Dative versus electron-sharing bonding in the isoelectronic argon compounds ArR+ (R = CH3, NH2, OH, and F)

Abstract

A computational investigation of the isoelectronic ArR⁺ (R = CH₃, NH₂, OH, and F) species has been performed. The ground states of all four complexes are determined to be the lowest singlet isomers. A range of state-of-the-art quantum chemistry methods have been utilized to systematically examine the Ar–E bonds (E = C, N, O, and F) in these Ar-containing complexes, which could be categorized to be of covalent type with a gradual increase in the covalent character along C to F. Moreover, the nature of the Ar–E bond roughly depends on the ionization potential difference between the Ar atom and R radical, except for ArOH⁺. The dative Ar → R⁺ bond is found for both ArCH₃⁺ and ArNH₂⁺ complexes, whereas the Ar–E bonds in both ArOH⁺ and ArF⁺ are better described as electron-sharing Ar⁺–R bonds.