O-17 MULTIPLE-QUANTUM AND H-1 MAS NMR-STUDIES OF ZEOLITE ZSM-5

Oxygen-17 multiple-quantum magic-angle spinning nuclear magnetic reson ance studies were performed, for the first time, in the high field of 17.6 T. A good resolution between two oxygen signals due to SiOSi and SiOAl fragments could be obtained. From the residual linewidth of the SiOSi signal, it is concluded that a change of the bridging SiOSi angl e by 13.4 degrees gives rise to a quite large change in the isotropic chemical shift of less than 5.7 ppm. (C) 1998 Elsevier Science B.V.