Long-range proton hyperfine coupling in alicyclic nitroxide radicals by electron paramagnetic resonance

1984 ◽  
Vol 88 (20) ◽  
pp. 4717-4723 ◽  
Author(s):  
Magdi M. Mossoba ◽  
Keisuke Makino ◽  
Peter Riesz ◽  
Ray C. Perkins
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Long Range ◽  
Hyperfine Coupling ◽  
Nitroxide Radicals ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic

Electron Paramagnetic Resonance as a Probe of Conformational Flexibility in Cyclic Alkanes

1980 ◽  
Vol 34 (3) ◽  
pp. 268-275 ◽  
Author(s):  
Marsha J. Heinig ◽  
G. R. Eaton ◽  
S. S. Eaton
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Long Range ◽  
Hyperfine Coupling ◽  
Nitroxyl Radical ◽  
Nitroxyl Radicals ◽  
Epr Spectra ◽  
Paramagnetic Resonance ◽  
Cyclic Alkanes ◽  
Temperature Spectra ◽  
Electron Paramagnetic

Electron paramagnetic resonance (EPR) spectra of a homologous series of nitroxyl radicals derived from cyclic alkanones with 6 to 15 carbons in the ring have been obtained as a function of temperature. Long-range hyperfine coupling (0.7 to 2.2 G) was observed in the low-temperature spectra for rings with 6, 7, and 9 to 15 carbons. Deuteration of the 11- to 14-membered rings indicated that the long-range coupling was to one of the protons on the carbons adjacent to the point of attachment of the nitroxyl radical. For the 9- to 15-membered rings, there was a temperature region in which the hyperfine coupling decreased rapidly. This decrease is attributed to rapid conformational averaging on the EPR time scale. For the 12-, 13-, and 15-membered rings, the high temperature spectra exhibited resolved hyperfine coupling which can be computer-simulated, assuming four equivalent protons. The activation energies estimated from the coalescence temperatures in the EPR spectra fall in the range estimated by nuclear magnetic resonance and show similar influences of ring size on rigidity.

scholarly journals Triarylmethyl Radicals: An EPR Study of 13C Hyperfine Coupling Constants

2017 ◽  
Vol 231 (4) ◽  
Author(s):  
Andrey A. Kuzhelev ◽  
Victor M. Tormyshev ◽  
Olga Yu. Rogozhnikova ◽  
Dmitry V. Trukhin ◽  
Tatiana I. Troitskaya ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Epr Spectroscopy ◽  
Hyperfine Coupling ◽  
Coupling Constants ◽  
Spin Labels ◽  
Spin Probes ◽  
Paramagnetic Resonance ◽  
Hyperfine Coupling Constants ◽  
Electron Paramagnetic ◽  
Triarylmethyl Radicals

AbstractTriarylmethyl (TAM) radicals are widely used in electron paramagnetic resonance (EPR) spectroscopy as spin labels and in EPR imaging as spin probes for

scholarly journals Direct enantiomeric discrimination through antisymmetric hyperfine coupling

2021 ◽  
Author(s):  
Piotr Garbacz ◽  
Juha Vaara
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Hyperfine Coupling ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Resonance Spectroscopy ◽  
Paramagnetic Resonance ◽  
Molecular Chirality ◽  
Enantiomeric Discrimination ◽  
Electron Paramagnetic

A chirality-sensitive effect induced by antisymmetric hyperfine coupling, which lifts the intrinsic insensitivity of electron paramagnetic resonance spectroscopy to molecular chirality, is described.

Sign in / Sign up

Export Citation Format

Share Document