Eigenstate resolved infrared spectroscopy of 1,1,1-d{sub 3}-ethane in the region around 5900 cm{sup -1}

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:437238

Dolce, J W; Callegari, A; Srivastava, H K; Lehman, K K; Scoles, G ^[1]

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1. Princeton Univ., NJ (United States)

This talk will describe results which are part of a series of experiments studying intramolecular vibrational energy redistribution (IVR) in medium size molecules containing a methyl group. Last year the authors reported on methylsilane, while this year they will discuss the results for 1,1,1-d{sub 3}-ethane also obtained using optothermal detection, cavity enhanced, molecular beam laser spectroscopy. A 9 cm{sup -1} wide section in the 5900 cm{sup -1} GH stretch overtone region was observed. All molecules with an axial methyl group have a strong parallel band in this region with band origins within a few cm{sup -1} of each other. It is believed that the best zero order assignment for these bands is as the first overtone of the assymetric methyl CH stretch. For the CH{sub 3}CD{sub 3} band, Lawrence-Knight deconvolution of the rotationally assigned transitions reveals that the coupling strengths of this state to the nearly isoenergetic background of vibrational states range from 1 x 10{sup -3} to 25 x 10{sup -3} cm{sup -1}. The observed coupling strengths do not show a systematic dependence from the rotational quantum number for the low J,K values that were observed in the beam experiment, and therefore appear to be dominated by inharmonic forces. These results will be discussed in light of those previously obtained for methylsilane and other similar molecules.

• OSTI ID: 437238
• Report Number(s): CONF-9606118--
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
ABSORPTION SPECTROSCOPY
DEUTERIUM COMPOUNDS
ETHANE
LASER SPECTROSCOPY
VIBRATIONAL STATES