title: Thioformaldehyde S-Sulfide, Sulfur Analogue of the Criegee Intermediate: Structures, Energetics, and Rovibrational Analysis.
abstract: The ephemeral Criegee intermediate, first postulated over 70 years ago, has only recently been isolated in the gas phase. The sulfur analogue of this canonical zwitterion, thioformaldehyde S-sulfide, has eluded similar analysis; however, argon matrix isolation has been achieved ( Angew. Chem., Int. Ed. 2001 , 40 , 393 - 396 ). Here thioformaldehyde S-sulfide and its valence isomer dithiirane are examined with high-level coupled-cluster methods, including the minimum-energy pathway for interconversion. Relative enthalpies calculated from extrapolated energies at the complete basis set limit of the full CCSDTQ method are reported. Isomerization from thioformaldehyde S-sulfide to the lower-lying dithiirane (-7.2 kcal mol-1) is predicted to include a 27.0 kcal mol-1barrier. Harmonic and anharmonic vibrational frequencies are also predicted using second-order vibrational perturbation theory. These results should aid in future gas-phase identification.
authors.affiliation: Center for Computational Quantum Chemistry, University of Georgia , Athens, Georgia 30602, United States.
authors.forename: Kevin V
authors.initials: KV
authors.lastname: Murphy
authors.affiliation: Center for Computational Quantum Chemistry, University of Georgia , Athens, Georgia 30602, United States.
authors.forename: Whitney J
authors.initials: WJ
authors.lastname: Morgan
authors.affiliation: Center for Computational Quantum Chemistry, University of Georgia , Athens, Georgia 30602, United States.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Sun
authors.affiliation: Center for Computational Quantum Chemistry, University of Georgia , Athens, Georgia 30602, United States.
authors.forename: Henry F
authors.identifier: http://orcid.org/0000-0003-0252-2083
authors.initials: HF
authors.lastname: Schaefer
authors.affiliation: Center for Computational Quantum Chemistry, University of Georgia , Athens, Georgia 30602, United States.
authors.forename: Jay
authors.identifier: http://orcid.org/0000-0002-4052-4293
authors.initials: J
authors.lastname: Agarwal