Fullerene as a Standard Sample for Adjusting the NMR Spectral Resolution in Multiple-Quantum Magic-Angle-Spinning Experiments

Abstract

A method using fullerene for adjusting the NMR spectral resolution for multiple quantum magic angle spinning (MQMAS) experiments is proposed. To observe its ¹³C MAS signal, it is not necessary to apply ¹H decoupling, unavailable with single-resonance MQMAS probes. Although ¹³C T₁ of fullerene is rather long, a recycle time of 5 s in shimming yields its signal with sufficiently high sensitivity if setting the appropriate Ernst angles corresponding to magnetic fields. It is demonstrated that so-adjusted high resolution is reflected in the ⁸⁷Rb MQMAS spectra of RbNO₃.