Premium
Structural Effects in the Iridium Complex Series: Photoredox Catalysis and Photoinitiation of Polymerization Reactions under Visible Lights
Author(s) -
Tehfe MohamadAli,
Lepeltier Marc,
Dumur Frédéric,
Gigmes Didier,
Fouassier JeanPierre,
Lalevée Jacques
Publication year - 2017
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.201700192
Subject(s) - photochemistry , polymerization , cationic polymerization , chemistry , iridium , spin trapping , photoredox catalysis , photopolymer , polymer chemistry , ring opening polymerization , polymer , radical , catalysis , photocatalysis , organic chemistry
A series of 18 iridium complexes ( Ir ) have been prepared and studied. Their abilities to initiate both a ring‐opening cationic polymerization (CP) using an Ir /iodonium salt couple and a free radical polymerization (FRP) in the presence of an Ir /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.