A high saturation factor in Overhauser DNP with nitroxide derivatives: the role of (14)N nuclear spin relaxation

Enkin N, Liu G, Gimenez-Lopez Mdel C, Porfyrakis K, Tkach I, Bennati M. A high saturation factor in Overhauser DNP with nitroxide derivatives: the role of (14)N nuclear spin relaxation. Phys Chem Chem Phys. 2015;17(17):11144-9.

http://www.ncbi.nlm.nih.gov/pubmed/25855020

Overhauser DNP enhancements of toluene were measured at a magnetic field of 0.35 Tesla in a series of chemically functionalized nitroxide radicals. We observe that the enhancements increase systematically with polarizer size and rotational correlation time. Examination of the saturation factor of (14)N nitroxides by pulsed ELDOR spectroscopy led to a quantitative interpretation of the enhancements, for which the saturation factor increases up to almost unity due to enhanced nuclear ((14)N) relaxation in the nitroxide radical. The observation has a direct impact on the choice of optimum DNP polarizers in liquids.

Might this article interest your colleagues? Share it!

Have a question?

If you have questions about our instrumentation or how we can help you, please contact us.