Mass-spectrometric identification of the tautomeric forms of bisthiocarbonohydrazones of ketones in the gaseous phase

Electron-impact mass spectrometry was used to identify the 2-hydrazono-1,3,4-thiadiazolidone form and linear tautomeric forms of bisthiocarbonohydrazones of acetone, pinacolone, and acetophenone. For the derivatives para-nitro- and para-methoxyacetophenone in the gaseous phase, a third possible 1,2,4-triazolidine-3-thione tautomer was detected in addition to the other two. Ions characterizing each of the tautomeric forms were found in the mass spectra of bisthiocarbohydrazones of acetophenones.