A computational analysis of non-covalent interactions between aromatic compounds

A computational study was conducted to determine the most stable configuration geometry, and to evaluate the stabilization energy in the interaction between different test aromatic compounds. Dimers of benzene, naphthalene, anthracene, and, one trimer comprised of two benzene molecules and one molecule of naphthalene, were the subjects of the study. Gaussian 09 quantum chemistry suite ab initio calculations were performed by using MP2 method and the basis set G-311G**. The exponent for the polarized d orbital of carbon α d(C) was given the value 0.8200. Such value was obtained from the benzene dimer optimization with very similar results as those reported from the CCSD(T) method. This methodology was implemented for evaluating the stabilization energy trend with increasing number of aromatic rings in the interacting molecules. Among all the cases studied the energy minimum was obtained for the one having the conformation of displaced parallel molecules. This result seems to indicate that it is also possibly to obtain such stable conformation in the case of more complex aromatic systems of the same sort as the one considered here.