Theoretical study on the noncovalent interactions involving triplet diphenylcarbene

Abstract

The properties of some types of noncovalent interactions formed by triplet diphenylcarbene (DPC 3 ) have been investigated by means of density functional theory (DFT) calculations and quantum theory of atoms in molecules (QTAIM) studies. The DPC 3 •••LA (LA = AlF 3 , SiF 4 , PF 5 , SF 2 , ClF) complexes have been analyzed from their equilibrium geometries, binding energies, charge transfer and properties of electron density. The triel bond in the DPC 3 •••AlF 3 complex exhibits a partially covalent nature, with the binding energy − 65.7kJ/mol. The tetrel bond, pnicogen bond, chalcogen bond and halogen bond in the DPC 3 •••LA (LA = SiF 4 , PF 5 , SF 2 , ClF) complexes show the character of a weak closed-shell noncovalent interaction.Polarization plays an important role in the formation of the studied complexes. The strength of intermolecular interaction decreases in the order LA = AlF 3 > ClF > SF 2 > SiF 4 > PF 5 . In the process of complexation, the charge transferrs from DPC 3 to the antibonding orbital of AlF 3 /SF 2 /ClF, the quantity of charge transfer is very small between DPC 3 and SiF 4 /PF 5 . The electron spin density transferrs from the radical DPC 3 to ClF and SF 2 in the formation of halogen bond and chalcogen bond, but for the DPC 3 •••AlF 3 /SiF 4 /PF 5 complexes, the transfer of electron spin density is minimal.