Microwave-gated dynamic nuclear polarization

Aurélien Bornet (1) , Arthur Pinon (1) , Aditya Jhajharia (2, 3) , Mathieu Baudin (1, 2, 3) , Xiao Ji (1, 2, 3) , Lyndon Emsley (1) , Geoffrey Bodenhausen (2, 3) , Jan Henrik Ardenkjaer-Larsend (4, 5) , Sami Jannin (1, 6, 7)

1 EPFL - Ecole Polytechnique Fédérale de Lausanne
2 UPMC - Université Pierre et Marie Curie - Paris 6
3 PSL - Université Paris Sciences et Lettres
4 DTU Electrical Engineering [Lyngby]
5 GE Healthcare
6 ISA - Hyperpolarized Magnetic Resonance
7 Bruker BioSpin

Dissolution dynamic nuclear polarization (D-DNP) has become a method of choice to enhance signals in nuclear magnetic resonance (NMR). Recently, we have proposed to combine cross-polarization (CP) with D-DNP to provide high polarization P(13C) in short build-up times. In this paper, we show that switching microwave irradiation off for a few hundreds of milliseconds prior to CP can significantly boost the efficiency. By implementing microwave gating, 13C polarizations on sodium [1-13C]acetate as high as 64% could be achieved with a polarization build-up time constant as short as 160 s. A polarization of P(13C) = 78% could even be reached for [13C]urea.

Domaines: Chimie analytique

Aurélien Bornet, Arthur Pinon, Aditya Jhajharia, Mathieu Baudin, Xiao Ji, et al.. Microwave-gated dynamic nuclear polarization . Physical Chemistry Chemical Physics, 2016, 18 (44), pp.30530-30535 ⟨10.1039/C6CP05587G⟩. ⟨hal-01405900⟩