Daly, SM orcid.org/0000-0003-3648-6893, Bones, DL orcid.org/0000-0003-1394-023X and Plane, JMC (2019) A Study of the reactions of Al⁺ ions with O₃, N₂, O₂, CO₂ and H₂O: influence on Al⁺ chemistry in planetary ionospheres. Physical Chemistry Chemical Physics, 21 (26). pp. 14080-14089. ISSN 1463-9076
Abstract
The reactions between Al+(31S) and O3, O2, N2, CO2 and H2O were studied using the pulsed laser ablation at 532 nm of an aluminium metal target in a fast flow tube, with mass spectrometric detection of Al+ and AlO+. The rate coefficient for the reaction of Al+ with O3 is k(293 K) = (1.4 ± 0.1) × 10−9 cm3 molecule−1 s−1; the reaction proceeds at the ion–dipole enhanced Langevin capture frequency with a predicted T−0.16 dependence. For the recombination reactions, electronic structure theory calculations were combined with Rice–Ramsperger–Kassel–Markus theory to extrapolate the measured rate coefficients to the temperature and pressure conditions of planetary ionospheres. The following low-pressure limiting rate coefficients were obtained for T = 120–400 K and He bath gas (in cm6 molecule−2 s−1, uncertainty ±σ at 180 K): log10(k, Al+ + N2) = −27.9739 + 0.05036 log10(T) − 0.60987(log10(T))2, σ = 12%; log10(k, Al+ + CO2) = −33.6387 + 7.0522 log10(T) − 2.1467(log10(T))2, σ =13%; log10(k, Al+ + H2O) = −24.7835 + 0.018833 log10(T) − 0.6436(log10(T))2, σ = 27%. The Al+ + O2 reaction was not observed, consistent with a D°(Al+–O2) bond strength of only 12 kJ mol−1. Two reactions of AlO+ were also studied: k(AlO+ + O3, 293 K) = (1.3 ± 0.6) × 10−9 cm3 molecule−1 s−1, with (63 ± 9)% forming Al+ as opposed to OAlO+; and k(AlO+ + H2O, 293 K) = (9 ± 4) × 10−10 cm3 molecule−1 s−1. The chemistry of Al+ in the ionospheres of Earth and Mars is then discussed.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | This journal is © the Owner Societies 2019. This is an author produced version of a paper published in Physical Chemistry Chemical Physics. Uploaded in accordance with the publisher's self-archiving policy. |
Dates: |
|
Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemistry (Leeds) > Physical Chemistry (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 21 Jan 2019 15:50 |
Last Modified: | 18 Jan 2020 01:39 |
Status: | Published |
Publisher: | Royal Society of Chemistry |
Identification Number: | 10.1039/C8CP07572G |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:141241 |