The millimeter- and submillimeter-wave spectrum of cyanoformamide

Authors:

• Manfred Winnewisser,
• Ivan R. Medvedev,
• Frank C. De Lucia,
• Eric Herbst,
• Jacek Koput,
• K.V.L.N. Sastry,
• Rebecca A. H. Butler

Abstract

The organic species cyanoformamide (NCCONH ₂) is the cyano (CN) derivative of formamide (NH ₂CHO), a known interstellar molecule with a role in the synthesis of nucleic acid precursors under prebiotic conditions. Until quite recently, the rotational spectrum of cyanoformamide had not been studied. Based partially on the results of a newly published microwave study and on the results of our ab initio calculations, we have measured and assigned 2691 transitions of the millimeter- and submillimeter-wave spectrum of this molecule through 360 GHz with the fast-scan submillimeter spectroscopic technique (FASSST). These transitions have been added to the previously measured 135 microwave transitions to produce a global data set of 2826 transitions that was analyzed to within experimental accuracy with a standard asymmetric-top fitting procedure. With the determined spectroscopic constants and dipole moment components, we are able to predict the frequencies and intensities of many additional lines through 400 GHz. Cyanoformamide can now be searched for over a wide frequency range in likely interstellar sources such as hot molecular cores. © 2005. The American Astronomical Society. All rights reserved. Printed in U.S.A.