Abstract: We demonstrate a series of multitrityl radical compounds where accurate spin-counting by pulsed electron paramagnetic resonance (EPR) can be achieved at X-band (9 GHz) frequencies, even for molecules with very short and flexible linkers. Multiquantum filter experiments, well-known from NMR, were used to count the number of coupled electron spins in these compounds. The six pulse double quantum filter sequence used in EPR for distance determinations in biradicals was used. Precise phase settings to separate higher quantum coherences were achieved by an arbitrary waveform generator. The trityl radicals have narrow spectral width so that homogeneous excitation of all spins by the pulses is possible. The transversal relaxation times of higher quantum coherences of trityl radicals are sufficiently long to allow their detection. Our results on model compounds show the potential of this approach to determine oligomeric states in protein complexes in their native environment using functionalized trityl spin labels. Copyright © 2020 American Chemical Society.

Cite: Bretschneider M. , Spindler P.E. , Rogozhnikova O.Y. , Trukhin D.V. , Endeward B. , Kuzhelev A.A. , Bagryanskaya E. , Tormyshev V.M. , Prisner T.F.
Multiquantum Counting of Trityl Radicals
The Journal of Physical Chemistry Letters. 2020. V.11. N15. P.6286-6290. DOI: 10.1021/acs.jpclett.0c01615 WOS Scopus РИНЦ

Dates:

Published online:	Jul 15, 2020
Published print:	Aug 6, 2020

Identifiers:

Web of science	WOS:000562064500069
Scopus	2-s2.0-85089617423
Elibrary	45362824
OpenAlex	W3042345185

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