Abstract: Triplet states of photoexcited organic molecules are promising spin labels with advanced spectroscopic properties for pulsed dipolar electron paramagnetic resonance (PD EPR) spectroscopy. Recently proposed triplet fullerene labels have shown great potential for double electron–electron resonance (DEER) distance measurements as “observer spins” due to a high quantum yield of the triplet state, hyperpolarization and relatively narrow EPR spectra. Here, we demonstrate the applicability of fullerene labels to other PD EPR techniques, such as relaxation induced dipolar modulation enhancement (RIDME) and laser induced magnetic dipolar spectroscopy (LaserIMD). In particular, a specific contaminating signal in LaserIMD experiments was observed, explained and mitigated. Comparative analyses of the signal-to-noise (SNR) ratios were performed for all employed methods. DEER on the fullerene–triarylmethyl pair shows the best performance, which allows state-of-the-art DEER acquisition at 100 nM with a SNR of ∼35 within reasonable 42 hours.

Cite: Timofeev I.O. , Politanskaya L.V. , Tretyakov E.V. , Polienko Y.F. , Tormyshev V.M. , Bagryanskaya E.G. , Krumkacheva O.A. , Fedin M.V.
Fullerene-based triplet spin labels: methodology aspects for pulsed dipolar EPR spectroscopy
Physical Chemistry Chemical Physics. 2022. V.24. N7. P.4475-4484. DOI: 10.1039/d1cp05545c WOS Scopus OpenAlex

Identifiers:

Web of science:	WOS:000750602300001
Scopus:	2-s2.0-85124792681
OpenAlex:	W4205205205

Citing:

DB	Citing
OpenAlex	16
Scopus	9
Web of science	7

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