High-resolution two-dimensional NMR spectra of half-integer-spin quadrupolar nuclei from one-dimensional projections

We present a technique providing high-resolution spectra of quadrupolar nuclei with half-integer nuclear spin displaying significant second-order linebroadening. The technique, dubbed chemical shift – quadrupolar projection-reconstruction of one-dimensional spectra (CQ-PRODI) exploits the different magnetic field dependence of the chemical shift and second-order quadrupolar effect. One-dimensional spectra recorded at different magnetic field strengths are represented as projections along different directions in the two-dimensional spectrum that correlates the chemical shift and the second-order quadrupolar lineshape. We present CQ-PRODI spectra for 27Al in 9Al2O3 · 2B2O3 and for 71Ga in β-Ga2O3 which display resolution of all sites in the chemical shift dimension.