The electrostatic interactions in van der Waals complexes involving aromatic molecules

Abstract

The minima in the electrostatic energy, for accessible orientations, have been located for the s‐tetrazine and benzene dimers and the 1:1 complexes of s‐tetrazine with hydrogen chloride, water, acetylene, and benzene, and of benzene with acetylene, anthracene, and perylene. The minima give reasonably successful predictions of the structures of these van der Waals molecules, demonstrating the importance of the electrostatic interactions in these systems. The electrostatic energy was calculated using sets of distributed multipoles obtained from ab initio wave functions of the monomers. This method is contrasted with empirical point charge and central multipole models for the electrostatic energy. It is shown that the simple models for the electrostatic interactions can give qualitatively misleading results for aromatic systems.