Computational Investigation of the Sulfur Analog of the Criegee Intermediate

The ephemeral Criegee intermediate, first postulated over 70 years ago, has only recently been isolated in the gas phase. The sulfur analog of this canonical zwitterion, thioformaldehyde S-sulfide, has eluded similar analysis; however, argon matrix isolation has been achieved. In the present research, thioformaldehyde S-sulfide and its valence isomer dithiirane are examined with high-level electronic structure methods, including the minimum energy pathway for interconversion. Relative enthalpies and fundamental frequencies are presented