Chemistry Reference
In-Depth Information
Dynamic Nuclear Polarization: New
Methodology and Applications
Kong Hung Sze, Qinglin Wu, Ho Sum Tse, and Guang Zhu
Abstract One way to overcome the intrinsically low sensitivity of Nuclear Mag-
netic Resonance spectroscopy is to enhance the signal by dynamic nuclear polari-
zation (DNP), where the polarization of high-gyromagnetic ratio (
) electrons is
transferred to the surrounding nuclei using microwave (MW) irradiation. Recent
developments in DNP instrumentations and applications have shown that DNP is
one of the most effective methods to increase the nuclear spin polarization in
inorganic, organic, and biological materials. It is possible to obtain a solution of
molecules containing hyperpolarized nuclei in combination with methods to dis-
solve rapidly the polarized solid sample. In this chapter, a brief introduction on a
theoretical basis and some of new DNP applications in NMR spectroscopy as well
as medical applications in Magnetic Resonance Imaging (MRI) are described.
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Keywords DNP
NMR
MRIh
Contents
1 Introduction .................................................................................. 216
2 Theories of Dynamic Nuclear Polarization ................................................ 217
2.1 Continuous-Wave DNP Mechanism .................................................. 218
2.2 Pulsed DNP ............................................................................ 221
2.3 Polarizing Agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224
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