Inorganic benzenes as the noncovalent interaction donor: a study of the π-hole interactions.

For inorganic benzenes C3N3X3 and B3O3X3 (X = H, F, CN), the positive electrostatic potentials (π-hole) were discovered above and below the inorganic benzene ring center. Then, the π-hole interactions between the inorganic benzenes and NCH have been designed and investigated by MP2/aug-cc-pVDZ calculations. In this paper, the termolecular complexes B3O3X3···NCH···NCH, C3N3X3···NCH···NCH (X = H, F, CN) were also designed to illustrate the enhancing effects of the H···N hydrogen bond on the π-hole interactions. The π-hole interaction energy was influenced by the strength of different electron-withdrawing substituents of inorganic benzenes, gradually increasing in the order of X = H, F, CN. What's more, the π electron densities account for 71~88% of the total electron densities, indicating the strength of interaction energy is mainly determined by π-type electron densities. Graphical abstract The termolecular complexes B3O3X3···NCH···NCH, C3N3X3···NCH···NCH (X = H, F, CN) were designed to illustrate the enhancing effects of the H···N hydrogen bond on the π-hole interactions.