Simultaneous and independent rotations with arbitrary flip angles and phases for I, ISα, and ISβ spin systems

A new pulse sequence element for simultaneous and independent rotations with arbitrary flip angles and phases for isolated I, ISalpha, and ISbeta resonances without the use of selective radiofrequency pulses is introduced and experimentally demonstrated. S is a directly attached heteronucleus either at natural abundance or isotopically enriched. This pulse sequence element, dubbed TIG-BIRD (triselective independent gyrations BIRD), generalizes earlier elements like BIRD, TANGO, BANGO, and BIG-BIRD, the latter of which allows for arbitrary selection of hip angles and phases for I and IS spin systems without discriminating between ISalpha and ISbeta resonances. For ISalpha and ISbeta spin systems it also generalizes the spin-state-selective excitation ((SE)-E-3) element selectively exciting only one of the ISalpha or ISbeta resonances. TIG-BIRD is a nonselective addition to the NMR toolkit which effects the equivalent of three independent selective rotations for I, ISalpha, and ISbeta resonances. (C) 1998 Academic Press.