Fig. 1: Energy diagram for direct photodetachment and autodetachment via a dipole-bound state (DBS) of the FNH3− anion to the neutral F + NH3 → HF + NH2 reactive PES.
From: Probing the activated complex of the F + NH3 reaction via a dipole-bound state
The upper bold curve represents the minimum energy path of the F + NH3 reaction, connecting the reactants and products in their ground vibrational states. Three black curves sketched above it are neutral vibrational adiabatic potentials for the excited HF stretching mode (νHF = 1–3), and a red curve is for the dipole-bound state (DBS) of FNH3− anion with νHF = 1. The molecular orbital of the DBS is schematically plotted on a molecular structure next to the curve. Purple and light blue represent their different phases. The lower thick curve represents the anion PES. Structures around these curves are illustrated for the anion and the neutral reactant complex (RC), product complex (PC), and transition state (TS) in gray (H), dark blue (N), and light blue (F). The autodetachment of the DBS provides a bridge to access regions that are difficult to probe using the direct photodetachment, mainly due to the larger geometric difference between the anion and the neutral complex with νHF = 0. Energies shown in parentheses (in cm−1) are zero-point energy corrected and are relative to the reactant asymptote.
