Experimental aspects of multidimensional solid-state NMR correlation spectroscopy

The experimental parameters critical for the implementation of multidimensi onal solid-state NMR experiments that incorporate heteronuclear spin exchan ge at the magic angle are discussed. This family of experiments is exemplif ied by the three-dimensional experiment that correlates the H-1 chemical sh ift, H-1-N-15 dipolar coupling, and N-15 chemical shift frequencies. The br oadening effects of the homonuclear H-1-H-1 dipolar couplings are suppresse d using flip-flop (phase- and frequency-switched) Lee-Goldburg irradiations in both the H-1 chemical shift and the H-1-N-15 dipolar coupling dimension s. The experiments are illustrated using the H-1 and N-15 chemical shift an d dipolar couplings in a single crystal of N-15-acetylleucine. (C) 1999 Aca demic Press.