is ca. 0.5, and B ranges from 0.02 (p-coumaric acid) to ca. 3.48 (caffeic acid) in methanol and from 0.04 (p-coumaric acid) to ca. 13 (sinapic acid) in ethanol. Apparently, the reaction mechanism of DPPH(*) + ArOH involves a fast electron-transfer process from the phenoxide...
  • Fa parte di: The Journal of organic chemistry, 02 April 2004, Vol.69(7), pp.2309-14
  • Soggetti: Cinnamates -- Chemistry ; Methane -- Chemistry ; Picrates -- Chemistry
  • Lingua: Inglese
  • Identificativo: ISSN: 0022-3263 ; PMID: 15049623 Version:1

Ricerca in corso nelle risorse remote ...