Double proton transfer dynamics of model DNA base pairs in the condensed phase
Cited 81 times inCited 76 times in
- Double proton transfer dynamics of model DNA base pairs in the condensed phase
- Kwon, Oh Hoon; Zewail, Ahmed H.
- Issue Date
- NATL ACAD SCIENCES
- PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, v.104, no.21, pp.8703 - 8708
- The dynamics of excited-state double proton transfer of model DNA base pairs, 7-azaindole dimers, is reported using femtosecond fluorescence spectroscopy. To elucidate the nature of the transfer in the condensed phase, here we examine variation of solvent polarity and viscosity, solute concentration, and isotopic fractionation. The rate of proton transfer is found to be significantly dependent on polarity and on the isotopic composition in the pair. Consistent with a stepwise mechanism, the results support the presence of an ionic intermediate species which forms on the femtosecond time scale and decays to the final tautomeric form on the picosecond time scale. We discuss the results in relation to the molecular motions involved and comment on recent claims of concerted transfer in the condensed phase. The nonconcerted mechanism is in agreement with previous isolated-molecule femtosecond dynamics and is also consistent with the most-recent high-level theoretical study on the same pair.
- Appears in Collections:
- CHM_Journal Papers
- Files in This Item:
- There are no files associated with this item.
can give you direct access to the published full text of this article. (UNISTARs only)
Show full item record
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.