Anion-aromatic bonding: a case for anion recognition by pi-acidic rings.
The basis for unprecedented noncovalent bonding between anions and the aryl centroid of electron-deficient aromatic rings has been demonstrated by an ab initio study of the interaction between 1,3,5-triazine and the fluoride, chloride, and azide ion at the MP2 level of theory. Minima are also located corresponding to C[bond]H...X(-) hydrogen bonding, reactive complexes for nucleophilic attack on the triazine ring, and pi-stacking interactions (with azide). Trifluoro-1,3,5-triazine also participates in aryl centroid complexation and forms nucleophilic reactive complexes with anions. This novel mode of bonding suggests the development of new cyclophane-type receptors for the recognition of anions.
Mascal
Mark
M
Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, USA. mascal@chem.ucla.edu
Armstrong
Alan
A
Bartberger
Michael D
MD