Structural Effects in the Iridium Complex Series: Photoredox Catalysis and Photoinitiation of Polymerization Reactions under Visible Lights. Issue 18 (10th July 2017)

• Record Type: Journal Article
• Authors: Tehfe, Mohamad‐Ali; Lepeltier, Marc; Dumur, Frédéric; Gigmes, Didier; Fouassier, Jean‐Pierre; Lalevée, Jacques
• Other Names: Tunca Umit guestEditor.
• Is Part Of: Macromolecular chemistry and physics. Volume 218:Issue 18(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-07-10
• Subjects: free radical polymerization -- iridium complexes -- LED -- photopolymerization -- ring‐opening cationic polymerization (ROP); Polymers -- Periodicals; Polymerization -- Periodicals; Synthetic products -- Periodicals; Macromolecules -- Periodicals; 547.7
• DOI: 10.1002/macp.201700192
• Languages: English
• ISSNs: 1022-1352

Abstract

Abstract : A series of iridium complexes are prepared and studied. These photoinitiating systems operate through an oxidative or a reductive photoredox catalytic cycle, respectively. Excellent polymerization profiles are obtained. The photochemical mechanisms are studied by fluorescence, steady state photolysis, cyclic voltammetry, and electron spin resonance spin trapping experiments. Abstract : A series of 18 iridium complexes (Ir ) have been prepared and studied. Their abilities to initiate both a ring‐opening cationic polymerization (CP) using anIr /iodonium salt couple and a free radical polymerization (FRP) in the presence of anIr /amine/alkyl halide system under very soft irradiation (i.e., halogen lamp) or upon exposure to laser diodes @457 nm and @532 nm are investigated. Interestingly, these photoinitiating systems operate through an oxidative or a reductive photoredox catalytic cycle, respectively. Excellent polymerization profiles are obtained (reactive function conversions >70% for the CP of an epoxide and >60% for the FRP of low viscosity triacrylate). The photochemical mechanisms are studied by fluorescence, steady state photolysis, cyclic voltammetry, and electron spin resonance spin trapping experiments.