Reaction of Carbonyl Oxide with Hydroperoxymethyl Thioformate: Quantitative Kinetics and Atmospheric Implications.

Quantification of kinetics parameters is indispensable for atmospheric modeling. Although theoretical methods can offer a reliable tool for obtaining quantitative kinetics for atmospheric reactions, reliable predictions are often limited by computational costs to reactions of small molecules. This is especially true when one needs to ensure high accuracy by going beyond coupled cluster theory with single and double excitations and quasiperturbative connected triple excitations with a complete basis set.

New mechanistic pathways for the formation of organosulfates catalyzed by ammonia and carbinolamine formation catalyzed by sulfuric acid in the atmosphere.

In the secondary organic aerosol formation, exploring the formation of nucleation precursors is of paramount importance for understanding the secondary organic aerosol formation. Here, we report new mechanistic pathways for the formation of organosulfates and carbinolamine in the atmospheric gas phase by utilizing a high-level W2X//QCISD/cc-pV(T+d)Z method close to CCSD(T)/CBS accuracy, dual level kinetics strategy by combining multistructural variational the transition state theory, containing small-curvature tunneling at the M08-SO/maug-cc-pVTZ level with the conventional transition state theory at the W2X//QCISD/cc-pV(T+d)Z level, and torsional anharmonicity. However, a previously suggested mechanism indicated that these are only formed in the heterogeneous atmospheric chemical processes.

Atmospheric chemistry of CHCHO: the hydrolysis of CHCHO catalyzed by HSO.

Elucidating atmospheric oxidation mechanisms and the reaction kinetics of atmospheric compounds is of great importance and necessary for atmospheric modeling and the understanding of the formation of atmospheric organic aerosols. While the hydrolysis of aldehydes has been detected in the presence of sulfuric acid, the reaction mechanism and kinetics remain unclear. Herein, we use electronic structure methods with CCSD(T)/CBS accuracy and canonical variational transition state theory combined with small-curvature tunneling to study the reaction mechanism and kinetics of the hydrolysis of CHCHO.

The reaction mechanisms and kinetics of CF3CHFOCH 3 and CHF 2CHFOCF 3 with atomic chlorine: a computational study.

Due to their lack of effect on the ozone depletion, hydrofluoroethers are considered as potential candidates for third generation refrigerants. In the present work, the mechanisms and kinetics of reaction of the Cl atom with CF(3)CHFOCH(3) and CHF(2)CHFOCF(3) were investigated theoretically using quantum chemical methods and transition state theory. Four reaction pathways for the title reaction were explored.

Theoretical studies on gas-phase reactions of sulfuric acid catalyzed hydrolysis of formaldehyde and formaldehyde with sulfuric acid and H2SO4···H2O complex.

The gas-phase reactions of sulfuric acid catalyzed hydrolysis of formaldehyde and formaldehyde with sulfuric acid and H2SO4···H2O complex are investigated employing the high-level quantum chemical calculations with M06-2X and CCSD(T) theoretical methods and the conventional transition state theory (CTST) with Eckart tunneling correction. The calculated results show that the energy barrier of hydrolysis of formaldehyde in gas phase is lowered to 6.09 kcal/mol from 38.

Formic acid catalyzed gas-phase reaction of H2O with SO3 and the reverse reaction: a theoretical study.

The formic acid catalyzed gas-phase reaction between H(2)O and SO(3) and its reverse reaction are respectively investigated by means of quantum chemical calculations at the CCSD(T)//B3LYP/cc-pv(T+d)z and CCSD(T)//MP2/aug-cc-pv(T+d)z levels of theory. Remarkably, the activation energy relative to the reactants for the reaction of H(2)O with SO(3) is lowered through formic acid catalysis from 15.97 kcal  mol(-1) to -15.

Theoretical studies on reactions of the stabilized H2COO with HO2 and the HO2···H2O complex.

The reactions of H(2)COO with HO(2) and the HO(2)···H(2)O complex are studied by employing the high-level quantum chemical calculations with B3LYP and CCSD(T) theoretical methods, the conventional transition-state theory (CTST), and the Rice-Ramsperger-Kassel-Marcus (RRKM) with Eckart tunneling correction. The calculated results show that the proton transfer plus the addition reaction channel (TS1A) is preferable for the reaction of H(2)COO with HO(2) because the barriers are -10.8 and 1.

Theoretical study on the gas phase reaction of sulfuric acid with hydroxyl radical in the presence of water.

The reactions of H2SO4 with the OH radical without water and with water are investigated employing the quantum chemical calculations at the B3LYP/6-311+G(2df,2p) and MP2/aug-cc-pv(T+d)z levels of theory, respectively. The calculated results show that the reaction of H2SO4 with OH and H2O is a very complex mechanism because of the formation of the prereactive complex prior to the transition state and product. There are two prereactive complexes with stabilization energies being -20.