The Off-resonance ROESY block ( 99PROG295 ) is an improved variant of the conventional ROESY block in which the ROESY process is applied some KHz off-resonance from the center of the spectrum. The advantage over the NOESY block is that Overhauser enhancement is always positive, never approaching zero.

Easy implementation on AVANCE spectrometers.

 See  2D ROESY and related experiments.

The standard way to implement an off-resonance ROESY block is:

... p1 ph3 d13 d12 fq1:f1 d12 pl0:f1 p15:sp10:f1 ph2:r d13 d12 fq1:f1 d12 pl1:f1 p1 ph4 ...

in which:

• p15 is the mixing ROESY pulse (in usec) applied at low power level sp10 from the f1 channel using a shape defined in spnam10 (Squaramp,20.1000).
• Frequencies (fq1) are taken from a FQ1LIST: on resonance for detection and off resonance for spinlock.
• d12 is the minimum delay (20 msec) to set power levels and frequencies.
• The phases may be specified at the end of pulse program.

 See  2D ROESY and related experiments.