Abstract

Photophysical data in cyclohexane solutions, including measurements of energies of lowest excited singlet and triplet states, fluorescence quantum yields, lifetimes, phosphorescence and triplet – singlet difference absorption spectra, reported in a previous Letter as due to methyl 4-halo-5-phenylisoxazole-3-carboxylates [S.M. Fonseca, H.D. Burrows, C.M. Nunes, T.M.V.D. Pinho e Melo, A.M.d’A. Rocha Gonsalves, Chem. Phys. Lett. 414 (2005) 98] are reassigned to the isomeric oxazoles. These are compared with data on the isoxazoles synthesised by an unambiguous route. In addition, results are presented on the photoinduced isomerization of 4-halo-5-phenylisoxazoles to oxazoles in cyclohexane, which is shown to proceed via a nonconcerted pathway, possibly involving thermal reaction of an azirine intermediate.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.