NMR and EPR Study of Homolysis of Diastereomeric Alkoxyamines
Three alkoxyamines based on imidazoline radicals with a pyridine functional group—potential initiators of nitroxide-mediated, controlled radical polymerization—were synthesized. Electron Paramagnetic Resonance (EPR) measurements reveal biexponential kinetics for the thermolysis for diastereomeric al...
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MDPI AG
2020-11-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/25/21/5080 |
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| author | Sergey Cherkasov Dmitriy Parkhomenko Alexander Genaev Georgii Salnikov Mariya Edeleva Denis Morozov Tatyana Rybalova Igor Kirilyuk Sylvain R. A. Marque Elena Bagryanskaya |
| author_facet | Sergey Cherkasov Dmitriy Parkhomenko Alexander Genaev Georgii Salnikov Mariya Edeleva Denis Morozov Tatyana Rybalova Igor Kirilyuk Sylvain R. A. Marque Elena Bagryanskaya |
| author_sort | Sergey Cherkasov |
| collection | DOAJ |
| description | Three alkoxyamines based on imidazoline radicals with a pyridine functional group—potential initiators of nitroxide-mediated, controlled radical polymerization—were synthesized. Electron Paramagnetic Resonance (EPR) measurements reveal biexponential kinetics for the thermolysis for diastereomeric alkoxyamines and monoexponential kinetics for an achiral alkoxyamine. For comparison, the thermolysis of all three alkoxyamines was studied by NMR in the presence of three different scavengers, namely tetramethylpiperidine-N-oxyl (TEMPO), thiophenol (PhSH), and β-mercaptoethanol (BME), and detailed analysis of products was performed. NMR differentiates between <i>N</i>-inversion, epimerization, and homolysis reactions. The choice of scavenger is crucial for making a reliable and accurate estimate of the true homolysis rate constant. |
| first_indexed | 2024-03-10T15:08:52Z |
| format | Article |
| id | doaj.art-3fad057cc0a944e7aef863978ed29343 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-10T15:08:52Z |
| publishDate | 2020-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-3fad057cc0a944e7aef863978ed293432023-11-20T19:27:44ZengMDPI AGMolecules1420-30492020-11-012521508010.3390/molecules25215080NMR and EPR Study of Homolysis of Diastereomeric AlkoxyaminesSergey Cherkasov0Dmitriy Parkhomenko1Alexander Genaev2Georgii Salnikov3Mariya Edeleva4Denis Morozov5Tatyana Rybalova6Igor Kirilyuk7Sylvain R. A. Marque8Elena Bagryanskaya9N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Pr. Lavrentjeva 9, 630090 Novosibirsk, RussiaN. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Pr. Lavrentjeva 9, 630090 Novosibirsk, RussiaN. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Pr. Lavrentjeva 9, 630090 Novosibirsk, RussiaN. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Pr. Lavrentjeva 9, 630090 Novosibirsk, RussiaN. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Pr. Lavrentjeva 9, 630090 Novosibirsk, RussiaN. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Pr. Lavrentjeva 9, 630090 Novosibirsk, RussiaN. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Pr. Lavrentjeva 9, 630090 Novosibirsk, RussiaN. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Pr. Lavrentjeva 9, 630090 Novosibirsk, RussiaAix Marseille Univ, CNRS, ICR, UMR 7273, case 551, Avenue Escadrille Normandie-Niemen, 13397 Marseille CEDEX 20, FranceN. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Pr. Lavrentjeva 9, 630090 Novosibirsk, RussiaThree alkoxyamines based on imidazoline radicals with a pyridine functional group—potential initiators of nitroxide-mediated, controlled radical polymerization—were synthesized. Electron Paramagnetic Resonance (EPR) measurements reveal biexponential kinetics for the thermolysis for diastereomeric alkoxyamines and monoexponential kinetics for an achiral alkoxyamine. For comparison, the thermolysis of all three alkoxyamines was studied by NMR in the presence of three different scavengers, namely tetramethylpiperidine-N-oxyl (TEMPO), thiophenol (PhSH), and β-mercaptoethanol (BME), and detailed analysis of products was performed. NMR differentiates between <i>N</i>-inversion, epimerization, and homolysis reactions. The choice of scavenger is crucial for making a reliable and accurate estimate of the true homolysis rate constant.https://www.mdpi.com/1420-3049/25/21/5080nitroxidealkoxyaminenitroxide mediated polymerizationkineticsscavengerimidazoline radical |
| spellingShingle | Sergey Cherkasov Dmitriy Parkhomenko Alexander Genaev Georgii Salnikov Mariya Edeleva Denis Morozov Tatyana Rybalova Igor Kirilyuk Sylvain R. A. Marque Elena Bagryanskaya NMR and EPR Study of Homolysis of Diastereomeric Alkoxyamines Molecules nitroxide alkoxyamine nitroxide mediated polymerization kinetics scavenger imidazoline radical |
| title | NMR and EPR Study of Homolysis of Diastereomeric Alkoxyamines |
| title_full | NMR and EPR Study of Homolysis of Diastereomeric Alkoxyamines |
| title_fullStr | NMR and EPR Study of Homolysis of Diastereomeric Alkoxyamines |
| title_full_unstemmed | NMR and EPR Study of Homolysis of Diastereomeric Alkoxyamines |
| title_short | NMR and EPR Study of Homolysis of Diastereomeric Alkoxyamines |
| title_sort | nmr and epr study of homolysis of diastereomeric alkoxyamines |
| topic | nitroxide alkoxyamine nitroxide mediated polymerization kinetics scavenger imidazoline radical |
| url | https://www.mdpi.com/1420-3049/25/21/5080 |
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