| The theoretical considerations and experimental techniques required to obtain ultra-high resolution solid state magic angle spinning nuclear magnetic resonance spectra of zeolites and related materials are presented. By preparing extremely highly crystalline, highly siliceous analogues of zeolites and careful optimization of all experimental parameters, it is possible to obtain {dollar}sp{lcub}29{rcub}{dollar}Si MAS NMR spectra with line widths of less than 6 Hertz at a frequency of 79.5 MHz. This hitherto unobtainable resolution for solid, inorganic crystalline samples allows for the complete deconvolution of the crystallographically inequivalent silicons and may aid in the deduction of unknown zeolite structures.; It is also shown that the ultra high degree of spectral resolution obtainable can be used as a very sensitive probe of crystallographically inequivalent tetrahedral sites in highly siliceous zeolites and related materials under varying conditions of temperature and sorbed organic molecules. Changes in the crystallographic symmetry of ZSM-39, ZSM-11 and ZSM-5 were detected as a result of temperature changes. By quantifying the change between crystallographically different phases of the zeolite ZSM-5 under conditions of varying concentrations of organic molecules and temperature, complete phase diagrams may be deduced.; Correlations between the {dollar}sp{lcub}29{rcub}{dollar}Si MAS NMR isotropic chemical shift and geometrical data derived from unambiguously assignable tectosilicates allows for the assignment of individual {dollar}sp{lcub}29{rcub}{dollar}Si NMR resonances to unique crystallographically inequivalent lattice positions for zeolites KZ-2, ZSM-12 and a high temperature, high symmetry form of ZSM-11. |
