Homonuclear decoupling has been used to simplify the spectrum and to enhance the corresponding signal-to-noise ratio. However, low-power broadband decoupling sequences generate large far-from-resonance frequency modulation which preclude selectivity. Selective band-decoupling can be achieved by using shaped inversion pulses combined in the same way as MLEV or WALTZ schemes ( 91JMR653-93 , 92JMR426-97 , 92JMR604-100 ). For instance, several approaches have been proposed:
- SEDUCE schemes ( 92JACS2108 , 92JMR674-98 , 93JMRA122-101 )
- Effective schemes using I-BURP-2 inversion pulses ( 93JMRA364-102 and 95JMRB329-109 )
- Effective schemes using G3 inversion pulses ( 94JACS8847 and 95JMRB329-109 )
- Effective schemes using sech/tanh inversion pulses ( 95JMRA126-112 )
- Use of amplitude-modulated pulse builded from a series of Fourier components, SWIRL scheme ( 97JMR376-125 ).
- Double band-selective decoupling can be achieved using the Double-WURST scheme ( 96JMRA181-123 ).
- Multiple-band selective decoupling during acquisition ( 05JB1-31 ). Interesting in 13C detected experiments.
- The so-called BEST scheme which eliminates Bloch-Siegert shift effects and also the residual sidebands ( 99JMR281-138 ).
Homonuclear decoupling ( B99KRI149) has been used intensively in double- and triple-resonance multidimensional experiments:
More about selective adiabatic inversion pulses : 97JMR221-126 and 97JMR115-129 .