The role of electron transfer in the fragmentation of phenyl and cyclohexyl boronic acids

Ana Isabel Lozano, Beatriz Pamplona, Tymon Kilich, Marta Łabuda, Mónica Mendes, João Pereira-Da-Silva, Gustavo García, Pedro M. P. Góis, Filipe Ferreira da Silva, Paulo Limão-Vieira

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

In this study, novel measurements of negative ion formation in neutral potassium-neutral boronic acid collisions are reported in electron transfer experiments. The fragmentation pattern of phenylboronic acid is comprehensively investigated for a wide range of collision energies, i.e., from 10 to 1000 eV in the laboratory frame, allowing some of the most relevant dissociation channels to be probed. These studies were performed in a crossed molecular beam set up using a potassium atom as an electron donor. The negative ions formed in the collision region were mass analysed with a reflectron time-of-flight mass spectrometer. In the unimolecular decomposition of the temporary negative ion, the two most relevant yields were assigned to BO and BO2 . Moreover, the collision-induced reaction was shown to be selective, i.e., at energies below 100 eV, it mostly formed BO, while at energies above 100 eV, it mostly formed BO2 . In order to further our knowledge on the complex internal reaction mechanisms underlying the influence of the hybridization state of the boron atom, cyclohexylboronic acid was also investigated in the same collision energy range, where the main dissociation channel yielded BO2 . The experimental results for phenyl boronic acid are supported by ab initio theoretical calculations of the lowest unoccupied molecular orbitals (LUMOs) accessed in the collision process.

Original languageEnglish
Article number5578
JournalInternational Journal of Molecular Sciences
Volume20
Issue number22
DOIs
Publication statusPublished - 2 Nov 2019

Keywords

  • Boronic acids
  • Electron transfer
  • Negative ion formation
  • TOF mass spectrometry

Fingerprint Dive into the research topics of 'The role of electron transfer in the fragmentation of phenyl and cyclohexyl boronic acids'. Together they form a unique fingerprint.

  • Cite this