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Title: J -Driven dynamic nuclear polarization for sensitizing high field solution state NMR
Dynamic nuclear polarization (DNP) is widely used to enhance solid state nuclear magnetic resonance (NMR) sensitivity. Its efficiency as a generic signal-enhancing approach for liquid state NMR, however, decays rapidly with magnetic field B 0 , unless mediated by scalar interactions arising only in exceptional cases. This has prevented a more widespread use of DNP in structural and dynamical solution NMR analyses. This study introduces a potential solution to this problem, relying on biradicals with exchange couplings J ex of the order of the electron Larmor frequency ω E . Numerical and analytical calculations show that in such J ex ≈ ± ω E cases a phenomenon akin to that occurring in chemically induced DNP (CIDNP) happens, leading to different relaxation rates for the biradical singlet and triplet states which are hyperfine-coupled to the nuclear α or β states. Microwave irradiation can then generate a transient nuclear polarization build-up with high efficiency, at all magnetic fields that are relevant in contemporary NMR, and for all rotational diffusion correlation times that occur in small- and medium-sized molecules in conventional solvents.  more » « less
Award ID(s):
1808660
NSF-PAR ID:
10349895
Author(s) / Creator(s):
; ;
Date Published:
Journal Name:
Physical Chemistry Chemical Physics
Volume:
24
Issue:
4
ISSN:
1463-9076
Page Range / eLocation ID:
2118 to 2125
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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