DFT and QTAIM study of the tetra-tert-butyltetraoxa[8]circulene regioisomers structure

► Tetra-tert-butyltetraoxa[8]circulene regioisomers were studied by DFT method. ► Electronic density distribution was calculated by the QTAIM method. ► The presence of stabilizing non-valence bonds is detected by X-ray experiment. ► The H⋯H contacts are dynamically unstable due to high ellipticity. ► The energy of the H⋯H and CH⋯O contacts was estimated by the Espinosa equation.