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A two-dimensional solid state NMR experiment which combines rotary echoes and nutation NMR is investigated and used to study different sodium sites in zeolite NaA. It is shown that with this technique sodium ions with different relaxation rates in the rotating frame can be distinguished.

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010ChemInform Abstract From two-dimensional 23Na spectra of zeolite NaA as a function of water content the following can be concluded: In dry NaA two Na sites can be detected, at the 6-rings and at the 8/4-rings. The first water molecules are absorbed at the 8/4-rings. When the amount of absorbed water is increased in steps, first the quadrupole interaction of Na at the 6-rings decreases; with more absorbed water the quadrupole interaction of the Na ions at the 8-rings becomes small. Relaxation effects in the rotating frame indicate a mobility of Na ions or water molecules. The two-dimensional nutation technique is proved to be very useful for the study of quadrupolar nuclei in zeolites.