Characterization of the first excited [sup 1][Pi][sub 1] and the ground [ital X] [sup 1][Sigma][sup +] states of MgXe. I. Analysis of the [sup 1][Pi][sub 1][l arrow][ital X] [sup 1][Sigma][sup +] bound--bound transitions

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

DOI:https://doi.org/10.1063/1.465482· OSTI ID:5574169

McCaffrey, J G ^[1]; Funk, D J ^[2]; Breckenridge, W H ^[3]

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1. Department of Chemistry, St. Patrick's College, Maynooth, Co. Kildare (Ireland)
2. Los Alamos National Laboratory, Group CLS-4, M/S J567, Los Alamos, New Mexico 87545 (United States)
3. Department of Chemistry, University of Utah, Salt Lake City, Utah 84112 (United States)

Laser induced fluorescence (LIF) excitation spectra recorded for the vibrational bands in the Mg(3[ital s]3[ital p] [sup 1][ital P][sub 1])[center dot]Xe([sup 1][Pi][sub 1])[l arrow]Mg(3[ital s]3[ital s] [sup 1][ital S][sub 0])[center dot]Xe ([ital X] [sup 1][Sigma][sup +]) system have been analyzed, yielding absolute vibrational assignments and values of [omega][sub [ital e]x[ital e]]=1.585[plus minus]0.02 and [omega][sub [ital e]]=97.5[plus minus]1.0 cm[sup [minus]1] for the [sup 1][Pi][sub 1] state of [sup 24]Mg[sup 132]Xe. From a Birge--Sponer extrapolation, the well depth of this state is estimated to be 1500 cm[sup [minus]1]. Simulations of rotationally structured spectra of three of the most intense vibrational bands are consistent with [ital R][sup [double prime]][sub [ital e]]=4.56[plus minus]0.12 A for the [ital X] [sup 1][Sigma][sup +] state. From Morse function extrapolation of the excited state rotational constants from the simulations, and Franck--Condon intensity simulations of the [sup 1][Pi][sub 1][l arrow][ital X] [sup 1][Sigma][sup +] vibrational progressions, [ital R][sup [prime]][sub [ital e]] for the [sup 1][Pi][sub 1] state is estimated to be 3.07[plus minus]0.10 A. The [sup 1][Pi][sub 1] state of MgXe fluoresces strongly. The corresponding [sup 1][Pi][sub 1] states of ZnXe and CdXe do not fluoresce, but action'' spectra from the production (via predissociation) of metal atom [sup 3][ital P][sub [ital J]] states are observed. Possible reasons for these differences are discussed in terms of spin--orbit induced predissociation. It is concluded that predissociation of the MgXe([sup 1][Pi][sub 1]) state is not observed because the crossing between the repulsive [sup 3][summation][sup +][sub 1] and the attractive [sup 1][Pi][sub 1] potential curves does not occur until energies higher than those accessible experimentally.

• OSTI ID: 5574169
• Journal Information: Journal of Chemical Physics; (United States), Journal Name: Journal of Chemical Physics; (United States) Vol. 99:12; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

664200* -- Spectra of Atoms & Molecules & their Interactions with Photons-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
ALKALINE EARTH METAL COMPOUNDS
DISSOCIATION
ENERGY LEVELS
EXCITED STATES
EXTRAPOLATION
FLUORESCENCE
FRANCK-CONDON PRINCIPLE
GROUND STATES
LASER SPECTROSCOPY
LUMINESCENCE
MAGNESIUM COMPOUNDS
MORSE POTENTIAL
NUMERICAL SOLUTION
POTENTIALS
PREDISSOCIATION
RARE GAS COMPOUNDS
ROTATIONAL STATES
SIMULATION
SPECTROSCOPY
VAN DER WAALS FORCES
VIBRATIONAL STATES
XENON COMPOUNDS