Abstract
The specific photochemical reactivity of 2, 4, 6, 8(1H, 3H, 7H, 9H)-pyrimido[5, 4-g]pteridinetetrone 5-oxide (1), an effective photochemical oxygen-atom transfer agent, was discussed based on the results of molecular orbital (INDO/S-CI (intermediate neglect of differential overlap/spectrum-conflguration interaction)) calculations of the excited states, in comparison with several simple aromatic N-oxides, pyridine 1-oxide (2), pyrazine 1-oxide (3), acridine 10-oxide (4), and phenazine 5-oxide (5). The lowerst π-π* excited singlet (Sx-x*1) state of 1 was most characterized by the high proportion of the ψa2→ψ* transition for the CI (conflguration interaction) state and by the marked decrease of the N-O bond order, distinct from those of 2-5. The low reactivity in photorearrangement of 1 was interpreted to result from the decrease of the N-O bond order in the Sx-x*1 state. Also, the high photochemical oxygen-atom transfer reactivity of 1 was well correlated to the special features of the lowest unoccupied molecular orbital in the ground state.
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 callDisclaimer: 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.
