Two dimensional Zeeman nuclear quadrupole resonance spectroscopy

We describe the first application of two-dimensional spectroscopy to the pure quadrupole regime. One- and two-pulse Zeeman perturbed experiments are outlined, and results of a one-pulse experiment on the two crystallographically nonequivalent ³⁵Cl sites in 2,4,6-trichloro-1,3,5-triazine ("cyanuric chloride") are presented. The results demonstrate that the overlapping Zeeman-perturbed resonances in a one-dimensional experiment are fully resolved in a two-dimensional experiment. The methods appear to have considerable utility for the determination of the quadrupole coupling constant e²qQ/h and asymmetry parameter η for spin I=3/2 nuclei in systems with several closely spaced pure nuclear quadrupole resonance lines.