On the formation of sandwich and multidecker complexes via π⋯π interaction: a DFT study†
Abstract
The stability of sandwich and multidecker complexes of benzene bridged via inorganic π-systems (N2/O2) was analyzed using density functional theory (DFT). Gas phase results confirmed the stability of such sandwich and multidecker complexes. The interaction energy of the complexes in the gas phase increases with the increase in size of the complexes. On the other hand, the average interaction energy decreases as the size of the complex increases. A solvent phase study also advocates the existence of the complexes in the solvent phase. The interaction is primarily dispersive and the process of complexation is exothermic in nature. NBO and IR analysis confirmed the direction of charge transfer from the benzene ring to the antibonding π-orbital of N2/O2 upon complexation. TD-DFT calculations showed a red shift in the absorption maxima (to the visible range for the O2-complexes) upon complexation.