Dynamic Nuclear Polarization NMR of Low-γ Nuclei: Structural Insights into Hydrated Yttrium-Doped BaZrO3

J Phys Chem Lett. 2014 Jul 17;5(14):2431-6. doi: 10.1021/jz5007669. Epub 2014 Jun 30.

Abstract

We demonstrate that solid-state NMR spectra of challenging nuclei with a low gyromagnetic ratio such as yttrium-89 can be acquired quickly with indirect dynamic nuclear polarization (DNP) methods. Proton to (89)Y cross polarization (CP) magic angle spinning (MAS) spectra of Y(3+) in a frozen aqueous solution were acquired in minutes using the AMUPol biradical as a polarizing agent. Subsequently, the detection of the (89)Y and (1)H NMR signals from technologically important hydrated yttrium-doped zirconate ceramics, in combination with DFT calculations, allows the local yttrium and proton environments present in these protonic conductors to be detected and assigned to different hydrogen-bonded environments.

Keywords: dynamic nuclear polarization; hydrated yttrium-doped barium zirconate; solid-state nuclear magnetic resonance; yttrium-89.