Photochemical formation of thiirene and thioketene in 1,2,3-thiadiazoles with phenyl substituents studied by time-resolved spectroscopy

G. Burdzinski (1) , M. Sliwa (2) , Y. Zhang (3) , S. Delbaere (2) , T. Pedzinski (4) , J. Réhault (5)

1 Quantum Electronics Laboratory
2 LASIRE - Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516
3 Koch Institute for Cancer Research
4 Faculty of Chemistry
5 UZH - Universität Zürich [Zürich] = University of Zurich

Photochemistry of 4-phenyl-1,2,3-thiadiazole (PT) and 4,5-diphenyl-1,2,3-thiadiazole (DPT) in solution was studied at room temperature using UV-vis and IR transient absorption spectroscopies (λ_ex = 266 nm). Ultrafast techniques show a very fast rise (<0.3 ps) of thiirene and thioketene species, formed from 1,2,3-thiadiazoles in the singlet excited state. The remarkable unimolecular stability of thiirenes in solution is observed. On a millisecond time scale thiirenes with phenyl substituents undergo an intermolecular reaction (dimerization of thiirene-thioketene complexes) leading to 1,3-dithiole derivatives.

Domaines: Chimie théorique et/ou physique

G. Burdzinski, M. Sliwa, Y. Zhang, S. Delbaere, T. Pedzinski, et al.. Photochemical formation of thiirene and thioketene in 1,2,3-thiadiazoles with phenyl substituents studied by time-resolved spectroscopy. Photochemical & Photobiological Sciences , 2013, 12, pp.895 - 901. ⟨10.1039/C3PP25453D⟩. ⟨hal-00829612⟩