Application of a high-resolution superconducting NMR probe in natural product structure determination†

The r.f. properties of a high-resolution NMR probehead constructed of epitaxial thin films of high-temperature superconducting ceramics are presented. Operating the probe transmit/receive elements at 25 K significantly decreases the thermal noise of the r.f. coils and increases the probe quality factor (Q), resulting in a substantial increase in the signal-to-noise ratio. The lineshape and r.f. transmission characteristics of this probe were investigated. The utility of this probe for natural product structure determination was demonstrated using selective 1D NOE difference spectra.