H-1-]P-31, P-31-]H-1, AND H-2-]H-1 CP MAS NMR-STUDIES OF THE LARGE-PORE GALLOPHOSPHATE MOLECULAR-SIEVE CLOVERITE/

Air-equilibrated cloverite containing normal and deuterated water was studied by H-1, P-31, and Ga-71 NMR with magic-angle spinning (MAS). T he spectra are assigned, and the H-1 and P-31 spin-lattice relaxation and the kinetics of H-1 --> P-31, P-31, H-1, and H-2 --> H-1 cross-pol arization (CP) are examined in detail. Spin diffusion between the obse rved spins (H-1 or P-31) has a significant effect on the relative inte nsities of lines in the CP spectra. The results indicate that cloverit e contains water-rich and water-deficient microdomains that contribute separately to the overall spectra. The water-rich microdomains contai n defect P-OH groups created by the hydrolysis of the Ga-O-P bonds.