Knowledge Bank

The structure and dynamics of the gas phase $CCCH2-$ ion are investigated by high resolution photodetachment spectroscopy using a coaxial laser-ion beam spectrometer. In particular, this molecule supports the unique short-lived excited states in which the electron is weakly bound through its interaction with the large dipole moment of the neutral core (dipole bound states). More than 5000 rovibrational transitions were observed and assigned to provide structural information about both the negative ion ground state and the neutral core as well as vibrationally excited states. Examination of the rotational and vibrational state dependencies of the autodetachment linewidths provides dynamical information regarding the detachment process. These linewidths reflect the coupling of the vibrational and rotational degrees of freedom to the weakly bound electron.