The Lowest Vibrational States Of Urea From The Rotational Spectrum

Kisiel, Zbigniew

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https://hdl.handle.net/2142/50820 Copy

Description

Title

The Lowest Vibrational States Of Urea From The Rotational Spectrum

Author(s)

Kisiel, Zbigniew

Contributor(s)

• Medvedev, Ivan
• Thomas, Jessica

Issue Date

2014-06-17

Keyword(s)

Astronomy

Abstract

The urea molecule, (NH$_2$)$_2$CO, has a complex potential energy surface resulting from a combination of the NH$_2$ torsion and NH$_2$ inversion motions. This leads to a distribution of lowest vibrational states that is expected to be significantly different from the more familiar picture from simple inversion or normal mode models.\footnote{P.D.Godfrey, R.D.Brown, A.N.Hunter {\it J.~Mol.~Struct.}, {\bf 413-414}, 405-414 (1997).}$^,$\footnote{N.Inostroza, M.L.Senent, {\it Chem.~Phys.~Lett.}, {\bf 524}, 25 (2012).} \vspace{0.5cm} The broadband 207-500 GHz spectrum of urea recorded in Dayton has signal to noise sufficient for assignment of rotational transitions in excited vibrational states up to at least 500 cm$^{-1}$. In addition to the previously reported analysis of the ground and the lowest excited state we have been able to assign transitions in at least five other excited vibrational states. Strongly perturbed transitions in a close doublet of such states have been fitted to within experimental accuracy with a coupled fit and a splitting in the region of 1 cm$^{-1}$. These assignments combined with vibrational energy estimates from relative intensity measurements allow for empirical discrimination between different models for the energy level manifestation of the large amplitude motions in urea.$^b$

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

English

Permalink

http://hdl.handle.net/2142/50820

DOI

https://doi.org/10.15278/isms.2014.TA10

Copyright and License Information

Copyright 2014 by the authors. Licensed under a Creative Commons Attribution 4.0 International License. http://creativecommons.org/licenses/by/4.0/

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