Standard

Origin of Long-Range Hyperfine Couplings in the EPR Spectra of 2,2,5,5-Tetraethylpyrrolidine-1-oxyls. / Polienko, Yuliya F; Dobrynin, Sergey A; Lomanovich, Konstantin A и др.

в: ACS Omega, Том 8, № 41, 17.10.2023, стр. 38723-38732.

Результаты исследований: Научные публикации в периодических изданияхстатьяРецензирование

Harvard

Polienko, YF, Dobrynin, SA, Lomanovich, KA, Brovko, AO, Bagryanskaya, EG & Kirilyuk, IA 2023, 'Origin of Long-Range Hyperfine Couplings in the EPR Spectra of 2,2,5,5-Tetraethylpyrrolidine-1-oxyls', ACS Omega, Том. 8, № 41, стр. 38723-38732. https://doi.org/10.1021/acsomega.3c06090

APA

Polienko, Y. F., Dobrynin, S. A., Lomanovich, K. A., Brovko, A. O., Bagryanskaya, E. G., & Kirilyuk, I. A. (2023). Origin of Long-Range Hyperfine Couplings in the EPR Spectra of 2,2,5,5-Tetraethylpyrrolidine-1-oxyls. ACS Omega, 8(41), 38723-38732. https://doi.org/10.1021/acsomega.3c06090

Vancouver

Polienko YF, Dobrynin SA, Lomanovich KA, Brovko AO, Bagryanskaya EG, Kirilyuk IA. Origin of Long-Range Hyperfine Couplings in the EPR Spectra of 2,2,5,5-Tetraethylpyrrolidine-1-oxyls. ACS Omega. 2023 окт. 17;8(41):38723-38732. doi: 10.1021/acsomega.3c06090

Author

Polienko, Yuliya F ; Dobrynin, Sergey A ; Lomanovich, Konstantin A и др. / Origin of Long-Range Hyperfine Couplings in the EPR Spectra of 2,2,5,5-Tetraethylpyrrolidine-1-oxyls. в: ACS Omega. 2023 ; Том 8, № 41. стр. 38723-38732.

BibTeX

@article{abe2d37796ac42f896efacf5989a1d77,
title = "Origin of Long-Range Hyperfine Couplings in the EPR Spectra of 2,2,5,5-Tetraethylpyrrolidine-1-oxyls",
abstract = "Cyclic nitroxides with several bulky alkyl substituents adjacent to the nitroxide group are known to demonstrate a much higher stability to bioreduction than their tetramethyl analogues. Among these so-called {"}sterically shielded{"} nitroxides, the pyrrolidine derivatives are the most stable. The EPR spectra of some sterically shielded pyrrolidine-1-oxyls were reported to show one or two large additional doublet splittings with a hyperfine coupling (hfc) constant (ca. 0.2-0.4 mT). To determine the origin of these hfc, a series of 2-R-2,5,5-triethyl-3,4-bis(hydroxymethyl)-pyrrolidine-1-oxyls with methylene groups stereospecifically enriched with deuterium were prepared, and their CW EPR spectra were studied. In addition, these nitroxides were investigated using quantum chemical calculations on the UB3LYP/def2-TZVP level and NBO analysis. The apparent constants were assigned to hfc with γ-hydrogen in the side chain, with the contribution of the NBO orbital βπ*(N-O) to the natural localized molecular orbital βσ(C-H) playing the major role. This interaction is efficient if the ethyl substituent is in the pseudoaxial position of the ring and the CH2-CH3 bond is codirected with (parallel to) N-O. The apparent constant aH increases with the Boltzmann population of this conformation.",
author = "Polienko, {Yuliya F} and Dobrynin, {Sergey A} and Lomanovich, {Konstantin A} and Brovko, {Anastasiya O} and Bagryanskaya, {Elena G} and Kirilyuk, {Igor A}",
note = "This work was supported by the Russian Science Foundation (grant number 22-73-00098). We thank the Multi-Access Chemical Research Center SB RAS for spectral and analytical measurements. {\textcopyright} 2023 The Authors. Published by American Chemical Society.",
year = "2023",
month = oct,
day = "17",
doi = "10.1021/acsomega.3c06090",
language = "English",
volume = "8",
pages = "38723--38732",
journal = "ACS Omega",
issn = "2470-1343",
publisher = "American Chemical Society",
number = "41",

}

RIS

TY - JOUR

T1 - Origin of Long-Range Hyperfine Couplings in the EPR Spectra of 2,2,5,5-Tetraethylpyrrolidine-1-oxyls

AU - Polienko, Yuliya F

AU - Dobrynin, Sergey A

AU - Lomanovich, Konstantin A

AU - Brovko, Anastasiya O

AU - Bagryanskaya, Elena G

AU - Kirilyuk, Igor A

N1 - This work was supported by the Russian Science Foundation (grant number 22-73-00098). We thank the Multi-Access Chemical Research Center SB RAS for spectral and analytical measurements. © 2023 The Authors. Published by American Chemical Society.

PY - 2023/10/17

Y1 - 2023/10/17

N2 - Cyclic nitroxides with several bulky alkyl substituents adjacent to the nitroxide group are known to demonstrate a much higher stability to bioreduction than their tetramethyl analogues. Among these so-called "sterically shielded" nitroxides, the pyrrolidine derivatives are the most stable. The EPR spectra of some sterically shielded pyrrolidine-1-oxyls were reported to show one or two large additional doublet splittings with a hyperfine coupling (hfc) constant (ca. 0.2-0.4 mT). To determine the origin of these hfc, a series of 2-R-2,5,5-triethyl-3,4-bis(hydroxymethyl)-pyrrolidine-1-oxyls with methylene groups stereospecifically enriched with deuterium were prepared, and their CW EPR spectra were studied. In addition, these nitroxides were investigated using quantum chemical calculations on the UB3LYP/def2-TZVP level and NBO analysis. The apparent constants were assigned to hfc with γ-hydrogen in the side chain, with the contribution of the NBO orbital βπ*(N-O) to the natural localized molecular orbital βσ(C-H) playing the major role. This interaction is efficient if the ethyl substituent is in the pseudoaxial position of the ring and the CH2-CH3 bond is codirected with (parallel to) N-O. The apparent constant aH increases with the Boltzmann population of this conformation.

AB - Cyclic nitroxides with several bulky alkyl substituents adjacent to the nitroxide group are known to demonstrate a much higher stability to bioreduction than their tetramethyl analogues. Among these so-called "sterically shielded" nitroxides, the pyrrolidine derivatives are the most stable. The EPR spectra of some sterically shielded pyrrolidine-1-oxyls were reported to show one or two large additional doublet splittings with a hyperfine coupling (hfc) constant (ca. 0.2-0.4 mT). To determine the origin of these hfc, a series of 2-R-2,5,5-triethyl-3,4-bis(hydroxymethyl)-pyrrolidine-1-oxyls with methylene groups stereospecifically enriched with deuterium were prepared, and their CW EPR spectra were studied. In addition, these nitroxides were investigated using quantum chemical calculations on the UB3LYP/def2-TZVP level and NBO analysis. The apparent constants were assigned to hfc with γ-hydrogen in the side chain, with the contribution of the NBO orbital βπ*(N-O) to the natural localized molecular orbital βσ(C-H) playing the major role. This interaction is efficient if the ethyl substituent is in the pseudoaxial position of the ring and the CH2-CH3 bond is codirected with (parallel to) N-O. The apparent constant aH increases with the Boltzmann population of this conformation.

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85176150487&origin=inward&txGid=1036fe146f9b9f6d712fc0e59515bec4

U2 - 10.1021/acsomega.3c06090

DO - 10.1021/acsomega.3c06090

M3 - Article

C2 - 37867656

VL - 8

SP - 38723

EP - 38732

JO - ACS Omega

JF - ACS Omega

SN - 2470-1343

IS - 41

ER -

ID: 56486187