Ab initio determination of the C6H6•••CS2 cluster stabilization energy

The benzene-carbon disulfide 1:1 complex has been investigated by means of ab initio methods. The electronic structure and the relative orientational molecular preferences in this system could be determined. The complex geometry was optimized using a DZ2P basis set (double 5 plus double polarization basis). Energy corrections for electronic correlation using the second-order Moller-Plesset perturbation theory (MP2) as well as for the basis set superposition error (BSSE) were applied. Calculations conduced to four minimum energy configurations between that proposed initially. The T-shaped structure, where the C-infinity rotation axis coincides with the benzene C-6-axis, and the sandwich one, where the CS2 is slipped over the benzene C-2-axis, passing between a C-C benzene bond were the most stable. The stabilization energy for these cofigurations was determined to be 0.519 and 0.541 kcal/mol, respectively. The results indicate the existence of weakly bound complexes between benzene and carbon disulfide for all the structures studied. (C) 2000 Elsevier Science B.V. All rights reserved.