On the gas phase fragmentation of protonated uracil : a statistical perspective.

Abstract : The potential energy surface of protonated uracil has been explored with an automated transition state search procedure, resulting in the finding of 1398 stationary points and 751 reactive channels, which can be categorized into isomerizations between pairs of isomers, unimolecular fragmentations and bimolecular reactions. The use of statistical Rice-Ramsperger-Kassel-Marcus (RRKM) theory and Kinetic Monte Carlo (KMC) simulations allowed us determining the relative abundances of each fragmentation channel as a function of the ion's internal energy. The KMC/RRKM product abundances are compared with novel mass spectrometry (MS) experiments in the collision energy range 1-6 eV. To facilitate the comparison between theory and experiments, further dynamics simulations are carried out to determine the fraction of collision energy converted into the ion's internal energy. The KMC simulations show that the major fragmentation channels are isocyanic acid and ammonia losses, in good agreement with experiments. The third predominant channel is water loss according to both theory and experiments, although the abundance obtained in the KMC simulations is very low, suggesting that non-statistical dynamics might play an important role for this channel. Isocyanic acid (HNCOH +) is also an important product in the KMC simulations, although its abundance is only significant at internal energies not accessible in the MS experiments.
Document type :
Journal articles
Complete list of metadatas

Cited literature [46 references]  Display  Hide  Download

https://hal.archives-ouvertes.fr/hal-01386210
Contributor : Riccardo Spezia <>
Submitted on : Wednesday, February 13, 2019 - 2:38:58 PM
Last modification on : Tuesday, February 26, 2019 - 1:43:58 PM
Long-term archiving on : Tuesday, May 14, 2019 - 6:47:36 PM

File

Uracil_pccp_rev_HAL.pdf
Files produced by the author(s)

Identifiers

Citation

Estefania Rossich-Molina, Jean-Yves Salpin, Riccardo Spezia, Emilio Martinez-Nunez. On the gas phase fragmentation of protonated uracil : a statistical perspective.. Physical Chemistry Chemical Physics, Royal Society of Chemistry, 2016, 18, pp.14980. ⟨10.1039/c6cp01657j⟩. ⟨hal-01386210⟩

Share

Metrics

Record views

164

Files downloads

104