Broad-band excitation in indirectly detected 14 N overtone spectroscopy with composite pulses
Résumé
We show here that composite pulses allow broad-band excitation of nitrogen-14 overtone frequencies in proton detected D-HMQC experiments (referred to 1H-{} D-HMQC). Experimental verifications have been performed on glycine, L-histidine and N-acetyl-valine (NAV) samples. Composite pulses enable symmetric excitations of 14N sites with large shift differences. Therefore, this approach is promising for recording high resolution 1H-{} D-HMQC spectra of most amino-acids, pharmaceutical samples and peptides.