Jump to main content
Jump to site search

Issue 39, 2018
Previous Article Next Article

Chain-propagation, chain-transfer, and hydride-abstraction by cyclic carbocations on water surfaces

Author affiliations

Abstract

Atmospheric particles contain a wide range of oligomers, but the formation mechanism and the origin of complexity are still unclear. Here, we report the direct detection of carbocationic oligomers generated from the exposure of a series of cyclic unsaturated hydrocarbon gases to acidic water microjets through interface-sensitive mass spectrometry. By changing gas concentrations, H2O (D2O) solvent, bulk pH and comparing results from experiments on acyclic, cyclic, and aromatic compounds, we elucidated three competing reaction mechanisms: chain propagation (CP), chain transfer (CT), and hydride abstraction (HA). We found that conjugative π-electron delocalization in the carbocation is the most important factor for the interfacial oligomerization processes. Our results showed that electrophilic attack on C[double bond, length as m-dash]C double bonds (CP and CT) is limited, and that on C–H single bonds (HA) is enhanced for carbocations lacking conjugation, which is not the case in bulk organic solutions. Carbocationic oligomers generated by the encounter of gaseous unsaturated hydrocarbons and acidic water surfaces potentially contribute to the molecular complexity in atmospheric particles.

Graphical abstract: Chain-propagation, chain-transfer, and hydride-abstraction by cyclic carbocations on water surfaces

Back to tab navigation

Supplementary files

Publication details

The article was received on 06 Aug 2018, accepted on 12 Sep 2018 and first published on 12 Sep 2018


Article type: Paper
DOI: 10.1039/C8CP04993A
Citation: Phys. Chem. Chem. Phys., 2018,20, 25256-25267
  •   Request permissions

    Chain-propagation, chain-transfer, and hydride-abstraction by cyclic carbocations on water surfaces

    S. Ishizuka, A. Matsugi, T. Hama and S. Enami, Phys. Chem. Chem. Phys., 2018, 20, 25256
    DOI: 10.1039/C8CP04993A

Search articles by author

Spotlight

Advertisements