an interesting isomerization: synthesis of mesoionic 5-arylamino-1,3,4-thiadiazolium-2-thiolates by using ω-bromo-ω-(1H-1,2,4-triazol-1-yl)acetophenone as catalyst

Article abstract of DOI:10.1002/jccs.200000129

Mesoionic 5-arylamino-1,3,4-thiadiazolium-2-thiolates 7a-f were prepared by the isomerization of 5-arylamino-1,3,4-thiadiazol-2-thiones 5a-f by using ω-bromo-ω-(1H-1,2,4-triazol-1-yl)acetophenone 6 as catalyst. All the structures of mesoionic synthesized were confirmed by elemental analyses, ¹H NMR, IR and MS spectral data. We have also determined the x-ray photoelectron spectroscopy (XPS) of the mesoionic and their precursors. A comparison of XPS spectra between the mesoionic and their precursors showed that the charge separation in mesoionic is distinctly larger than in their precursors.