Spatial ordering of organic and inorganic charge centers in as-made high-silica zeolites determined by multidimensional {1H}-> H-2 CPMAS NMR correlation spectroscopy

Evidence is presented for the spatial ordering of the organic and inorganic charge centers in the as-made tectosilicates nonasil, SSZ-23, and ZSM-12. This result is based on two-dimensional H-2-{H-1} NMR correlation spectrosc opy experiments, which show correlation between the silanol protons of the defect site and the N-methyl groups of the structure-directing agent. The t wo-dimensional NMR spectra for all samples suggest that the deuterons of th e methyl groups adjacent to the organic charge center are preferentially or dered relative to the defect site. Experiments performed on a sample synthe sized in D2O are consistent with the interpretation of the two-dimensional NMR experiments. The results also suggest that Coloumbic organic-inorganic forces influence the location of the charge-compensating defect site in all -silica zeolites. Moreover, we suggest an additional role for certain catio nic structure-directing agents in zeolite synthesis, controlling the locati on of T+3 atoms in the zeolite framework.