Metal and metal-free photocatalysts: mechanistic approach and application as photoinitiators of photopolymerization.
In the present paper, the photoredox catalysis is presented as a unique approach in the field of photoinitiators of polymerization. The principal photocatalysts already reported as well as the typical oxidation and reduction agents used in both reductive or oxidative cycles are gathered. The chemical mechanisms associated with various systems are also given. As compared to classical iridium-based photocatalysts which are mainly active upon blue light irradiation, a new photocatalyst Ir(piq)2(tmd) (also known as bis(1-phenylisoquinolinato-N,C (2'))iridium(2,2,6,6-tetramethyl-3,5-heptanedionate) is also proposed as an example of green light photocatalyst (toward the long wavelength irradiation). The chemical mechanisms associated with Ir(piq)2(tmd) are investigated by ESR spin-trapping, laser flash photolysis, steady state photolysis, cyclic voltammetry and luminescence experiments.
Institut de Science des Matériaux de Mulhouse IS2M - UMR CNRS 7361 -UHA; 15 rue Jean Starcky, 68057 Mulhouse Cedex, France.
Jacques
J
Lalevée
Institut de Science des Matériaux de Mulhouse IS2M - UMR CNRS 7361 -UHA; 15 rue Jean Starcky, 68057 Mulhouse Cedex, France.
Sofia
S
Telitel
Institut de Science des Matériaux de Mulhouse IS2M - UMR CNRS 7361 -UHA; 15 rue Jean Starcky, 68057 Mulhouse Cedex, France.
Pu
P
Xiao
Institut Lavoisier de Versailles, UMR 8180 CNRS, Université de Versailles Saint-Quentin en Yvelines, 45 avenue des Etats-Unis, 78035 Versailles Cedex, France.
Marc
M
Lepeltier
Aix-Marseille Université, CNRS, Institut de Chimie Radicalaire, UMR 7273, F-13397 Marseille, France ; Univ. Bordeaux, IMS, UMR 5218, F-33400 Talence, France ; CNRS, IMS, UMR 5218, F-33400 Talence, France.
Frédéric
F
Dumur
Institut de Science des Matériaux de Mulhouse IS2M - UMR CNRS 7361 -UHA; 15 rue Jean Starcky, 68057 Mulhouse Cedex, France.
Fabrice
F
Morlet-Savary
Aix-Marseille Université, CNRS, Institut de Chimie Radicalaire, UMR 7273, F-13397 Marseille, France.
Didier
D
Gigmes
formerly: University of Haute Alsace/ENSCMu, 3 rue Alfred Werner, 68093 Mulhouse Cedex, France.
Jean-Pierre
JP
Fouassier
LEDs; photoinitiators; photopolymerization; photoredox catalysis