ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Direct observation of the rotational fine structure levels of a vibrationally excited negative ion dipole-bound state (DBS) is reported. Autodetachment resonances of H2CCC− were observed for the 2A1−2B1 transition in one quanta of ν6, ν4, and ν2 and two quanta of ν6 vibrational modes of the DBS. Rotational assignments for both the electronic ground state and the DBS were performed. Strong type (a) Coriolis coupling between ν6 and ν9 in both the electronic ground and excited states was observed, and coupling constants were determined. QCISD ab initio calculations were performed for the ground state, the negative ion, and the neutral state of H2CCC. The calculations on the neutral agree well with measured vibrational frequencies of the dipole-bound state. The autodetachment resonances contain information about the detachment dynamics via the observed linewidths, showing, e.g., that motions along the dipole moment axis significantly enhance autodetachment, indicating that the DBS is unstable with respect to neutral core motion which modulates the magnitude value of the dipole moment. © 1996 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.472879
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