High resolution photoelectron spectroscopy and femtosecond intramolecular dynamics of H[sub 2]CCO[sup +] and D[sub 2]CCO[sup +]

Journal Article · Sun Aug 15 00:00:00 EDT 1993 · Journal of Chemical Physics; (United States)

DOI:https://doi.org/10.1063/1.465215· OSTI ID:6325500

Niu, B; Bai, Y; Shirley, D A ^[1]

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1. Department of Chemistry, The University of California at Berkeley, Chemical Science Division, Lawrence Berkeley Laboratory, One Cyclotron Road, Berkeley, California 94720 (United States)

High resolution helium I[alpha] (584 A) photoelectron spectra of H[sub 2]CCO and D[sub 2]CCO are reported. The present spectra of the ground states of ketene cations show more vibrational fine structure than previously reported. The adiabatic ionization energies (AIEs) of the cations' first, second, and fifth excited states are determined unambiguously. The doubletlike fine structures present in the first excited states of ketene cations imply the excitation of a soft'' mode that was not observed before. It was assigned to the [nu][sub 5] mode, which is characterized by the CH[sub 2] (CD[sub 2]) group out-of-plane wagging motion. The complexity of the photoelectron spectra obtained for the ionic first excited states is attributed to the possible dissociation and predissociation of this state. Strong isotope effects are observed in the vibronic (vibrational) couplings in most of the ionic states. Vibrational autocorrelation functions are calculated from the high-resolution photoelectron spectra for four of the six ionic states observed. The dynamics of the ground states of the cations are characterized by a wave packet oscillating with small amplitude around the minimum of the upper potential energy surfaces (PES). The decay dynamics of the ionic first and fifth excited states of ketene are characterized by ultrafast intramolecular processes such as dissociation and predissociation.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6325500
• Journal Information: Journal of Chemical Physics; (United States), Vol. 99:4; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
CATIONS
PHOTOELECTRON SPECTROSCOPY
VIBRATIONAL STATES
KETENES
CORRELATION FUNCTIONS
DEUTERIUM COMPOUNDS
DISSOCIATION
FINE STRUCTURE
GROUND STATES
MOLECULES
PREDISSOCIATION
RESOLUTION
TIME RESOLUTION
CHARGED PARTICLES
ELECTRON SPECTROSCOPY
ENERGY LEVELS
EXCITED STATES
FUNCTIONS
HYDROGEN COMPOUNDS
IONS
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
SPECTROSCOPY
TIMING PROPERTIES
664400* - Experimentally Derived Information on Atomic & Molecular Properties- (1992-)