Elucidation of the Key Role of [Ru(bpy)3 ](2+) in Photocatalyzed RAFT Polymerization.
Fiche publication
Date publication
août 2016
Journal
Chemphyschem : a European journal of chemical physics and physical chemistry
Auteurs
Membres identifiés du Cancéropôle Est :
Pr ALLONAS Xavier
Tous les auteurs :
Christmann J, Ibrahim A, Charlot V, Croutxé-Barghorn C, Ley C, Allonas X
Lien Pubmed
Résumé
Photocatalysis reactions using [Ru(II) (bpy)3 ](2+) were studied on the example of visible-light-sensitized reversible addition-fragmentation chain transfer (RAFT) polymerization. Although both photoinduced electron- and energy-transfer mechanisms are able to describe this interaction, no definitive experimental proof has been presented so far. This paper investigates the actual mechanism governing this reaction. A set of RAFT agents was selected, their redox potentials measured by cyclic voltammetry, and relaxed triplet energies calculated by quantum mechanics. Gibbs free-energy values were calculated for both electron- and energy-transfer mechanisms. Quenching rate constants were determined by laser flash photolysis. The results undoubtedly evidence the involvement of a photoinduced energy-transfer reaction. Controlled photopolymerization experiments are discussed in the light of the primary photochemical process and photodissociation ability of RAFT agent triplet states.
Référence
Chemphyschem. 2016 Aug 4;17(15):2309-14