Solid-State Multiple-Quantum NMR Spectroscopy: An Insight into the Structure of Inorganic Materials

Abstract

The review brings a brief introduction into the current trends of modern solid-state NMR spectroscopy of quadrupolar nuclei such as ²⁷Al and ²³Na which form a significant components of inorganic materials. The recently deve­loped two-dimensional technique of multiple-quantum NMR spectroscopy provides detailed structure analysis of inorganic and organic materials. The advantage of this technique is multiple in characterizing complex amorphous systems. The potentials of this technique in the ana­lysis of ²⁷Al MQ/MAS (multiple-quantum magic-angle spinning) NMR spectra of crystalline kyanite and amorphous inorganic polymers are demonstrated. Special processing of the obtained experimental data known as biaxial shearing is also discussed. It is shown that the new approaches provide information on structure in a synoptical form, making interpretation of MQ/MAS NMR data much easier.