Solvent Effects and Side Reactions in Organocatalyzed Atom Transfer Radical Polymerization for Enabling the Controlled Polymerization of Acrylates Catalyzed by Diaryl Dihydrophenazines
- PMID: 34267405
- PMCID: PMC8276882
- DOI: 10.1021/acs.macromol.0c02245
Solvent Effects and Side Reactions in Organocatalyzed Atom Transfer Radical Polymerization for Enabling the Controlled Polymerization of Acrylates Catalyzed by Diaryl Dihydrophenazines
Abstract
Investigation of the effects of a solvent on the photophysical and redox properties of the photoredox catalyst (PC), N,N-di(2-naphthyl)-5,10-dihydrophenazine (PC 1), revealed the opportunity to use tetrahydrofuran (THF) to modulate the reactivity of PC 1 toward achieving a controlled organocatalyzed atom transfer radial polymerization (O-ATRP) of acrylates. Compared with dimethylacetamide (DMAc), in tetrahydrofuran (THF), PC 1 exhibits a higher quantum yield of intersystem crossing (ΦISC = 0.02 in DMAc, 0.30 in THF), a longer singlet excited-state lifetime (τ Singlet = 3.81 ns in DMAc, 21.5 ns in THF), and a longer triplet excited-state lifetime (τ Triplet = 4.3 μs in DMAc, 15.2 μs in THF). Destabilization of 1 •+, the proposed polymerization deactivator, in THF leads to an increase in the oxidation potential of this species by 120 mV (E 1/2 0 = 0.22 V vs SCE in DMAc, 0.34 V vs SCE in THF). The O-ATRP of n-butyl acrylate (n-BA) catalyzed by PC 1 proceeds in a more controlled fashion in THF than in DMAc, producing P(n-BA) with low dispersity, Đ (Đ < 1.2). Model reactions and spectroscopic experiments revealed that two initiator-derived alkyl radicals add to the core of PC 1 to form an alkyl-substituted photocatalyst (2) during the polymerization. PC 2 accesses a polar CT excited state that is ~40 meV higher in energy than PC 1 and forms a slightly more oxidizing radical cation (E 1/2 0 = 0.22 V for 1 •+ and 0.25 V for 2 •+ in DMAc). A new O-ATRP procedure was developed wherein PC 1 is converted to 2 in situ. The application of this method enabled the O-ATRP of a number of acrylates to proceed with moderate to good control (Đ = 1.15-1.45 and I* = 83-127%).
Conflict of interest statement
The authors declare no competing financial interest.
Figures
References
-
- Matyjaszewski K; Tsarevsky NV Macromolecular Engineering by Atom Transfer Radical Polymerization. J. Am. Chem. Soc 2014, 136, 6513–6533. - PubMed
- Braunecker WA; Matyjaszewski K Controlled/Living Radical Polymerization: Features, Developments, and Perspectives. Prog. Polym. Sci 2007, 32, 93–146.
- Kamigaito M; Ando T; Sawamoto M Metal-Catalyzed Living Radical Polymerization. Chem. Rev 2001, 101, 3689–3746. - PubMed
-
- Pan X; Fantin M; Yuan F; Matyjaszewski K Externally controlled atom transfer radical polymerization. Chem. Soc. Rev 2018, 47, 5457–5490. - PubMed
- Liebfarth FA; Mattson KM; Fors BP; Collins HA; Hawker CJ External Regulation of Controlled Polymerizations. Angew. Chem., Int. Ed 2013, 52, 199–210. - PubMed
-
- Parkatzidis K; Wang HS; Truong NP; Anastasaki A Recent Developments and Future Challenges in Controlled Radical Polymerization: A 2020 Update. Chem 2020, 6, 1575–1588.
- Corrigan N; Boyer C 100th Anniversary of Macromolecular Science Viewpoint: Photochemical Reaction Orthogonality in Modern Macromolecular Science. ACS Macro Lett. 2019, 8, 812–818. - PubMed
- Corrigan N; Yeow J; Judzewitsch P; Xu J; Boyer C Seeing the Light: Advancing Materials Chemistry through Photo-polymerization. Angew. Chem., Int. Ed 2019, 58, 5170–5189. - PubMed
- Chen M; Zhong M; Johnson JA Light-controlled living radical polymerization: mechanisms, methods, and applications. Chem. Rev 2016, 116, 10167–10211. - PubMed
- Corrigan N; Shanmugam S; Xu J; Boyer C Photocatalysis in Organic Polymer Synthesis. Chem. Soc. Rev 2016, 45, 6165–6212. - PubMed
-
- Miyake GM; Theriot JC Perylene as an Organic Photocatalyst for the Radical Polymerization of Functionalized Vinyl Monomers through Oxidative Quenching with Alkyl Bromides and Visible Light. Macromolecules 2014, 47, 8255–8261.
- Treat NJ; Sprafke H; Kramer JW; Clark PG; Barton BE; de Alaniz JR; Fors BP; Hawker CJ Metal-free atom transfer radical polymerization. J. Am. Chem. Soc 2014, 136, 16096–16101. - PubMed
- Discekici EH; Anastasaki A; Read de Alaniz J; Hawker CJ Evolution and Future Directions of Metal-Free Atom Transfer Radical Polymerization. Macromolecules 2018, 51, 7421–7434.
-
- Theriot JC; Lim CH; Yang H; Ryan MD; Musgrave CB; Miyake GM Organocatalyzed atom transfer radical polymerization driven by visible light. Science 2016, 352, 1082–1086. - PubMed
- Pearson RM; Lim CH; McCarthy BG; Musgrave CB; Miyake GM Organocatalyzed Atom Transfer Radical Polymerization Using N-Aryl Phenoxazines as Photoredox Catalysts. J. Am. Chem. Soc 2016, 138, 11399–11407. - PMC - PubMed
- Pan XC; Lamson M; Yan JJ; Matyjaszewski K Photo-Induced Metal-Free Atom Transfer Radical Polymerization of Acrylonitrile. ACS Macro Lett. 2015, 4, 192–196. - PubMed
- Dadashi-Silab S; Pan XC; Matyjaszewski K Phenyl benzo[b]phenothiazine as a visible light photoredox catalyst for metal-free atom transfer radical polymerization. Chem. - Eur. J 2017, 23, 5972–5977. - PubMed
- Ryan MD; Theriot JC; Lim CH; Yang HS; Lockwood AG; Garrison NG; Lincoln SR; Musgrave CB; Miyake GM Solvent effects on the intramolecular charge transfer character of N,N-diaryl dihydrophenazine catalysts for organocatalyzed atom transfer radical polymerization. J. Polym. Sci., Part A: Polym. Chem 2017, 55, 3017–3027. - PMC - PubMed
- Singh VK; Yu C; Badgujar S; Kim Y; Kwon Y; Kim D; Lee J; Akhter T; Thangavel G; Park LS; Lee J; Nandajan PC; Wannemacher R; Milian-Medina B; Luer L; Kim KS; Gierschner J; Kwon MS Highly efficient organic photocatalysts discovered via a computer-aided-design strategy for visible-light-driven atom transfer radical polymerization. Nat. Catal 2018, 1, 794–804.
- McCarthy BG; Pearson RM; Lim CH; Sartor SM; Damrauer NH; Miyake GM Structure-Property Relationships for Tailoring Phenoxazines as Reducing Photoredox Catalysts. J. Am. Chem. Soc 2018, 140, 5088–5101. - PMC - PubMed
- Cole JP; Federico CR; Lim CH; Miyake GM Photoinduced Organocatalyzed Atom Transfer Radical Polymerization Using Low ppm Catalyst Loading. Macromolecules 2019, 52, 747–754. - PMC - PubMed
- Buss BL; Lim CH; Miyake GM Dimethyl-dihydroacridines as Photocatalysts in the Organocatalyzed Atom Transfer Radical Polymerization of Acrylate Monomers. Angew. Chem., Int. Ed 2020, 59, 3209. - PMC - PubMed
- Kutahya C; Allushi A; Isci R; Kreutzer J; Ozturk T; Yilmaz G; Yagci Y Photoinduced Metal-Free Atom Transfer Radical Polymerization Using Highly Conjugated Thienothiophene Derivatives. Macromolecules 2017, 50, 6903–6910.
- Sartor SM; Lattke YM; McCarthy BG; Miyake GM; Damrauer NH Effects of Naphthyl Connectivity on the Photo-physics of Compact Organic Charge-Transfer Photoredox Catalysts. J. Phys. Chem. A 2019, 123, 4727–4736. - PMC - PubMed
- Koyama D; Dale HJA; Orr-Ewing AJ Ultrafast Observation of a Photoredox Reaction Mechanism: Photoinitiation in Organocatalyzed Atom-Transfer Radical Polymerization. J. Am. Chem. Soc 2018, 140, 1285–1293. - PubMed
- Jockusch S; Yagci Y The active role of excited states of phenothiazines in photoinduced metal free atom transfer radical polymerization: singlet or triplet excited states? Polym. Chem 2016, 7, 6039–6043.
- Sartor SM; McCarthy BG; Pearson RM; Miyake GM; Damrauer NH Exploiting Charge-Transfer States for Maximizing Intersystem Crossing Yields in Organic Photoredox Catalysts. J. Am. Chem. Soc 2018, 140, 4778–4781. - PMC - PubMed
Grants and funding
LinkOut - more resources
Full Text Sources
Other Literature Sources