A theoretical prediction on intermolecular monoelectron dihydrogen bond H⋯e⋯H in the cluster anion (FH)2{e}(HF)2

Abstract

Using the aug-cc-pVDZ basis set supplemented with bond functions (BF), the existences of the systems (FH)2{e}(HF)2 have been studied. It was found to have equilibrium geometry with all frequencies real at the second-order Møller–Plesset perturbation (MP2/aug-cc-pvdz+BF) level. The calculated vertical electron detachment energy is 1.065 eV for (FH)2{e}(HF)2 at the coupled cluster level of theory with single, double, and noniterative triple excitations (CCSD(T)). The result calculated indicated that the stabilities of the system own to forming the monoelectron dihydrogen bond H⋯e⋯H, which comes not only from the static Coulomb interaction but also from the dispersion interaction between the loosely bound (excess) electron and the neutral molecular (cluster’s) hosts. The characteristics of the monoelectron dihydrogen bond H⋯e⋯H of the system have been revealed. The H⋯e⋯H bond length is 2.359 Å for (FH)2{e}(HF)2. Some vibrational modes that display the presence of the bond H⋯e⋯H have been found and a novel secondary interaction, H-bond-excess electron attracting has been discussed.