SIMPLE TECHNIQUE FOR TEMPERATURE CALIBRATION OF A MAS PROBE FOR SOLID-STATE NMR-SPECTROSCOPY

A simple method is reported for temperature calibration of a magic angle spinning probe for solid-state NMR spectroscopy. The method is an extension of that developed by van Geet for temperature calibration of liquid-state MMR probes, and consists of measuring the frequency difference (Delta nu) between the resonances for the methyl and hydroxyl protons of methanol in the H-1 NMR spectrum of a simple of tetrakis(trimethylsilyl)silane soaked in liquid methanol. The successful application of this method for temperature calibration was demonstrated from an assessment, from high-resolution solid-state C-13 NMR spectroscopy, of the phase transition temperatures for solid tetrakis(trimethylsilyl)silane and for solid 2,2-dimethylpropane-1,3-diol.