NMR studies of chemical exchange amongst five conformers of a ten-membered ring compound containing two amide bonds and a disulfide†

This paper presents experimental measurements which provide a very detailed picture of the free energy surface of a molecule. The compound, N,N′-dimethyl-N,N′-(2,2′-dithiobisacetyl)ethylenediamine (a diamino–disulfide, DADS, chelate), is a symmetrical ten-membered ring compound. Five conformers with significant populations are observed in dimethylformamide solution at 300 K. The ring consists of a pair of methylene groups at the top, each of …