## 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 language | English |
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Article number | 114308 |

Number of pages | 7 |

Journal | Journal of Chemical Physics |

Volume | 129 |

Issue number | 11 |

DOIs | |

Publication status | Published - 21 Sept 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