Advanced Solid State NMR Techniques for the Characterization of Sol–Gel-Derived Materials

A large array of advanced solid state NMR (nuclear magnetic resonance) techniques is presented in the frame of the structural characterization of sol-gel-derived materials. These techniques include the pertinent detection of (17)O chemical shifts, MAS (magic angle spinning) J spectroscopy in the solid state, high-resolution (1)H spectroscopy, heteronuclear and homonuclear D (dipolar)-derived multidimensional correlation experiments, and first-principles calculations of NMR parameters. This spectroscopic approach is suitable for the in-depth description of multicomponent sol-gel derivatives, crystalline and amorphous biocompatible silicophosphates, Al-O-P clusters, and templated porous materials. It offers unique perspectives for the description of the hybrid interfaces in terms of chemical and spatial connectivities.