dc.creator Pearson, John C. en_US dc.creator Brauer, Carolyn S. en_US dc.creator Yu, Shanshan en_US dc.creator Drouin, Brian J. en_US dc.date.accessioned 2009-07-29T13:02:57Z dc.date.available 2009-07-29T13:02:57Z dc.date.issued 2009 en_US dc.identifier 2009-WH-13 en_US dc.identifier.uri http://hdl.handle.net/1811/38339 dc.description Author Institution: JET PROPULSION LABORATORY, CALIFORNIA INSTITUTE OF TECHNOLOGY, 4800 OAK GROVE DR., PASADENA, CA 91109 en_US dc.description.abstract Propionitrile is a well known interstellar molecule that is a closely associated with warm dust near ultra compact $H_{II}$ regions. In these regions the C$_2$H$_5$CN column can reach $10^{17}$ and the rotational temperature often equals the vibrational temperature and exceeds 200 K, populating all the low-lying vibrational states. The rotational spectrum of the third lowest excited vibrational state, the 378 cm$^{-1}$ out-of-plane bending state, $\nu_{20}$, of propionitrile, which was previously identified at millimeter wavelengths in both the laboratory and the interstellar medium, has been characterized to high angular momentum quantum numbers. This state is surprisingly isolated considering its proximity to the overtone of the in-plane bend, 2$\nu_{13}$, the excited torsional state of the in-plane bend, $\nu_{13}+\nu_{21}$, and the second excited torsional state, $2\nu_{21}$, which lie approximately 35 cm$^{-1}$ higher. The only surprising aspect is the presence of significantly larger torsional A-E splitting than observed in either the ground state or the $\nu_{13}$ in the absence of a resonance with $\nu_{21}$. Because $\nu_{20}$ has been observed in high mass star forming cores in the millimeter, its higher angular momentum lines are known to be a major source of line confusion in high mass star forming cores. The spectrum, constants and determined barriers will be presented. en_US dc.language.iso English en_US dc.publisher Ohio State University en_US dc.title SUBMILLIMETER SPECTROSCOPY OF THE OUT-OF-PLANE BENDING STATE $\nu_{20}$ OF C$_2$H$_5$CN en_US dc.type Article en_US
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