Density functional investigation of atmospheric sulfur chemistry. I. Enthalpy of formation of HSO and related molecules

Abstract

The enthalpy of formation of several species intervening in the atmospheric chemistry of sulfur compounds (SH, H2S, SO, HSO, SOH) have been calculated using density functional theory with correlation consistent basis sets and extrapolation to the complete basis set limit. Excellent agreement with experiment is found for the species of which the enthalpy of formation are well determined. The values predicted for HSO [ΔfH°298K(HSO)=−27.8±2.1 kJ/mol] and SOH [ΔfH°298K(SOH)=−6.8±2.1 kJ/mol] agree well with previous multireference configuration interaction (MR‐CI) calculations. Based on these results, it is determined that the reaction of HSO with ozone is endothermic at all temperatures but spontaneous above 220 K because of entropic effects. Both the reactions of dissociation SOH→H+SO and isomerization HSO→SOH are studied in detail, and the transition states located. The results are also in agreement with the much more costly MR‐CI results. © 2000 John Wiley & Sons, Inc. Int J Quant Chem 80: 439–453, 2000

Theoretical study of the electronic and hyperfine structures of the HSO and SOH radicals

“…However, the preference for HSO is correctly predicted with the large 6-311++G(3df,3pd) basis set. This behavior with the increasing size of the basis set has been observed previously using higher-level ab initio methods in combination with extended basis sets and extrapolations to the CBS limit [11,17,19,20]. Thus, the DE e and DE 0 energy differences at the B3LYP/6-311++G(3df,3pd) level (2.75 and 4.50 kcal/ mol, respectively) are in reasonable agreement with the values obtained employing much more expensive calculations as B3LYP/aug-cc-pV(5+d)Z (3.23 and 4.98 kcal/mol) [20], CASSCF + 1 + 2/cc-pV5Z (2.60 and 4.20 kcal/mol) [11] and CCSD(T)/CBS limit (2.40 and 4.20 kcal/mol) [19].…”

“…However, after the work of Xantheas and Dunning [10,11] with multireference methods and correlation consistent basis sets of up to quintuple-f quality, it seems well-established that HSO is more stable than SOH. Further theoretical investigations of Espinosa [12], Essefar [13], Wilson [14], Goumri [15], Decker [16], Denis et al [17,18] and Wilson et al [19,20] confirmed the preference of the HSO isomer.…”

“…However, when the hydrogen atom is bonded to the oxygen atom in SOAH, the r(SO) and p p (SO) overlaps are notably reduced compared to those of the diatomic Table 1 Geometrical parameters (bond lengths in Å and bond angles in degrees) and relative energies (in kcal/mol) for the HSO [17]. e Ref.…”

“…The reported anisotropic hfcs correspond to the components of the anisotropic hyperfine tensors in the principal axes of the hyperfine tensor itself [32] and the in-plane directions (T xx and T yy ) of the principal axes of the anisotropic tensors of 1 H, 17 O and 33 S are represented in Fig. 1.…”

A theoretical study of TeOH in its electronic ground state

“…The HO 2 [1][2][3] and HOS/SOH [4][5][6][7] radicals are interesting to computational chemists due to their importance in various chemical processes, especially processes in the atmosphere. The present work reports theoretical calculations for a triatomic molecule of analogous electronic structure, TeOH.…”