Sigma-hole bonding between like atoms; a fallacy of atomic charges.
Covalently bonded atoms, at least in Groups V-VII, may have regions of both positive and negative electrostatic potentials on their surfaces. The positive regions tend to be along the extensions of the bonds to these atoms; the origin of this can be explained in terms of the sigma-hole concept. It is thus possible for such an atom in one molecule to interact electrostatically with its counterpart in a second, identical molecule, forming a highly directional noncovalent bond. Several examples are presented and discussed. Such "like-like" interactions could not be understood in terms of atomic charges assigned by any of the usual procedures, which view a bonded atom as being entirely positive or negative.
Politzer
Peter
P
Department of Chemistry, University of New Orleans, New Orleans, LA 70148, USA. ppolitze@uno.edu
Murray
Jane S
JS
Concha
Monica C
MC
D004602:Elements; D008956:Models, Chemical; D055672:Static Electricity
D004602:Elements