title: Effects of biradical deuteration on the performance of DNP: towards better performing polarizing agents.
abstract: 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 enhancement, and reduces the pool of protons within the so-called spin diffusion barrier. Notably, we report that full or partial deuteration leads to improved DNP enhancement factors in standard samples, but also slows down the build-up of hyperpolarization. Improvements in DNP enhancements factors of up to 70% and time savings of up to 38% are obtained upon full deuteration. It is foreseen that this approach may be applied to other DNP polarizing agents thus enabling further sensitivity improvements.
authors.affiliation: U.S. DOE Ames Laboratory, Iowa State University, 230 Spedding Hall, Ames, IA 50011-3020, USA. mpruski@iastate.edu.
authors.forename: Frédéric A
authors.initials: FA
authors.lastname: Perras
authors.forename: Regina R
authors.initials: RR
authors.lastname: Reinig
authors.forename: Igor I
authors.initials: II
authors.lastname: Slowing
authors.forename: Aaron D
authors.initials: AD
authors.lastname: Sadow
authors.forename: Marek
authors.initials: M
authors.lastname: Pruski