Photoredox catalysis using a new iridium complex as an efficient toolbox for radical, cationic and controlled polymerizations under soft blue to green lights. Issue 4 (2nd December 2014)

• Record Type: Journal Article
• Authors: Telitel, Sofia; Dumur, Frederic; Telitel, Siham; Soppera, Olivier; Lepeltier, Marc; Guillaneuf, Yohann; Poly, Julien; Morlet-Savary, Fabrice; Fioux, Philippe; Fouassier, Jean-Pierre; Gigmes, Didier; Lalevée, Jacques
• Is Part Of: Polymer chemistry. Volume 6:Issue 4(2015)
• Page Start: 613
• Page End: 624
• Publication Date: 2014-12-02
• Subjects: Polymers -- Periodicals; Macromolecules -- Periodicals; Polymerization -- Periodicals; 547.705
• DOI: 10.1039/c4py01358a
• Languages: English
• ISSNs: 1759-9954

Abstract

Abstract : A new iridium complex (nIr ) was designed and investigated as a photoinitiator catalyst for radical and cationic polymerizations upon very soft irradiation. Abstract : A new iridium complex (nIr ) was designed and investigated as a photoinitiator catalyst for radical and cationic polymerizations upon very soft irradiations (lights ranging from 457 to 532 nm). A ring-opening polymerization (ROP) of an epoxy monomer was easily promoted through the interaction betweennIr and an iodonium salt (Iod) upon light. The addition of N -vinylcarbazole (NVK) enhances the performance. In radical polymerization, nIr can be efficient in combination with phenacyl bromide (PBr) and optionally an amine: these photoinitiating systems work according to an original oxidative cycle and a regeneration ofnIr is observed. A control of the methyl methacrylate polymerization (conducted under a 462 nm light) with 1.2–1.6 polydispersity indexes was displayed. Surface modifications by direct laser write was also easily carried out for the first time through surface re-initiation experiments, i.e. the dormant species being reactivated by light in the presence ofnIr ; the polymer surfaces were analyzed by XPS. The chemical mechanisms were examined through laser flash photolysis, NMR, ESR and size exclusion chromatography experiments.