Solid-state dipolar INADEQUATE NMR spectroscopy with a large double-quantum spectral width.

A technique for obtaining dipolar-mediated INADEQUATE NMR spectra with a large spectral window in the double-quantum dimension is presented. Using the dipolar recoupling sequence C7 to excite the double-quantum coherence under magic-angle spinning, the technique involves incrementing the evolution period in synchrony with the phase of the radiofrequency pulses in the C7 sequence. The technique is demonstrated on a uniformly 13C-labeled amino acid and an extensively 13C-labeled protein to identify 13C connectivity patterns for spectral assignment.