Intramolecular vibrational redistribution of energy in the stimulated emission pumping spectrum of acetylene

Journal Article · Mon Nov 15 04:00:00 EST 1993 · Journal of Chemical Physics; (United States)

DOI:https://doi.org/10.1063/1.465716· OSTI ID:5914571

Jonas, D M; Solina, S A.B.; Rajaram, B; Silbey, R J; Field, R W ^[1]; Yamanouchi, K; Tsuchiya, S ^[2]

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1. Department of Chemistry and George R. Harrison Spectroscopy Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
2. Department of Pure and Applied Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153 (Japan)

Using a combination of low resolution dispersed [ital [tilde A]][r arrow][ital [tilde X]] fluorescence spectra and high resolution stimulated emission pumping, we have spectroscopically identified the first stages of vibrational energy flow in the highly vibrationally excited acetylene prepared by [ital [tilde A]][r arrow][ital [tilde X]] emission over the energy range 5 000--18 000 cm[sup [minus]1]. A detailed study of the stimulated emission pumping (SEP) spectrum of acetylene in the [ital E][sub VIB]=7000 cm[sup [minus]1] region, in which we report spectroscopic constants and rovibrational term values for 12 vibrational levels, has conclusively shown that Darling--Dennison resonance between the [ital cis] and [ital trans] degenerate bending vibrations is the first step in the redistribution of vibrational energy from the initially excited Franck--Condon bright CC stretch and [ital trans]-bend vibrational combination levels. This allows an extension of our prior dispersed fluorescence (DF) assignments which suggested the crucial role of Darling--Dennison coupling between the [ital cis] and [ital trans] bends in IVR [J. Chem. Phys. [bold 95], 6336 (1991)].

• DOE Contract Number: FG02-87ER13671
• OSTI ID: 5914571
• Journal Information: Journal of Chemical Physics; (United States), Journal Name: Journal of Chemical Physics; (United States) Vol. 99:10; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

664200* -- Spectra of Atoms & Molecules & their Interactions with Photons-- (1992-)
664400 -- Experimentally Derived Information on Atomic & Molecular Properties-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
ACETYLENE
ALKYNES
EMISSION
ENERGY LEVELS
ENERGY SPECTRA
ENERGY-LEVEL TRANSITIONS
EXCITED STATES
FERMI RESONANCE
FLUORESCENCE
FRANCK-CONDON PRINCIPLE
HYDROCARBONS
INTERATOMIC FORCES
LUMINESCENCE
OPTICAL PUMPING
ORGANIC COMPOUNDS
PUMPING
RESOLUTION
RESONANCE
SPECTRA
STIMULATED EMISSION
VIBRATIONAL STATES