Publication
A method for heteronuclear decoupling in fast magic-angle spinning NMR measurements comprises application of a decoupling RF-pulse sequence with a decoupling-field amplitude 1⁄2 1 I on spins of a first nucleus and of an excitation pulse on spins of a second nucleus, the sequence comprising m blocks of pulses, with m ¥ 4, each block comprising an N-fold repetition of a pair of pulses with pulse width Ä p and phases whereby Ä p is equal for all pulses, whereby the phase of the pulse pair of the (i+1)-th block is inverted with respect to the pulse pair of the i-th block, with i=1 ... m-1 and i is an odd number, whereby the pulses within each pair are phase inverted, whereby a phase shift is carried out after each j-th block, with j is an even number. The efficiency of the inventive method compares favourably with CW, TPPM, SPINAL and XiX decoupling methods at medium and high RF amplitudes, particularly under rotary resonance conditions.
Geoffrey Bodenhausen, Fabien Ferrage