Excited-state dynamics of cytosine tautomers

J Am Chem Soc. 2009 Nov 25;131(46):16939-43. doi: 10.1021/ja907355a.

Abstract

We report the relaxation dynamics of keto and enol or keto-imino cytosine, photoexcited in the wavelength range of 260-290 nm. Three transients with femtosecond to hundreds of picoseconds lifetimes are observed for the biologically relevant keto tautomer and are assigned to internal conversion and excited-state tautomerization. Only two transients with femtosecond and picosecond lifetimes are identified for the enol or keto-imino tautomer and are assigned to internal conversion processes. The results are discussed in the context of published ab initio theory.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cytosine / chemistry*
  • DNA / chemistry*
  • DNA / radiation effects*
  • Isomerism
  • Photochemical Processes

Substances

  • Cytosine
  • DNA