Do Surfaces of Positive Electrostatic Potential on Different Halogen Derivatives in Molecules Attract? Like Attracting Like!

Coulomb's law states that like charges repel, and unlike charges attract. However, it has recently been theoretically revealed that two similarly charged conducting spheres will almost always attract each other when both are in close proximity. Using multiscale first principles calculations, we illustrate practical examples of several intermolecular complexes that are formed by the consequences of attraction between positive atomic sites of similar or dissimilar electrostatic surface potential on interacting molecules. The results of the quantum theory of atoms in molecules and symmetry adapted perturbation theory support the attraction between the positive sites, characterizing the F center dot center dot center dot X (X=F, Cl, Br) intermolecular interactions in a series of 20 binary complexes as closed-shell type, although the molecular electrostatic surface potential approach does not (a failure!). Dispersion that has an r(-6) dependence, where r is the equilibrium distance of separation, is found to be the sole driving force pushing the two positive sites to attract. (C) 2017 Wiley Periodicals, Inc.