Please use this identifier to cite or link to this item:
|Title:||Photochemical Ring-Opening and Intramolecular Hydrogen Shift Reactions in Sulfur Analogues of α-Pyrone||Authors:||Breda, S.
Cristiano, M. L. S.
|Issue Date:||May-2006||Publisher:||American Chemical Society||Serial title, monograph or event:||J. Phys. Chem. A||Volume:||110||Abstract:||A combined matrix isolation FTIR and theoretical DFT(B3LYP)/6-311++G(d,p) study of the photochemistry of sulfur analogues of α-pyrone [2H-thiopyran-2-one (TP) and 2H-pyran-2-thione (PT)] was carried out. The vibrational spectra of monomers of the compounds isolated in low-temperature argon matrixes were studied experimentally and assigned completely on the basis of theoretical calculations. UV irradiation (λ > 337 nm) of the studied compounds isolated in low-temperature matrixes results mainly in the ring-opening reaction by means of the cleavage of the α-bond. Other photoprocesses, not involving the α-bond-cleavage step (such as generation of Dewar valence isomer), correspond to the minor reaction channels in both studied compounds. The ring-opening photoreaction in PT represents the first reported case of an α-bond cleavage in a compound with a CS group attached to a six-membered ring, in which the internal strain practically does not exist, whereas the corresponding reaction in TP (a cleavage of a C−S bond in the α position with respect to a carbonyl group) is now reported for the first time. Following the ring-opening reactions, isomerization processes and intramolecular hydrogen shift reactions were observed, enabling production of TP from PT and vice versa. A detailed study of such processes was undertaken, and kinetical and mechanistical data are presented and discussed.||URI:||http://hdl.handle.net/10316/17918||DOI:||10.1021/jp061139k||Rights:||openAccess|
|Appears in Collections:||FCTUC Química - Artigos em Revistas Internacionais|
Show full item record
Files in This Item:
|J.Physical Chemistry A, 110 (2006) 6415.pdf||423.54 kB||Adobe PDF||View/Open|
checked on Feb 18, 2020
WEB OF SCIENCETM
checked on Feb 17, 2020
Page view(s) 50368
checked on Apr 2, 2020
checked on Apr 2, 2020
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.