Solid-State NMR Studies of Molecular Crystals

Usually in studies of crystalline solids, X-ray diffraction is regarded as a method of choice. In this review, we aim at demonstrating that there are more and more frequent cases, in which the solid-state nuclear magnetic resonance (SS NMR) holds an advantage over classic crystallography techniques. To that purpose, we firstly give a short introduction to very fast magic angle spinning NMR of solid samples, as due to the introduction of this methodology a significant progress in the NMR measurements of solids took place. Then, 2D and 3D NMR experiments of solids are briefly described, and the role of the dynamic nuclear polarization enhancement of an NMR signal in the further development of SS NMR is underlined. In the next chapters, we give a selection of recent works on the applications of SS NMR in molecular crystals analysis, aiming at giving the broadest possible variety of examples, starting from inorganic and hybrid inorganiceorganic crystals, through classic organic crystals and cocrystals, and ending with a description of the solid-state processes, occurring in molecular crystals, which can be followed with SS NMR. Finally, a review of theoretical methods supporting, complementing and rationalizing the results obtained from SS NMR measurements of molecular crystals is given.