Dipole-bound anions supported by charge–transfer interaction: Anionic states of H_nF_3−nN → BH₃ and H₃N → BH_nF_3−n (n = 0, 1, 2, 3)

The possibility of electron binding to five molecules (i.e., F₃N → BH₃, H₂FN → BH₃, HF₂N → BH₃, H₃N → BH₂F, H₃N → BHF₂) was studied at the coupled cluster level of theory with single, double, and noniterative triple excitations and compared to earlier results for H₃N → BH₃ and H₃N → BF₃. All these neutral complexes involve dative bonds that are responsible for significant polarization of these species that generates large dipole moments. As a consequence, all of the neutral systems studied, except F₃N → BH₃, support electronically stable dipole-bound anionic states whose calculated vertical electron detachment energies are 648 cm⁻¹ ([H₂FN → BH₃]⁻), 234 cm⁻¹ ([HF₂N → BH₃]⁻), 1207 cm⁻¹ ([H₃N → BH₂F]⁻), and 1484 cm⁻¹ ([H₃N → BHF₂]⁻). In addition, we present numerical results for a model designed to mimic charge–transfer (CT) and show that the electron binding energy correlates with the magnitude of the charge flow in the CT complex. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003