Enthalpy formation of fluorene: Is a challenging problem for theory or experiment?

The large discrepancy between the experimental enthalpy of formation of fluorene and theoretical value calculated by G3(MP2) method was revealed more than ten years ago. Three years later, a new...

The π-π Stacking Interaction of Azaborine and Some of its Derivatives: A Quantum Mechanical Study

Derivatives of azaborine viz., diazaborines, borazine and pseudoborazine, but interestingly all of them are not purely aromatic. The sequence of aromaticity of some azaborine and its derivatives were given as azaborine > diazaborine > pesudoborazine > borazine. Also they have different ring bond distances as B-B, N-N and B-N. Due to their difference in properties of aromaticity and structure, the π-π stacking interaction was also very interesting and quite different from the normal aromatic systems. Quantum mechanical, MP2 method is quite useful for determining the π-π stacking interaction in different azaborine dimers and its derivatives for eclipsed and staggered stacked conformations. Stacked models of azaborine derivatives with intermolecular rotations also shows different interaction energies.

Anomalous description of the anharmonicity of bending motions of carbon–carbon double bonded molecules with the MP2 method: ethylene as a case study

In this work, we report anomalous descriptions of bending modes of the smallest carbon–carbon double bonded molecule ethylene with the MP2 method.