Dendritic polarizing agents for DNP SENS.

Dendritic polarizing agents for DNP SENS† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c6sc03139k Click here for additional data file.

Effects of biradical deuteration on the performance of DNP: towards better performing polarizing agents.

We study the effects of the deuteration of biradical polarizing agents on the efficiency of dynamic nuclear polarization (DNP) via the cross-effect. To this end, we synthesized a series of bTbK and TOTAPol biradicals with systematically increased deuterium substitution. The deuteration increases the radicals' relaxation time, thus contributing to a higher saturation factor and larger DNP enhanc...

Theory of solid effect and cross effect dynamic nuclear polarization with half-integer high-spin metal polarizing agents in rotating solids.

Dynamic nuclear polarization (DNP) is a powerful method to enhance sensitivity especially of solid-state magic-angle spinning (MAS) NMR by up to several orders of magnitude. The increased interest both from a practical as well as theoretical viewpoint has spawned several fields of active research such as the development of new polarizing agents with improved or unique properties and description...

Dynamic Nuclear Polarization of [superscript 17] O: Direct Polarization

Dynamic nuclear polarization of 17O was studied using four different polarizing agents – the biradical TOTAPOL, and the monoradicals trityl and SA-BDPA, as well as a mixture of the latter two. Field profiles, DNP mechanisms and enhancements were measured to better understand and optimize directly polarizing this low-gamma quadrupolar nucleus using both monoand bi-radical polarizing agents. Enha...

Efficient cross-effect dynamic nuclear polarization without depolarization in high-resolution MAS NMR.

Dynamic nuclear polarization (DNP) has the potential to enhance the sensitivity of magic-angle spinning (MAS) NMR by many orders of magnitude and therefore to revolutionize atomic resolution structural analysis. Currently, the most widely used approach to DNP for studies of chemical, material, and biological systems involves the cross-effect (CE) mechanism, which relies on biradicals as polariz...