Influence of Ho$^{3+}$-doping on $^{13}$C dynamic nuclear polarization

ORAL

Abstract

We report the effects of the addition of trace Ho-DOTA on the $^{13}$C dynamic nuclear polarization and the relaxation time of [1-$^{13}$C] acetate doped with trityl OX063 free radical. Our result shows that the polarization can be improved by a factor of 2.7 fold using Ho-DOTA doping, compared to the undoped samples, similar to the effect of Gd-HP-DO3A doping. In contrast to Gd-HP-DO3A doping, the $^{13}$C relaxation rate is only minimally affected by Ho-DOTA. The W-band electron spin resonance studies revealed a considerable reduction of the electron spin-lattice relaxation time $T_1$ of trityl OX063 at low temperatures, which corresponds to the $^{13}$C polarization enhancement, in agreement with the thermodynamic picture of DNP.

*We acknowledge the support from the US Department of Defense no. W81XWH-14-1-0048 (LL) and the Robert A. Welch foundation grant no. AT-1877 (LL).

–

Authors

  • Andhika Kiswandhi

    • University of Texas at Dallas

  • Peter Niedbalski

    • University of Texas at Dallas

  • Christopher Parish

    • University of Texas at Dallas

  • Pavanjeet Kaur

    • National High Magnetic Field Laboratory

  • Andre Martins

    • University of Texas at Dallas

  • Leila Fidelino

    • University of Texas Southwestern Medical Center

  • Chalermchai Khemtong

    • University of Texas Southwestern Medical Center

  • Likai Song

    • National High Magnetic Field Laboratory

  • Alan Sherry

    • University of Texas at Dallas

  • Lloyd Lumata

    • University of Texas at Dallas