ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Photoinduced Rydberg ionization (PIRI) spectroscopy has been applied to the problem of recording vibrationally resolved spectra of the dipole-forbidden B˜ 2E2g←X˜ 2E1g transition of C6H6+ and C6D6+. PIRI spectra of the B˜ state have been recorded via a number of vibrational states of the ionic ground state. A combination of Herzberg–Teller and pseudo-Jahn–Teller vibronic coupling between the B˜ state and a close lying C˜ state were used to explain the complex B˜ state vibrational structure. The two pseudo-Jahn–Teller vibrational modes, ν16 and ν17, were both found to be active in the PIRI spectra. In addition, evidence for a strong pseudo-Jahn–Teller interaction within each of these modes was found. The perturbed vibronic bands resulting from this pseudo-Jahn–Teller activity were successfully modeled using a two-mode pseudo-Jahn–Teller vibronic coupling model. Using a combination of the spectral results and the pseudo-Jahn–Teller calculations, we were able to generate absolute vibronic symmetry assignments for many of the lower B˜ state vibrational levels, from which vibrational assignments were made. The calculations also produced unperturbed vibrational frequencies for both pseudo-Jahn–Teller active modes along with values for their respective linear coupling constants. © 1997 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.474526
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