Double-quantum solid-state NMR of 13C spin pairs coupled to 14N

We examine the double-quantum magic angle spinning NMR spectra of pairs of 13C nuclei coupled to one or more 14N nuclei. The experimental spectra of 13C(2)-glycine and glycyl-[13C(2)]-glycyl-glycine are used to demonstrate the sensitivity of the spectra to the orientation of 14N quadrupole interaction tensors and to the molecular torsional angles.