Theoretical Study of an Authentic Hydrocarbon Ion Pair.

For many years researchers believed that hydrocarbons only contain covalent bonds. However, since 1985 Okamoto et al. demonstrated the formation of hydrocarbon salts in several systems, demolishing the structural principle that hydrocarbons only contain covalent bonds.

Acid Enriched with Methanol: Formation of a Prebiotic Cluster in the Interstellar Medium.

Organic molecules are a potential source of prebiotic chemistry in the interstellar medium (ISM). Methanol (MetOH) is a very important source of more complex molecules. H O (aq) and Cl (aq) are fundamental to living organisms and can be generated in the ISM from the dissociation of HCl with just four water molecules, yielding the (H O) (H O) Cl ion-pair.

Photochemistry of Monohydrated Chloromethane: Formation of Free and Hydrated Cl and CH Ions from a Solvent-Shared Semi-Ion-Pair.

The effect of water molecule on the excited states of CHCl(HO), as compared to those of the isolated chloromethane, has been studied at the multireference configuration interaction with singles and doubles (MR-CISD), including extensivity corrections. Eight new Rydberg states are due to the water molecule but the common states of both systems are not severely altered. Potential energy curves of 23 singlet states along the C-Cl coordinate have also been computed at the MR-CISD level.

Competition between electron transfer and base-induced elimination mechanisms in the gas-phase reactions of superoxide with alkyl hydroperoxides.

Understanding the mechanism responsible for peroxides decomposition is essential to explain several biochemical processes. The mechanisms of the intrinsic reactions between the superoxide radical anion (O2˙-) and methyl, ethyl, and tert-butyl hydroperoxides (ROOH, with R = Me, Et, and t-Bu) have been characterized to understand the mechanism responsible for peroxides decomposition. The reaction energy diagrams suggest a competition between the spin-allowed and spin-forbidden electron transfer (ET), and base-induced elimination (ECO2) mechanisms.

Spin-Forbidden Branching in the Mechanism of the Intrinsic Haber-Weiss Reaction.

The mechanism of the O and HO reaction (Haber-Weiss) under solvent-free conditions has been characterized at the DFT and CCSD(T) level of theory to account for the ease of this reaction in the gas phase and the formation of two different set of products (Blanksby et al., . , , 4948).

Photochemistry of CH3Cl: Dissociation and CH···Cl Hydrogen Bond Formation.

State-of-the-art electronic structure calculations (MR-CISD) are used to map five different dissociation channels of CH3Cl along the C-Cl coordinate: (i) CH3(X̃(2)A2″) + Cl((2)P), (ii) CH3(3s(2)A1') + Cl((2)P), (iii) CH3(+)((1)A1') + Cl(-)((1)S), (iv) CH3(3p(2)E') + Cl((2)P), and (v) CH3(3p(2)A2″) + Cl((2)P). By the first time these latter four dissociation channels, accessible upon VUV absorption, are described. The corresponding dissociation limits, obtained at the MR-CISD+Q level, are 3.