Jump to main content
Jump to site search

Issue 16, 2018
Previous Article Next Article

Kinetics of the reaction of CO3˙(H2O)n, n = 0, 1, 2, with nitric acid, a key reaction in tropospheric negative ion chemistry

Author affiliations

Abstract

A significant fraction of nitrate in the troposphere is formed in the reactions of HNO3 with the carbonate radical anion CO3˙ and the mono- and dihydrated species CO3˙(H2O)1,2. A reaction mechanism was proposed in earlier flow reactor studies, which is investigated here in more detail by quantum chemical calculations and experimental reactivity studies of mass selected ions under ultra-high vacuum conditions. Bare CO3˙ forms NO3(OH˙) as well as NO3, with a total rate coefficient of 1.0 × 10−10 cm3 s−1. CO3˙(H2O) in addition affords stabilization of the NO3(HCO3˙) collision complex, and thermalized CO3˙(H2O) reacts with a total rate coefficient of 6.3 × 10−10 cm3 s−1. A second solvent molecule quenches the reaction, and only black-body radiation induced dissociation is observed for CO3˙(H2O)2, with an upper limit of 6.0 × 10−11 cm3 s−1 for any potential bimolecular reaction channel. The rate coefficients obtained under ultra-high vacuum conditions are smaller than in the earlier flow reactor studies, due to the absence of stabilizing collisions, which also has a strong effect on the product branching ratio. Quantum chemical calculations corroborate the mechanism proposed by Möhler and Arnold. The reaction proceeds through a proton-transferred NO3(HCO3˙) collision complex, which can rearrange to NO3(OH˙)(CO2). The weakly bound CO2 easily evaporates, followed by evaporation of the more strongly attached OH˙, if sufficient energy is available.

Graphical abstract: Kinetics of the reaction of CO3˙−(H2O)n, n = 0, 1, 2, with nitric acid, a key reaction in tropospheric negative ion chemistry

Back to tab navigation

Supplementary files

Publication details

The article was received on 17 Nov 2017, accepted on 19 Feb 2018 and first published on 20 Feb 2018


Article type: Paper
DOI: 10.1039/C7CP07773D
Citation: Phys. Chem. Chem. Phys., 2018,20, 10838-10845
  • Open access: Creative Commons BY license
  •   Request permissions

    Kinetics of the reaction of CO3˙(H2O)n, n = 0, 1, 2, with nitric acid, a key reaction in tropospheric negative ion chemistry

    C. van der Linde, W. K. Tang, C. Siu and M. K. Beyer, Phys. Chem. Chem. Phys., 2018, 20, 10838
    DOI: 10.1039/C7CP07773D

    This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material.

    Reproduced material should be attributed as follows:

    • For reproduction of material from NJC:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
    • For reproduction of material from PCCP:
      [Original citation] - Published by the PCCP Owner Societies.
    • For reproduction of material from PPS:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
    • For reproduction of material from all other RSC journals:
      [Original citation] - Published by The Royal Society of Chemistry.

    Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.

Search articles by author

Spotlight

Advertisements