3-DIMENSIONAL NUCLEAR-MAGNETIC-RESONANCE EXCHANGE SPECTROSCOPY WITH ROTARY RESONANCE IN ROTATING SOLIDS - APPLICATION TO TROPOLONE DYNAMICS

A three-dimensional nuclear magnetic resonance (NMR) experiment is des cribed for the investigation of molecular rearrangements in the course of chemical exchange processes. The experiment relies on the two-dime nsional correlation of the chemical shift tensors before and after exc hange. The chemical shift tensors are retrieved under fast magic angle spinning by rotary resonance induced by a radio-frequency held whose magnitude matches the sample spinning frequency. The third dimension s erves for the separation of the two-dimensional chemical shift pattern s by the isotropic chemical shifts. The three-dimensional rotary-reson ance C-13-exchange experiment is demonstrated with an investigation of hydrogen-transfer and molecular diffusion processes in a sample of so lid tropolone. (C) 1998 American Institute of Physics.