AB-INITIO STUDY OF THE COMPLEXATION OF BENZENE WITH AMMONIUM CATIONS

Complexes of benzene with ammonium cations (Me(n)H(4-n)N+ for n = 0-4) were studied using ab initio calculations with electron correlation i ncluded. The most stable structures and binding energies of the comple xes are reported. The calculated binding energies are in good agreemen t with experiment. Two types of NH-aromatic pi and CH-aromatic pi inte ractions, which are important in biological systems, are responsible f or the binding. From analysis of the structures and energies, the pi-s igma through-space interactions are seen to be significant in both ty pes of NH-pi and CH-pi interactions.