Elucidation of phenol-Cu interaction mechanisms by potentiometry, ESR, UV absorption spectroscopy and molecular simulations

Article Article scientifique Article Elucidation of phenol-Cu interaction mechanisms by potentiometry, ESR, UV absorption spectroscopy and molecular simulations eng 1999-03 author Oess Andréa Helena 27624 author Cheshire Martin V. author McPhail Donald B. author Stoll Serge 0000-0003-3158-4208 29148 Forel Communs (FOREL) author El Alaili Mazen author Vedy Jean-Claude 49-58 10.1016/S0048-9697(99)00029-7 0048-9697 In order to determine the dominant properties, which control the interactions of monomeric hydrosoluble phenols with Cu2+ in soil solutions, four different techniques were used. CuSO4 was added to ortho-dihydroxy-phenol (ODP) solutions under controlled temperature, pH, and ionic strength conditions and Cu2+-ODP interactions were studied by alkaline potentiometric titrations, electron spin resonance and UV absorption. Molecular dynamic simulations were also performed for conformational studies. From the titration curves, the shifts in isotropic A and g values, the evolution of the UV absorption band at 400 nm and the calculation of the potential energy of the different complexes, a three-step interaction mechanism was proposed. In the process an inner-sphere complex was formed, Cu(II) is being reduced and an oxydative polymerisation chain reaction initiated. The driving force of the reaction was the energetic stability obtained upon interaction of Cu2+ with the substrate. The ideal conformation was reached at the catechol site and not at carboxylic or hydroxy–methoxy sites. The pKa values of the phenols had little influence on the interaction process but the type and number of interacting sites on the benzene ring influenced the proceeding of progress of the reaction. Increasing the pH of the solution increased the amount of complexed species, but also the number of ligands around the Cu2+ion. Cu complexation Phenols PH Potentiometric titration ESR Molecular simulations UV spectroscopy Dewey 540 40 Département de chimie minérale, analytique et appliquée 145 false Science of the total environment 228 1 b1262516-0d76-44d3-a90e-9a24bda67d03 Article (Published version) Restricted Oess_STE_199922849.pdf 432112 application/pdf 5a08b93d3b3644ce6ad2d4889fd0ef9ed7fce3bbab136bb4731bed9d9aeb4fcd restrictedAccess Faculté des sciences / Section de chimie et biochimie / Département de chimie minérale, analytique et appliquée

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Elucidation of phenol-Cu interaction mechanisms by potentiometry, ESR, UV absorption spectroscopy and molecular simulations	Science of the total environment			1999	94	0

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Oess, Andréa Helena