A Computational Study on the Stacking Interaction in Quinhydrone

The stability and electron density topology of quinhydrone complex was studied using multiple computational levels, including MPW1B95 Truhlar's density functional. The QTAIM analysis demonstrates that an electron population transfer from hydroquinone to quinone monomer accompanies the complex formation. The variations undergone by atomic populations indicate that the electron transfer through HOMO LUMO overlap is combined with a reorganization of the electron density within each monomer. Variations of two- and six-center delocalization indices show a small reduction of electron delocalization in the hydroquinone ring upon complex formation.