Journal of Physical Organic Chemistry

The electronic structure of Aristolochic acid (AA1) has been elucidated using the aug-cc-pVDZ level of theory, resulting in a potentially trapped resonance at the ring A which causes a localized electronic distribution, differentiating the first from the two other rings of the phenanthrene moiety of AA1. This property can play a significant role in its transformation pathways in biochemical and toxicological settings.

Altan–corannulene was designed to hold a strong paratropic current. Computations of excitation energies, magnetizabilities, and current strengths for its dianion, tetraanion, and hexaanion show different numbers of counter-rotating currents. The hexaanion in the figure has a diatropic/paratropic/diatropic pattern, the ‘mirror-image’ of that of the neutral species. Magnetizability and excitation energy suggest that the hexaanion should be an aromatic molecule. Interpretation of the current density patterns within the ipsocentric approach, as well as comparison with fullerene cages, is reported.

The mechanism of sulfurization of substituted triphenylphosphines with 4-(3- and 4-substituted)-1,2,4-dithiazolidine-3,5-diones in acetonitrile, dichloromethane, tetrahydrofuran and toluene at 25 °C was studied. The reaction pathway involves rate-limiting initial nucleophilic attack of the phosphorus at sulfur followed by fast decomposition of the phosphonium intermediate to the corresponding phosphine sulfide, phenylisocyanate and carbonylsulfide. The transition-state structure is very polar and resembles the zwitter-ionic phosphonium intermediate.

For the first time, modified NH₂ groups (N-acylated, N-alkylated, N,N′-bridged, N-heterocyclic, and N-deprotonated) were ranged with regard to their electron-donating ability from the naphthalene peri-positions to the conjugated NO₂ groups in dimethyl sulfoxide solution and in the solid state.

The estimation of the activation energy of the trimerization of ethyne to form benzene by ab initio molecular orbital and density functional methods depended on the calculation levels. Here, we proposed the more accurate estimation of the activation energy and reaction path with the relation between the activation energy and interaction energy.