| Abstract
| - 3,6-Bis(trifluoromethyl)- and 3,6-bis(pentafluoroethyl)-1,2-dithiin (1a,b), the first known perfluoroalkyl-substituted 1,2-dithiins, were synthesized from (Z,Z)-1,4-bis(tert-butylthio)-1,3-butadiene(2) to evaluate the effects of electron-withdrawing groups on the ionization and oxidation potentialsof 1,2-dithiins. Analysis of the photoelectron spectra of 1a and 1b provided a basis for assigningorbital compositions. Ab initio calculations on these compounds showed that they adopt a twistgeometry as does 1,2-dithiin (1c) itself. Cyclic voltammetric studies on 1a and 1b revealed areversible oxidation followed by an irreversible oxidation at much more positive potentials thanfor 1,2-dithiin and 3,6-dimethyl-1,2-dithiin (1d). The oxidation potentials determined electrochemically do not correlate with the ionization potentials determined by photoelectron spectroscopy. Thisresult supports the previously advanced hypothesis that there is a geometry change on electrochemical oxidation leading to a planar radical cation.
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