Efficient heteronuclear decoupling by quenching rotary resonance in solid-state NMR

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.