Heat of formation of the HOSO(2) radical from accurate quantum chemical calculations

Wim Klopper*, David P. Tew, Nuria Gonzalez-Garcia, Matthias Olzmann

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

16 Citations (Scopus)

Abstract

The reaction HOSO(2)+O(2)-> HO(2)+SO(3) (2) is of crucial importance for sulfuric acid formation in the atmosphere, and reliable thermochemical data are required for an adequate modeling. The currently least well known thermochemical quantity of reaction (2) is the enthalpy of formation of the hydroxysulfonyl radical (HOSO(2)). We report on high-level quantum chemical calculations to predict the binding energy of the HO-SO(2) bond and deduce a value for the enthalpy of formation of HOSO(2) using the most reliable thermodynamic data of OH and SO(2). On the basis of anharmonic vibrational frequencies from calculations at the fc-CCSD(T)/cc-pV(T+d)Z level of theory, the enthalpy of reaction at 0 K for the reaction OH+SO(2). HOSO(2) (1) was computed to be Delta(R)H(0) (K)(1)=-109.4 +/- 2.0 kJ/mol and the thermal corrections result in Delta(R)H(298) (K)(1)=-114.7 +/- 3.0 kJ/mol. From these values, we obtain Delta(f)H(0) (K)(HOSO(2))=-366.6 +/- 2.5 and Delta(f)H(298) (K)(HOSO(2))=-374.1 +/- 3.0kJ/mol, respectively. Accordingly, Delta(R)H(298) (K)(2)=-8.5 +/- 3.0 and Delta(R)H(298) (K)(2)=-9.5 +/- 3.0kJ/mol. (c) 2008 American Institute of Physics. [DOI: 10.1063/1.2973637]

Original languageEnglish
Article number114308
Number of pages7
JournalJournal of Chemical Physics
Volume129
Issue number11
DOIs
Publication statusPublished - 21 Sep 2008

Keywords

  • CORRELATED MOLECULAR CALCULATIONS
  • CONSISTENT BASIS-SETS
  • GAUSSIAN-BASIS SETS
  • COUPLED-CLUSTER METHODS
  • PERTURBATION-THEORY
  • GAS-PHASE
  • ENERGY CALCULATIONS
  • ATOMS ALUMINUM
  • HARTREE-FOCK
  • CORE-VALENCE

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