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Light‐Regulated Polymerization under Near‐Infrared/Far‐Red Irradiation Catalyzed by Bacteriochlorophyll a
Author(s) -
Shanmugam Sivaprakash,
Xu Jiangtao,
Boyer Cyrille
Publication year - 2016
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201510037
Subject(s) - photochemistry , polymerization , chain transfer , irradiation , chemistry , polymer , bacteriochlorophyll , visible spectrum , radical polymerization , materials science , optoelectronics , organic chemistry , physics , nuclear physics , pigment
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.