A nuclear magnetic resonance (NMR) method for singlet-state exchange NMR-spectroscopy comprises steps of excitation of single-quantum in-phase coherences, generation of single-quantum anti-phase coherences, excitation of zero-quantum coherences ZQx and/or longitudinal two-spin order 2IzSz (='ZZ order') using a pi/4 pulse, reversal of the sign of the zero-quantum coherences ZQx under the effect of the difference of the chemical shifts of the examined spins, transformation of the zero-quantum coherences ZQx and/or longitudinal two-spin ZZ order into singlet-state populations by means of RF irradiation during a mixing period taum, reconversion of the singlet-state populations remaining at the end of the mixing period taum into zero-quantum coherences ZQx and/or ZZ order, reversal of the sign of the zero-quantum coherences ZQx under the effect of the difference of the chemical shifts of the examined spins, and reconversion of zero-quantum coherences ZQx and/or ZZ order into single-quantum anti-phase coherences. With the broadband method for the excitation of single state population, NMR can monitor correlations between states that are connected through very slow processes.
Singlet-state exchange NMR spectroscopy for the study of very slow dynamic processes