INTERMOLECULAR INTERACTIONS A FIVE MEMBERED RING PATTERN CONTAINING HALOGEN...HALOGEN AND HALOGEN...HYDROGEN INTERACTIONS. Oshrit Navon and Joel Bernstein, Department of Chemistry, Ben-Gurion University of the Negev, Beer Sheva 84105 Israel

In the course of a structural study on halogen-substituted benzylideneanilines we noted the presence of a five-membered ring pattern of the benzylideneanilines family[l].Of the six structures studied four are isostructural structures that contain this ring and exhibit an unusual planar molecular conformation, while the remaining two are not planar and do not contain this pattern. The pattern may be defined as an intermolecular ring containing five atoms with hal...hal, C-H...hal interactions:

Using the Cambridge Structural Database (CSD) we have identified and characterized this intermolecular pattern in many other structures.

We will present detailed results for the case where X, Y = Cl, Br on aromatic systems. In addition there is evidence that this pattern may persist over a much wider range of chemical functionality, and preliminary results on such patterns will also be presented.

1. Navon, O., Bernstein, J., Zamir, S., 60th Annual Meeting of the Israel Chemical Society, Weizmann Institute, Rehovot, Israel (1995).