Oxidation of HOSO˙ by Cl˙: a new source of SO2 in the atmosphere?

Amit Kumar; Subhasish Mallick; Pradeep Kumar

doi:10.1039/d1cp01048d

Oxidation of HOSO˙ by Cl˙: a new source of SO₂ in the atmosphere?

Phys Chem Chem Phys. 2021 Sep 14;23(34):18707-18711. doi: 10.1039/d1cp01048d. Epub 2021 Aug 19.

Authors

Amit Kumar¹, Subhasish Mallick, Pradeep Kumar

Affiliation

¹ Department of Chemistry, Malaviya National Institute of Technology Jaipur, Jaipur, 302017, India. pradeep.chy@mnit.ac.in.

PMID: 34612408
DOI: 10.1039/d1cp01048d

Abstract

In the present work, we have studied the formation of SO₂ in the atmosphere from the oxidation of HOSO˙ by Cl˙ at the CCSD(T)/aug-cc-pV(+d)TZ//MP2/aug-cc-pV(+d)TZ level of theory. The present work reveals that the title reaction is a barrierless reaction that proceeds through a stable intermediate sulfurochloridous acid having a stabilization energy of ∼-56.5 kcal mol^-1. The rate constant values within the temperature range of 213-400 K indicate that the rate of HOSO˙ + Cl˙ = SO₂ + HCl reaction does not change much with the change in temperature. Besides, the reaction was also found to be insensitive towards pressure change. Interestingly, the relative rate of HOSO˙ + Cl˙ reaction with respect to HOSO˙ + OH˙ reaction indicates that HOSO˙ + Cl˙ is always much slower than HOSO˙ + OH˙ reaction, within the temperature range of 213-400 K.