Significant 13C NMR signal enhancements in amino acids via adiabatic demagnetization and remagnetization cross polarization

Abstract

Herein, we report an improvement over Hartmann–Hahn cross polarization for NMR signal enhancement: adiabatic demagnetization/remagnetization transfers that provide up to a 9-fold experimental speedup for ¹³C NMR signals in amino acids over conventional means. The experiment proved insensitive to site type, and we also demonstrate a means for making it compatible with high-resolution spectroscopy.