Zero to ultralow-field NMR provides chemical information in the absence of a high magnetic field but it is difficult to measure molecules with quadrupolar nuclei due to their fast relaxation. This study examines zero-field J-spectra from isotopologues of ammonium cations, with quadrupolar nuclei, revealing the presence of a primary isotope effect of −58 mHz.
- Román Picazo-Frutos
- Kirill F. Sheberstov
- Danila A. Barskiy