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Manuscript-Han-etal.pdf (7.06 MB)

Pulse Shaped Dynamic Nuclear Polarization Under Magic Angle Spinning

submitted on 09.09.2019, 19:44 and posted on 11.09.2019, 16:17 by ASIF EQUBAL, Kan Tagami, Songi Han
In this paper, we report on an entirely novel way of improving the MAS-DNP efficiency by shaped μw pulse train irradiation for fast and broad-banded (FAB) saturation of the electron spin resonance. FAB-DNP achieved with Arbitrary Wave Generated shaped μw pulse trains facilitates effective and selective saturation of a defined fraction of the total electron spins, and provides superior control over the DNP efficiency under MAS. Experimental and quantum-mechanics based numerically simulated results together demonstrate that FAB-DNP significantly outperforms CW-DNP when the EPR-line of PAs is broadened by conformational distribution and exchange coupling. We demonstrate that the maximum benefit of FAB DNP is achieved when the electron spin-lattice relaxation is fast relative to the MAS frequency, i.e. at higher temperatures and/or when employing metals as PAs. Calculations predict that under short T1e conditions AWG-DNP can achieve as much as ~4-fold greater enhancement compared to CW-DNP.


National Institute of Health through Grant No. R21EB022731

Binational Science Foundation through Grant No. 2014149


Email Address of Submitting Author


University of California Santa Barbara


United States of America

ORCID For Submitting Author


Declaration of Conflict of Interest

No conflict of interest

Version Notes

Version 1.0


Read the published paper

in The Journal of Physical Chemistry Letters