Spectroscopy and dynamics of the dipole-supported state of acetyl fluoride enolate anion

High resolution photodetachment spectroscopy of acetyl fluoride enolate anion has revealed ≈200 narrow resonances near the photodetachment threshold, corresponding to excitation of the anion to a diffuse state in which the electron is weakly bound by the field of the molecular dipole. An analysis of the rotational transitions between the ground valence state and the excited dipole-supported state has been carried out, yielding spectroscopic constants for both states. The binding energy of the dipole-supported state is found to be less than 35 cm−1 . The dependence of autodetachment lifetimes upon rotational quantum numbers of the dipole-supported state has been measured. The selection rules and dynamics of autodetachment from the dipole-supported state are discussed. The results are compared with those obtained previously for acetaldehyde enolate anion.