Synthesis, 1H NMR Spectral Properties and Conformational Preferences of some Open-chain and Cyclic Aromatic Sulphides Containing Pyridine or 1,3,4-Thiadiazole Units

Article abstract of DOI:10.1002/mrc.1270160102

The conformational preferences in solution of eight new open-chain and cyclic aromatic sulphides containing pyridine or 1,3,4-thiadiazole units have been investigated, parallel to those of some structurally related phenyl sulphides, by means of 1H NMR spectroscopy.The results obtained have shown that replacement of phenyl by the pyridyl or the 1,3,4-thiadiazolyl moieties induces slightly different propeller arrangements, ascribed to the higher conjugative tendency of both electron-deficient heteroaromatic rings, in all open-chain mixed sulphides, in opposition to the skew arrangements observed for phenyl sulphide derivatives.No prominent differences have been found for cyclic sulphides, which preferentially adopt the sterically unhindered saddle shape conformation.