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DFT studies on one-electron oxidation and one-electron reduction for 2- and 4-aminopyridines

Quantum-chemical calculations {DFT(B3LYP)/6-311+G(d,p)} were performed for all possible tautomers (aromatic and nonaromatic) of neutral 2- and 4-aminopyridines and their oxidized and reduced forms. One-electron oxidation has no important effect on the tautomeric preference for 2-aminopyridine. The a...

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Autores principales: Raczyńska, Ewa D., Stępniewski, Tomasz M., Kolczyńska, Katarzyna
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Springer-Verlag 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3429776/
https://www.ncbi.nlm.nih.gov/pubmed/22585356
http://dx.doi.org/10.1007/s00894-012-1446-8
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author Raczyńska, Ewa D.
Stępniewski, Tomasz M.
Kolczyńska, Katarzyna
author_facet Raczyńska, Ewa D.
Stępniewski, Tomasz M.
Kolczyńska, Katarzyna
author_sort Raczyńska, Ewa D.
collection PubMed
description Quantum-chemical calculations {DFT(B3LYP)/6-311+G(d,p)} were performed for all possible tautomers (aromatic and nonaromatic) of neutral 2- and 4-aminopyridines and their oxidized and reduced forms. One-electron oxidation has no important effect on the tautomeric preference for 2-aminopyridine. The amine tautomer is favored. However, oxidation increases the stability of the imine NH tautomer, and its contribution in the tautomeric mixture cannot be neglected. In the case of 4-aminopyridine, one-electron oxidation increases the stability of both the amine and imine NH tautomers. Consequently, they possess very close energies. As major tautomers, they dictate the composition of the tautomeric mixture. The CH tautomers may be considered as very rare forms for both neutral and oxidized aminopyridines. A reverse situation takes place for the reduced forms of aminopyridines. One-electron reduction favors the C3 atom for the labile proton for both aminopyridines. This may partially explain the origin of the CH tautomers for the anionic states of nucleobases containing the exo NH(2) group.
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spelling pubmed-34297762012-09-04 DFT studies on one-electron oxidation and one-electron reduction for 2- and 4-aminopyridines Raczyńska, Ewa D. Stępniewski, Tomasz M. Kolczyńska, Katarzyna J Mol Model Original Paper Quantum-chemical calculations {DFT(B3LYP)/6-311+G(d,p)} were performed for all possible tautomers (aromatic and nonaromatic) of neutral 2- and 4-aminopyridines and their oxidized and reduced forms. One-electron oxidation has no important effect on the tautomeric preference for 2-aminopyridine. The amine tautomer is favored. However, oxidation increases the stability of the imine NH tautomer, and its contribution in the tautomeric mixture cannot be neglected. In the case of 4-aminopyridine, one-electron oxidation increases the stability of both the amine and imine NH tautomers. Consequently, they possess very close energies. As major tautomers, they dictate the composition of the tautomeric mixture. The CH tautomers may be considered as very rare forms for both neutral and oxidized aminopyridines. A reverse situation takes place for the reduced forms of aminopyridines. One-electron reduction favors the C3 atom for the labile proton for both aminopyridines. This may partially explain the origin of the CH tautomers for the anionic states of nucleobases containing the exo NH(2) group. Springer-Verlag 2012-05-15 2012 /pmc/articles/PMC3429776/ /pubmed/22585356 http://dx.doi.org/10.1007/s00894-012-1446-8 Text en © The Author(s) 2012 https://creativecommons.org/licenses/by/4.0/ This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.
spellingShingle Original Paper
Raczyńska, Ewa D.
Stępniewski, Tomasz M.
Kolczyńska, Katarzyna
DFT studies on one-electron oxidation and one-electron reduction for 2- and 4-aminopyridines
title DFT studies on one-electron oxidation and one-electron reduction for 2- and 4-aminopyridines
title_full DFT studies on one-electron oxidation and one-electron reduction for 2- and 4-aminopyridines
title_fullStr DFT studies on one-electron oxidation and one-electron reduction for 2- and 4-aminopyridines
title_full_unstemmed DFT studies on one-electron oxidation and one-electron reduction for 2- and 4-aminopyridines
title_short DFT studies on one-electron oxidation and one-electron reduction for 2- and 4-aminopyridines
title_sort dft studies on one-electron oxidation and one-electron reduction for 2- and 4-aminopyridines
topic Original Paper
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3429776/
https://www.ncbi.nlm.nih.gov/pubmed/22585356
http://dx.doi.org/10.1007/s00894-012-1446-8
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