The Reactions of Sulfur Atoms. VII. The Ultraviolet Spectrum, the Photolysis, and the Mercury Sensitization of Carbonyl Sulfide

K. S. Sidhu, O. P. Strausz, H. E. Gunning, I. G. Csizmadia

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Ultrapure gaseous COS exhibits a broad absorption continuum in the near-ultraviolet region which starts at 2550 A and extends to below 2000 A with a rounded maximum at 2225 A. Semiempirical molecular orbital calculations, with the inclusion of the sulfur d orbitals, indicate this continuum to correspond to a π→ π* transition since the lowest lying n → π* type state appears at considerably higher energies. Photolysis in this region affords CO (ψ = 1.81 at 2537 and 2288 A) and sulfur. The primary step yields S atoms at least 74% of which are formed in the excited (1D) state. The mercury photosensitization at 2537 A affords only triplet-ground-state sulfur atoms. Both singlet- and triplet-state atoms abstractively attack COS to form S2 with the rate ratio, S(1D)/S(3P), being ca. 30. The condensed-phase photolysis is similar to that of the gas phase although the relative yields of triplet- and singlet-state atoms may be altered.

Original languageEnglish
Pages (from-to)2412-2417
Number of pages6
JournalJournal of the American Chemical Society
Issue number11
Publication statusPublished - Jun 1 1966


ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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