Solid-state dynamic nuclear polarization at 263 GHz: spectrometer design and experimental results

被引：310

作者：

Rosay, Melanie ^{[1
]}

Tometich, Leo ^{[1
]}

Pawsey, Shane ^{[1
]}

Bader, Reto ^{[2
]}

Schauwecker, Robert ^{[2
]}

Blank, Monica ^{[3
]}

Borchard, Philipp M. ^{[3
]}

Cauffman, Stephen R. ^{[3
]}

Felch, Kevin L. ^{[3
]}

Weber, Ralph T. ^{[1
]}

Temkin, Richard J. ^{[4
]}

Griffin, Robert G. ^{[4
]}

Maas, Werner E. ^{[1
]}

机构：

[1] Bruker BioSpin Corp, Billerica, MA 01821 USA

[2] Bruker BioSpin Corp, CH-8117 Fallanden, Switzerland

[3] Commun & Power Ind, Palo Alto, CA 94303 USA

[4] MIT, Cambridge, MA 02139 USA

来源：

PHYSICAL CHEMISTRY CHEMICAL PHYSICS | 2010年 / 12卷 / 22期

关键词：

ANGLE-SPINNING NMR; ENHANCED NMR; C-13; NMR; GYROTRON; DNP; SPECTROSCOPY; RESONANCE; INTERFACE; PEPTIDE; MODEL;

D O I：

10.1039/c003685b

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Dynamic Nuclear Polarization (DNP) experiments transfer polarization from electron spins to nuclear spins with microwave irradiation of the electron spins for enhanced sensitivity in nuclear magnetic resonance (NMR) spectroscopy. Design and testing of a spectrometer for magic angle spinning (MAS) DNP experiments at 263 GHz microwave frequency, 400 MHz H-1 frequency is described. Microwaves are generated by a novel continuous-wave gyrotron, transmitted to the NMR probe via a transmission line, and irradiated on a 3.2 mm rotor for MAS DNP experiments. DNP signal enhancements of up to 80 have been measured at 95 K on urea and proline in water-glycerol with the biradical polarizing agent TOTAPOL. We characterize the experimental parameters affecting the DNP efficiency: the magnetic field dependence, temperature dependence and polarization build-up times, microwave power dependence, sample heating effects, and spinning frequency dependence of the DNP signal enhancement. Stable system operation, including DNP performance, is also demonstrated over a 36 h period.

引用

页码：5850 / 5860

页数：11

共 65 条

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