Time-resolved dynamics in iodide-uracil-water clusters upon excitation of the nucleobase

J Chem Phys. 2019 Oct 21;151(15):154304. doi: 10.1063/1.5120706.

Abstract

The dynamics of iodide-uracil-water (I-·U·H2O) clusters following π-π* excitation of the nucleobase are probed using time-resolved photoelectron spectroscopy. Photoexcitation of this cluster at 4.77 eV results in electron transfer from the iodide moiety to the uracil, creating a valence-bound anion within the cross correlation of the pump and probe laser pulses. This species can decay by a number of channels, including autodetachment and dissociation to I- or larger anion fragments. Comparison of the energetics of the photoexcited cluster and its decay dynamics with those of the bare iodide-uracil (I-·U) complex provides a sensitive probe of the effects of microhydration on these species.

MeSH terms

  • Electrons
  • Iodides / chemistry*
  • Iodides / radiation effects
  • Oxidation-Reduction
  • Photoelectron Spectroscopy
  • Ultraviolet Rays
  • Uracil / chemistry*
  • Uracil / radiation effects
  • Water / chemistry*

Substances

  • Iodides
  • Water
  • Uracil