Theoretical molecular structures for weakly bound complexes HX center dot center dot center dot center dot SO3 (X=F, Cl, Br): ab initio and DFT calculations

Abstract

The molecular structures of HX....SO3 (X = F, Cl, Br) have been calculated by ab initio and density functional theory (DFT) methods. Calculations show that they are weakly bound van der Waals complexes rather than genuine electron donor-acceptor complexes since they have long intermolecular distances. At the MP2/6-311++G(3df, 3p4) level, the intermolecular bond distances S....F, S....Cl, and S.... Br are computed to be 2.667, 3.112, and 3.230 Angstrom, respectively, while the angles <H-F-S, <H-Cl-S, and <H-Br-S are computed to be 108.4degrees, 87.4degrees, and 85.6degrees, respectively. (C) 2002 Published by Elsevier Science B.V.