Fast Wide-Line Solid-State NMR on a Low-Cost Benchtop Spectrometer

Abstract

Solid-state NMR may provide access to a wealth of information on molecular structure and dynamics. However, for many applications, the acquisition is challenged by broad resonances implying large spectral linewidths and low sensitivity. Conventionally, this is tackled by using costly and laboratory-fixed spectrometers based on large high-field superconducting magnets. In this Communication, we demonstrate that a range of challenging wide-line solid-state NMR spectra can be acquired on a robust, maintenance-free, low-cost benchtop/mobile NMR spectrometer with a sensitivity comparable to common high-field instruments. The performance and versatility for recording sensitive wide-line spectra is demonstrated through acquisition of ³¹ P NMR of paramagnetic FePO₄ and full quadupolar lineshapes of Al₂ O₃ (²⁷ Al) and KNO₃ (¹⁴ N). Also, we introduce interleaved acquisition of frequency-stepped slices providing a dramatic reduction of the required experiment time.

Keywords: NMR spectroscopy; analytical methods; low-field NMR; sensors; solid-state structures..