Metal-Free ATRP Catalyzed by Visible Light in Continuous Flow

Abstract

ATRP of methyl methacrylate catalyzed by Eosin Y, an inexpensive and an environmental benign dye, was performed in a continuous flow reactor made of FEP tubing and irradiated by visible light green LEDs. The reaction under flow conditions was significantly more rapid and controlled compared to that in batch giving 90% of polymerization after only 3 h of irradiation. The formed polymers in flow have M n measured by GPC and DOSY NMR in accordance with the theoretical values and show low dispersities (Ð < 1.5). The livingness of the polymers has been confirmed by LED on and LED off experiments and by the synthesis of block copolymers. The protocol described herein serves as a “proof of concept” of using Eosin Y as a photocatalyst for controlled polymerization and of using 1D and 2D NMR for polymer characterization. The protocol could be replicated in the future for other reversible-deactivation radical polymerizations.

Photoinduced Organocatalyzed Atom Transfer Radical Polymerization (O-ATRP): Precision Polymer Synthesis Using Organic Photoredox Catalysis

“…Expanding on the scope of O-ATRP in flow, Rolando and co-workers showed eosin Y could also be employed with this reactor design. In the polymerization of MMA, this system gave moderate polymerization control, with good I * ( I * ∼ 100%) and moderate dispersity ( Đ ∼ 1.4) . In addition, others have shown a wide range of monomers can be polymerized using O-ATRP in flow, such as methacrylates, methacrylic acid (Figure d), acrylates (Figure e), and styrene …”

“…In the polymerization of MMA, this system gave moderate polymerization control, with good I* (I* ∼ 100%) and moderate dispersity (Đ ∼ 1.4). 236 In addition, others have shown a wide range of monomers can be polymerized using O-ATRP in flow, such as methacrylates, 155 methacrylic acid (Figure 44d), 170 acrylates (Figure 44e), 65 and styrene. 92…”

Cu‐Catalyzed Atom Transfer Radical Polymerization: The Effect of Cocatalysts

“…[ 131 ] The reduction of Cu II /PMDETA was confirmed by laser flash photolysis. Dyes. In many cases, dyes (e.g., Eosin Y [ 132,133 ] and fluorescein [ 132 ] ) were usually used in metal‐free ATRP. But these dyes were also applied to Cu‐catalyzed ATRP, with better control over the polymerization afforded by Cu II complexes.…”

Assemblies of Polyacrylonitrile-Derived Photoactive Polymers as Blue and Green Light Photo-Cocatalysts for Cu-Catalyzed ATRP in Water and Organic Solvents

“…Similar to other externally controlled CRP methods ( Chmielarz et al, 2017 ; Mohapatra et al, 2017 ; Wang et al, 2017 ; Pan et al, 2018 ), photoinduced CRPs exhibit many advantages, such as excellent temporal control. In particular, photoinduced atom transfer radical polymerization (ATRP) ( Wang and Matyjaszewski, 1995 ; Matyjaszewski and Xia, 2001 ; Matyjaszewski, 2012 ; Dadashi-Silab et al, 2014 ; Matyjaszewski and Tsarevsky, 2014 ; Theriot et al, 2016 ; Matyjaszewski, 2018 ; Lorandi and Matyjaszewski, 2020 ) and reversible addition-fragmentation chain-transfer (RAFT) polymerization ( Xu et al, 2015 ; Pearson et al, 2016 ; Perrier, 2017 ; Allegrezza and Konkolewicz, 2021 ) have largely benefited from the development of OPCs, such as phenothiazine derivatives ( Treat et al, 2014 ; Pan et al, 2016b ; Theriot et al, 2016 ; Dadashi-Silab et al, 2021 ), eosin Y ( Kutahya et al, 2016 ; El Achi et al, 2020 ) and halogenated xanthene dyes ( Wu et al, 2019 ). Besides small-molecule OPCs, OPNOs have been applied in photoinduced CRP ( Jiang et al, 2018 ; Kütahya et al, 2020 ; Hao et al, 2021 ; Kütahya et al, 2021 ).…”