Abstract: Triarylmethyl (TAM) radicals are widely used in electron paramagnetic resonance (EPR) spectroscopy as spin labels and in EPR imaging as spin probes for in vivo oxymetry. One of the key advantages of TAMs is the extremely narrow EPR line, especially in case of deuterated analogs (-2.5 mu T). Another advantage is their slow spin relaxation even at physiological temperatures; in particular, this characteristic enables the use of pulsed dipolar EPR methods for distance measurements in biomolecules. In this study, a large series of TAM radicals and their deuterated analogs was synthesized, and the corresponding spectroscopic parameters including C-13 hyperfine constants were determined for the first time. We observed negligible dependence of C-13 hyperfine constants on the solvent or on the structure or number of substituents at para-C atoms of the aromatic rings. In addition, we demonstrated that C-13 signals at natural abundance can be used for successful distance measurements at room temperature by pulsed electron double resonance (PELDOR or DEER).

Cite: Kuzhelev A.A. , Tormyshev V.M. , Rogozhnikova O.Y. , Trukhin D.V. , Troitskaya T.I. , Strizhakov R.K. , Krumkacheva O.A. , Fedin M.V. , Bagryanskaya E.G.
Triarylmethyl Radicals: An EPR Study of C-13 Hyperfine Coupling Constants
Zeitschrift fur Physikalische Chemie. 2017. V.231. N4. P.777-794. DOI: 10.1515/zpch-2016-0811 WOS Scopus РИНЦ

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Dates:

Published online:	Oct 5, 2016
Published print:	Jan 1, 2017

Identifiers:

Web of science	WOS:000394164200005
Scopus	2-s2.0-85012298696
Elibrary	29491959
OpenAlex	W2566759609

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