چكيده فارسي :
NMR spectroscopy is an integral part of modern chemistry. While the solution state NMR methods are well established, the intensive development in the field of solid-state NMR is a matter of last decades. Solid-state NMR is fascinating but highly difficult. Researchers entering this area need deep understanding of concepts and must also become reasonably familiar with experimental methods. Solid-state NMR spectroscopy is particularly useful as a structural method when: (i) the sample is amorphous, inhomogeneous, without long range order, or only very small crystallites are available (ii) the sample is insoluble, or decomposes in solution (iii) it is the structure of the solid itself that is the subject of interest. Solid state NMR spectroscopy has found numerous applications for the determination of the types of hydroxyl proton in zeolites, of their concentration, accessibility, and mobility, and for the characterization of their acid strength and local structure [1]. Solid-state nuclear magnetic resonance (NMR) spectroscopy has long been established as offering unique atomic-scale and element-specific insight into the structure, disorder, and dynamics of materials. Single-crystal X-ray diffraction has been used to determine the structure of a silicate hydrate. Magic-angle spinning 13C, 29Si and 1H NMR spectra are consistent with the crystallographic asymmetric unit [2]. Dipolar dephasing can be applied for quantitatively differentiating protonated and non-protonated and molecularly mobile and rigid components in soil organic matter [3]. The dynamics behavior of guest molecules adsorbed within the cavities and channels of nanoprous zeolite can be studied by solid-state 13C-NMR dipolar dephasing experiments [4].
