Design and implementation of a J-coupled spectrometer for multidimensional structure and relaxation detection at low magnetic fields.

摘要: In recent years, it has been realized that low and ultra-low field (mT-nT magnetic range) nuclear resonance spectroscopy can be used for molecular structural analysis. However, spectra are often hindered by lengthy acquisition times or require large sample volumes high concentrations. Here, we report a (50 μT) instrument employs linear actuator to shuttle samples between 1 T prepolarization solenoid detector in laboratory setting. The current experimental setup is benchmarked using water 13C-methanol with single scan detection limit of 2 × 1020 spins (3 µl, 55M H2O) 2.9 1019 (200 617 mM 13C-methanol) signal averaging. system dynamic range >3 orders magnitude. Investigations room-temperature relaxation dynamics show dilution lieu heating acquire linewidths comparable high-temperature spectra. These results indicate the T1 T2 mechanisms governed both proton exchange rate dissolved oxygen sample. Finally, 2D correlation experiment reported, performed strong coupling regime resolves multiple resonances associated heteronuclear J-coupling. spectrum was collected 10 less than half time from previous reports limit.