Time-reversed ODESSA experiment

For low-frequency motions (10 -10 s), the 2D exchange experiments are useful techniques (19). Other exchange experiments are also informative, e.g., the one-dimensional exchange spectroscopy by sideband alternation (ODESSA) (151), time-reversed ODESSA (152), and centerband-only detection of exchange (CODEX) (153). Many advanced techniques are given in a recent, excellent review by Brown and Spiess (14). 

D. Reichert, H. Zimmermann, T.P. Tekely, R. Poupko, Z. Luz, Time-reverse ODESSA. AID exchange experiment for rotating solids with several groups of equivalent nuclei, J. Magn. Reson. 125 (1997) 245—258. 

The ultraslow motions can be observed by exchange NMR experiments. There are a number of techniques, performed in ID and 2D modes which are based on the manipulation of spinning sidebands under MAS. The first of them, applied to study of solid peptides was ODESSA (one-dimensional exchange spectroscopy by sideband-alternation) [76] and next the time-reversed ODESSA [77] (tr-ODESSA). The interesting modification, which represents this group of sequences is CODEX (centreband-only detection of exchange) introduced by Schmidt-Rohr and coworkers [78]. CODEX can be executed at any MAS speed, while ODESSA and tr-ODESSA... 

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