The selective 1D HMQC-NOESY experiment is the selective version of the 2D HMQC-NOESY experiment. The experiment allows to obtain a selective 1D NOESY spectrum from the ¹H nucleus directly attached to the selected ¹³C nucleus. It can be an useful alternative to achieve 1D NOESY (or ROESY) spectra in high overlapped ¹H regions where conventional selective ¹H excitation is not feasible.

Easy implementation on AVANCE spectrometers equipped with an inverse probehead and selective excitation using shaped pulses.

The selective 1D HMQC-NOESY pulse sequence is easily derived from the conventional 2D HMQC-NOESY experiment in which one of the two 90º ¹³C pulses is made selective for a given ¹³C resonance and the variable evolution delay is fixed to a minimum value ( 90JMR600-90 ). In other words, it consists of a selective 1D HMQC pulse train followed by a NOESY block. A BIRD-recovery delay cluster can be incorporated as a preparation period to suppress the large and undesired ¹H-¹²C magnetization.
 
Related modified sequences have been proposed:

• The NOESY block can be replaced by a ROESY block (low-power continuous wave) yielding an analog selective 1D HMQC-ROESY experiment.
• Analog selective 1D HSQC-NOESY ( 93JMRB1-101 ) and selective 1D reverse-INEPT-NOESY experiments can also been designed for the same purpose.
• Better results are obtained from gradient-enhanced versions
• Selective ge-1D HMQC-NOESY experiment.
• Selective ge-1D HSQC-NOESY experiment.
• Selective ge-1D HMQC-ROESY experiment.
• Selective ge-1D HSQC-ROESY experiment.
• Use of a ¹³C chemical shift-selective filter ( 93JMRB1-101 ).

The selective 1D HMQC-NOESY  experiment can be recorded in a fully automated way. Minor changes from a predefined parameter set are required. The most important parameters to define is the NOESY mixing time and the selective ¹³C pulse: the offset, the shape, the duration and the power level needed for a specific excitation profile.

For further details on practical implementation of the selective 1D HMQC-NOESY  experiment on AVANCE spectrometers see Tutorial: selective 1D HMQC-NOESY experiment

The selective 1D HMQC-NOESY experiment affords a ¹³C-edited 1D NOESY spectrum from the selected ¹³C resonance. It can be an useful alternative to achieve 1D ¹H subspectra in high overlapped regions. The resulting spectrum is very similar to the conventional selective 1D NOESY spectrum: the direct response appears as a strong and negative large doublet due to ¹J(CH) if no ¹³C decoupling is applied during acquisition while all NOE enhancements from the directly-attached proton appears with positive intensity.