Magnitude and absolute orientation of H-1 chemical shielding tensors in polycrystalline powders: a H-1 CRAMPS NMR study of KH2PO4

It is shown that the magnitude and absolute orientation of H-1 chemical shi elding tensors may be determined from polycrystalline powders using combine d rotation and multiple pulse spectroscopy (CRAMPS) by simultaneous evoluti on under chemical shielding and heteronuclear dipolar coupling interactions . An experimental approach based on the broadband high-order truncating MSH OT-3 homonuclear decoupling sequence is demonstrated for the hydrogen bonde d proton within the P-31-H-1-P-31 three-spin systems of a powder of KH2PO4. (C) 1999 Elsevier Science B.V. All rights reserved.