1,1,1,2-tetrafluoroethane photofragmentation: a translational kinetic energy release analysis in the EUV and X-ray energies range

Abstract

A molecule with two or more atoms of the same element in distinct chemical environments is a trial system for probing site-specific fragmentation. In this context, special attention is deserved to 1,1,1,2-tetrafluoroethane (CF₃CH₂F), which has been the subject of numerous studies. This work discusses the effects of extreme ultraviolet (EUV) and soft X-ray irradiation on CF₃CH₂F from a dedicated translational kinetic energy release (KER) perspective. This analysis is achieved by evaluating the mean KER for its fragments at photon energies over 30–320 eV and computing the KER distribution (KERD) for the main fragments over the 282–320 eV range. The questions of interest from the point of view of the present study are twofold: (i) How do the mean KER of ionic fragments of the valence or core-excited CF₃CH₂F molecule change as a function of incident photon energy? (ii) Is there any evidence of site-specific or state-specific dissociation mechanisms in a molecule containing two carbon atoms in distinct chemical environments? From our results, lighter fragments showed to have their mean KER virtually following respective ion yields previously reported. And the overall learning is that the chemical environment associated with each C 1s excitation plays a role in differentiating the KER results.

GRAPHICAL ABSTRACT

KEYWORDS:

• Photofragmentation
• HFC-134a
• kinetic energy release
• KER distribution
• site-specific fragmentation

Acknowledgements

This research used resources of the Brazilian Synchrotron Light Laboratory (LNLS), an open national facility operated by the Brazilian Centre for Research in Energy and Materials (CNPEM). The TGM beamline staff is acknowledged for the assistance during the experiments. The authors are also thankful to the reviewers for their valuable comments, criticisms, and suggestions.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Part of the data that support the findings of this study are openly available in Figshare at https://doi.org/10.6084/m9.figshare.20224059.v1.

Additional information

Funding

This work has been financially supported by CNPq, Financiadora de Estudos e Projetos (FAPERJ), Fundação Carlos Chagas Filho de Amparo á Pesquisa do Estado do Rio de Janeiro (FINEP) and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) (Programa Nacional de Pós-Doutorado – PNPD). It has also been financed partly by the CAPES Finance Code 001.