DNP enhanced NMR using a high-power 94 GHz microwave source: a study of the TEMPOL radical in toluene
Kryukov, Eugeny V., Newton, Mark E., Pike, Kevin J., Bolton, David R., Kowalczyk, Radoslaw M., Howes, A. P., Smith, Mark E. and Dupree, Ray. (2010) DNP enhanced NMR using a high-power 94 GHz microwave source: a study of the TEMPOL radical in toluene. Physical Chemistry Chemical Physics, Vol.12 (No.22). pp. 5757-5765. ISSN 1463-9076Full text not available from this repository.
Official URL: http://dx.doi.org/10.1039/c003189e
DNP enhanced H-1 NMR at 143 MHz in toluene is investigated using an NMR spectrometer coupled with a modified EPR spectrometer operating at 94 GHz and TEMPOL as the polarisation agent. A 100 W microwave amplifier was incorporated into the output stage of the EPR instrument so that high microwave powers could be delivered to the probe in either CW or pulsed mode. The maximum enhancement for the ring protons increases from similar to-16 for a 5 mM TEMPOL solution to similar to-50 for a 20 mM solution at a microwave power of similar to-480 mW. The temperature dependence of the enhancement, the NMR relaxation rates and the ESR spectrum of TEMPOL were also studied in an effort to obtain information on the dynamics of the system.
|Item Type:||Journal Article|
|Subjects:||Q Science > QD Chemistry
Q Science > QC Physics
|Divisions:||Faculty of Science > Physics|
|Journal or Publication Title:||Physical Chemistry Chemical Physics|
|Publisher:||Royal Society of Chemistry|
|Number of Pages:||9|
|Page Range:||pp. 5757-5765|
|Access rights to Published version:||Restricted or Subscription Access|
|Funder:||Engineering and Physical Sciences Research Council (EPSRC)|
|Grant number:||EP/D045967 (EPSRC), EP/D047730 (EPSRC)|
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