Реферат: Recent advances in NMR and MRI have been driven by the development of hyperpolarization techniques that overcome intrinsic sensitivity limitations. Signal Amplification by Reversible Exchange (SABRE), a parahydrogen-based method relying on the reversible binding of substrates to the iridium complexes, has emerged as a versatile approach for enhancing nuclear spin polarization, most commonly for 1H, 13C, and 15N nuclei. Here, we extend the scope of SABRE to 77Se. Using a selenium–nitrogen heterocycle, we investigate the mechanisms of 77Se hyperpolarization. Direct polarization transfer from parahydrogen-derived hydrides to 77Se proves inefficient; instead, hyperpolarization is achieved via a 15N spin relay, enabling polarization levels exceeding 5%. This relay mechanism operates effectively at microtesla magnetic fields, even at natural isotopic abundance (0.028% of 15N–77Se pairs), where spontaneous polarization transfer to both 15N and 77Se is governed by matching conditions tuned by the external magnetic field. Extending beyond microtesla fields to the more convenient Earth’s-field range (50–100 μT), we employ resonant audio-frequency RF pulse sequences to actively control the 15N spin relay, enabling highly selective polarization of 15N and 77Se spins without magnetic shielding. Demonstrating the broader utility of this approach, we apply the audio-frequency pulsing strategy to directly observe 13C correlations in 15N NMR spectra, highlighting its potential for probing heteronuclear networks beyond 15N–77Se. These results establish 15N-mediated polarization transfer as a powerful and versatile strategy for 77Se hyperpolarization and open new opportunities for extending SABRE to biologically relevant selenium-containing compounds.

Библиографическая ссылка: Markelov D. , Kiryutin A. , Godovikov I. , Sheberstov K. , Yurkovskaya A.
Coherent Control of 15N Spin Relay in SABRE Enables over 5% 77Se Polarization
В сборнике Book of poster abstracts of Euromar 2026. 2026. – C.156.

Даты:

Поступила в редакцию:	17 мая 2026 г.
Опубликована online:	1 июн. 2026 г.

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