Homonuclear correlation experiments of half-integer quadrupolar nuclei using multiple-quantum techniques spinning at a P(4) magic angle.

Abstract

A new approach for obtaining structural information in half-integer quadrupolar nuclei is proposed and demonstrated. In this method, the two-dimensional multiple-quantum experiment is performed, spinning at one of the angles at which the fourth order Legendre polynomial vanishes (P4 magic angle). In such an experiment, the dipolar interaction is retained, whereas the second-order quadrupolar broadening is refocused by the MQ-1Q correlation scheme. By adding an exchange period to this pulse scheme, we performed efficient homonuclear correlation experiments in a regular magic angle spinning probe with minor modifications. The experiment is demonstrated on a model compound, and the results are briefly discussed.