title: Light-Regulated Polymerization under Near-Infrared/Far-Red Irradiation Catalyzed by Bacteriochlorophyll a.
abstract: Photoregulated polymerizations are typically conducted using high-energy (UV and blue) light, which may lead to undesired side reactions. Furthermore, as the penetration of visible light is rather limited, the range of applications with such wavelengths is likewise limited. We herein report the first living radical polymerization that can be activated and deactivated by irradiation with near-infrared (NIR) and far-red light. Bacteriochlorophyll a (Bachl a) was employed as a photoredox catalyst for photoinduced electron transfer/reversible addition-fragmentation chain transfer (PET-RAFT) polymerization. Well-defined polymers were thus synthesized within a few hours under NIR (λ=850 nm) and far-red (λ=780 nm) irradiation with excellent control over the molecular weight (M(n)/M(w)<1.25). Taking advantage of the good penetration of NIR light, we showed that the polymerization also proceeded smoothly when a translucent barrier was placed between light source and reaction vessel.
authors.affiliation: Centre for Advanced Macromolecular Design and Australian Centre for NanoMedicine, School of Chemical Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia.
authors.forename: Sivaprakash
authors.initials: S
authors.lastname: Shanmugam
authors.affiliation: Centre for Advanced Macromolecular Design and Australian Centre for NanoMedicine, School of Chemical Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia.
authors.forename: Jiangtao
authors.initials: J
authors.lastname: Xu
authors.affiliation: Centre for Advanced Macromolecular Design and Australian Centre for NanoMedicine, School of Chemical Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia. cboyer@unsw.edu.au.
authors.forename: Cyrille
authors.initials: C
authors.lastname: Boyer
mesh_terms: D025541:Bacteriochlorophyll A / Q000737:chemistry*; D002384:Catalysis; D007259:Infrared Rays; D008027:Light; D058105:Polymerization
chemical_list: D025541:Bacteriochlorophyll A
keywords: RAFT polymerization; bacteriochlorophyll; controlled radical polymerization; photocatalysis; photoinduced electron transfer