Photo-degradation of trans-caffeic acid in aqueous solution and influence of complexation by metal ions
type: Dataset
description: The photo-degradation of metal complexes of caffeic acid was compared to the photo-degradation of free caffeic acid by using UV-vis spectroscopy and HPLC-ESI-mass spectrometry. This article reports first the determination of the products that are formed from the photo-degradation of trans-caffeic acid in aqueous solution and the investigation of the mechanism by a kinetic approach. The good fit between the model and the experimental concentration profiles confirms the photo-isomerization route of the molecule to cis-caffeic acid which then undergoes a cyclization to form the esculetin photo-product. In addition, it reveals, for the first time, another route of major importance leading to the product vinylcatechol. The presence of oxygen leads to an increase of the photo-isomerization rate. Then we report that metallic cations such as Al(III), Pb(II) and Cu(II) can influence the rate and mechanism of caffeic acid photo-degradation. Al(III) ions slow down the photo-degradation whereas Pb(II) and Cu(II) ions have a promoter effect on the production of esculetin. In all cases, the photo-isomerization is reduced by the presence of metal ions and the formation of vinylcatechol does not occur.
issued: 2026-05-10T16:32:49.995221
language: en
modified: 2026-05-10T16:32:49.995224
contact point: Organization
  fn: CCSD
keyword: caffeic-acid
keyword: chimtheochemical-sciencestheoretical-andor-physical-chemistry
keyword: humic-substances
keyword: infoeu-reposemanticsarticle
keyword: journal-articles
keyword: kinetics
keyword: mechanism
keyword: metal-complex
keyword: photo-degradation
landing page: 1010-6030

Photo-degradation of trans-caffeic acid in aqueous solution and influence of complexation by metal ions
type: Distribution
format: HTML
issued: 2026-05-10T16:32:50.008709
modified: 2026-05-10T16:32:49.984231
access URL: https://hal.science/hal-00835301

test_moissonnage_selune
type: Agent