600 MHz Protonen Nitrogen HMBC
600 MHz: 1H-15N-HMBC
1H-15N-HMBC is basically the same as the classical HMBC (proton-carbon correlation) experiment, but as a result you obtain the 1H-15N-correlation.
In contrast to a 15N-NMR spectrum it is much moresensitive. Thus you need less time for a measurement. In one example (molecular weight 100 g/mol, concentration 30 mg/ml) it was possible to optai a good quality 1H-15N-HMBC-spectrum within 30 min. In order to obtain a 15N-NMR spectrum under the same conditionsone would need several hours.
In addition the 1H-15N-HMBC-spectrum has the advantage, that the correlation gives you additional information for structure elucidation.
Thus normally one should prefer an 1H-15N-HMBC-spectrum over a 15N-NMR spectrum.