Lanthanide shifts in the 1H N.M.R. spectra of thioamides, selenoamides and 1,2-dithioles

Abstract

The effects of lanthanide shift reagents on the spectra of thioamides and related amides and selenoamides are reported, and compared with those in related sulphur compounds including 1,2-dithioles. The thiocarbonyl group in a thioamide is less effective as a complexing site than is the amide carbonyl, but more effective than the sulphur of a thioether. Small but useful shifts are observed for selenoamides.