Acquisition of ultra-wideline NMR spectra from quadrupolar nuclei by frequency stepped WURST–QCPMG

Ultra-wideline NMR spectra of quadrupolar nuclei have been obtained using a frequency stepped WURST–QCPMG pulse sequence. This method offers a significant advantage over other frequency stepped techniques due to the much wider excitation bandwidth of the WURST pulses. The incorporation of proton decoupling leads to further signal enhancement in certain cases. The experiment is shown to be applicable to central and satellite transitions of half-integer quadrupoles and also to integer spin nuclei. Frequency stepped WURST–QCPMG is the most efficient way of obtaining ultra-wideline NMR spectra yet reported, and increases the opportunity to study nuclei that were previously considered inaccessible.