Observation of singlet cycloreversion of thymine oxetanes by direct photolysis

Wai Ming Kwok, Xiangguo Guan, Lai Man Chu, Wenjian Tang, David Lee Phillips

Research output: Journal article publicationJournal articleAcademic researchpeer-review

10 Citations (Scopus)


An ultrafast broadband transient absorption spectroscopic study of the direct photolysis of oxetane DMT-BP [which is the oxetane adduct of 1,3-dimethylthymine (DMT) with benzophenone (BP)] is presented. Previous nanosecond time-resolved absorption studies by other researchers observed that direct photolysis of such oxetanes results in a rare, adiabatic photochemical reaction to produce a triplet excited-state carbonyl species. However, the mechanism for this adiabatic photochemical reaction remained unclear for the reaction sequence of the bond scission and the intersystem crossing (ISC) because of the time resolution for the experiments, and this prompted us to further study its mechanism with ultrafast time-resolution. The ultrafast time-resolved spectra presented here indicate that the cycloreversion reaction occurs in a stepwise manner on a singlet excited-state, and then intersystem crossing (ISC) occurs to produce the triplet carbonyl product observed in the previously reported nanosecond time-resolved experiments.
Original languageEnglish
Pages (from-to)11794-11797
Number of pages4
JournalJournal of Physical Chemistry B
Issue number37
Publication statusPublished - 18 Sept 2008

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Materials Chemistry
  • Surfaces, Coatings and Films


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