6533b7d7fe1ef96bd1269080
RESEARCH PRODUCT
Intramolecular Interactions in the Triplet Excited States of Benzophenone–Thymine Dyads
Salvador GilMaria J. ClimentSusana EncinasNoureddine BelmadouiMiguel A. Mirandasubject
PhotochemistryOrganic ChemistryGeneral ChemistryOxetaneHydrogen atom abstractionPhotochemistryCatalysisCycloadditionBenzophenoneschemistry.chemical_compoundchemistryEthers CyclicExcited stateIntramolecular forceBenzophenoneTriplet stateThymineThymidineMethyl groupdescription
Time-resolved and product studies on the synthesized dyads 1 and 2 have provided evidence that the benzophenone-to-thymine orientation strongly influences intramolecular photophysical and photochemical processes. The prevailing reaction mechanism has been established as a Paterno-Büchi cycloaddition to give oxetanes 3-6; however, the ability of benzophenone to achieve a formal hydrogen abstraction from the methyl group of thymidine has also been evidenced by the formation of photoproducts 7 and 8. These processes have been observed only in the case of the cisoid dyad 1. Adiabatic photochemical cycloreversion of the oxetane ring is achieved upon direct photolysis to give the starting dyad 1 in its excited triplet state. The photobiological implications of the above results are discussed with respect to benzophenone-photosensitized damage of thymidine.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2005-09-21 | Chemistry - A European Journal |