Theoretical models for solvation and catalysis in carbonyl addition

Methanediol decomposition mechanisms: A study considering various ab initio approaches

“…Involvement of the perturbation treatment in the MP2/6-31G** method enhances the stabilization to 10.1 or 9.7 kcal/mol with or without the ZPE corrections, respectively. The semiempirical PM3 method somewhat underestimates the effect (3.4 kcal/mol) similarly as in the mentioned use [4] of the simple ab initio HF/STO-3G calculations (5.2 kcal/mol).…”

“…The calculated reaction barrier is increasing in the order of HF/3-21G, HF/6-31G, and HF/6-31G** methods in the order 26.8, 40.2, and 49.6 kcal/mol [4] for the reverse transformation. The endothermic reaction energies shown in Table IV are of the values from 8.3 to 13.5 kcal/mol for all our ab initio and P M~ calculations, but these energies are decreasing by 2.6-3.1 kcal/mol after the ZPE corrections, and our best MP2/6-31C** value (6.1 kcal/mol) is much lower than the reported [4] uncorrected HF/STO-~G value (39.3 kcal/mol).…”

Understanding the catalytic role of oxalic acid in the SO<sub>3</sub> hydration to form H<sub>2</sub>SO<sub>4</sub> in the atmosphere

“…et al, 2001;Cameron et al, 2002;Steckler et al, 1997;Atkinson et al, 2006). Some addition (Steudel, 1995;Williams et al, 1983;Courmier et al, 2005;Zhang and Zhang, 2002), decomposition (Rayez et al, 2002;Kumar and Francisco, 2015;Gutbrod et al, 1996), isomerization (Zheng and Truhlar, 2010;Atkinson, 2007), and abstraction reactions (Ji et al, 2013;Ji et al, 2017) also are the important HAT reaction in the atmosphere. These atmospheric HAT reactions have a main feature that two-point hydrogen bond can occur and can facilitate hydrogen atom transfer (Kumar et al, 2016).…”

Spontaneous hydrolysis of ethyl formate: Isobaric activation parameters

“…These kinetic features suggest transition state (TS) structures in which many solvent molecules are immobilized and subjected to electrostriction associated with the solvation of developing charges and the trans- There is experimental [16,18] and theoretical [21,22] basis to consider a cyclic atomic array made of one RCO-X molecule and three water molecules, as a more complete picture of the TS complex. Esters of formic acid also undergo neutral hydrolysis, at faster rates compared with the corresponding acetates.…”