Marco Di Stefano

Experimental and theoretical investigation of the production of cations containing C-N bonds in the reaction of benzene with atomic nitrogen ions

In the last few years, astronomical spectra have revealed the presence of aromatic and polyaromatic molecules in extraterrestrial environments, near carbon stars, in molecular clouds and meteorites. Moreover, the recent observation of benzene in interstellar space has noticeably increased the interest in the entire class of molecules and in their chemical behavior. In this work, we have investigated the reaction between the benzene molecule and the atomic nitrogen cation and, in particular, the mechanisms by which the reactants are converted into cationic products containing at least one C–N bond, according to the general scheme C6H6+N+→HmCnN++CxHy. We have measured the energy dependence of the cross section in a guided ion beam tandem mass spectrometer. Relevant stationary points of the potential energy surface have been studied by using the density functional theory hybrid functional B3LYP with the 6-31G* basis set. Thermochemical calculations, and the comparison with experimental results, allow us to d...

Phenylium and naphtylium cations in the interstellar medium: a density functional study on their reactivity towards D 2 molecules

The reactions of the phenylium, C 6 H 5 +, and the naphtylium, C 10 H 7 +, cations with D 2 molecules are investigated at B3LYP/6-31G* level of theory. Our calculations indicate that the reactivity of C 6 H 5 + and C 10 H 7 + is dominated by the substitution of one or two hydrogen atoms with deuterium leading to isotope-exchange processes.

Theoretical investigations on the reactions of C 6 H 5 + and C 10 H 7 + with D 2

The recent discovery of benzene and polycyclic aromatic hydrocarbons (PAHs) in the interstellar clouds has increased the interest in this entire class of molecules, which result to be the object of several theoretical and experimental investigations. In this work, we have studied the reactions of the phenylium, C6H5+, and the naphtylium cation, C10H7+, with D2. All calculations have been carried out at B3LYP/6-31G* level of theory and they suggest that the addition products, C6H5D2+ and C10H7D2+, once formed, can be stabilized by unreactive collisions or lose a neutral molecule (H2 or HD) or an atom (H or D), respectively.

C 6 NH 6 + Ions as Intermediates in the Reaction between Benzene and N + Ions

The nitrenium ions of formula C6NH6 + arising from the reaction between benzene molecules and atomic nitrogen ions, N + (3P), are studied by means of theoretical methods so that their structures and relative stabilities are investigated. All calculations are carried out by using the DFT hybrid functional B3LYP in conjunction with the split valence 6-31G* basis set.