A NEW MULTIPLE-PULSE CYCLE FOR HOMONUCLEAR DIPOLAR DECOUPLING

A new 24-pulse cycle is introduced for homonuclear dipolar decoupling. The cycle is composed of four composite dipolar-decoupling inversion pulses which are in turn each composed of three solid-echo pulse pairs. The composite inversion pulses are each dipolar-decoupling to zero order including finite pulse widths, and to second order in the delta-function RF pulse approximation. All odd-order terms in the Magnus expansion vanish by symmetry over half the 24-pulse cycle. The cycle has a scaling factor only slightly smaller than BR-24 and appears to be much more forgiving of experiment imperfections than either BR-24 or MREV-8. Examples are shown for malonic acid and adipic acid. © 1991.