Rotationally resolved IR spectroscopy of hexamethylenetetramine (HMT) C₆N₄H₁₂

¹ Institut des Sciences Moléculaires d’Orsay, UMR 8214 CNRS-Université Paris-Sud, 91405 Orsay Cedex France
² AILES beamline, Synchrotron SOLEIL Saint aubin, 91140 Gif-sur-Yvette, France
e-mail: olivier.pirali@synchrotron-soleil.fr
³ Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Université de Bourgogne, 9 Av. A. Savary, BP 47870, 21078 Dijon Cedex, France
e-mail: Vincent.Boudon@u-bourgogne.fr
⁴ Université Versailles St-Quentin, UPMC Univ. Paris 06, CNRS, LATMOS, 11 blvd d’Alembert, 78280 Guyancourt, France
e-mail: Nathalie.Carrasco@latmos.ipsl.fr
⁵ Institut Universitaire de France, France
⁶ CNRS-INSU, Institut d’Astrophysique Spatiale, UMR 8617, 91405 Orsay, France
e-mail: emmanuel.dartois@u-psud.fr
⁷ Université Paris Sud, Institut d’Astrophysique Spatiale, UMR 8617, bâtiment 121, 91405 Orsay, France

Received: 13 September 2013
Accepted: 19 November 2013

Abstract

Context. Hexamethylenetetramine (HMT) appears to be a potential constituent of several objects in space, including comets or Titan’s atmosphere and, as an organic residue of ice irradiation in the laboratory, it may be present in the interstellar medium.

Aims. We performed a laboratory study of rotationally resolved intense IR bands of HMT to provide accurate line positions and synthetic spectra to be used for potential astronomical detections.

Methods. We used synchrotron-based high-resolution Fourier transform infrared spectroscopy to record the experimental data. A formalism and programs dedicated to the assignment, analysis, and simulation of absorption spectra of tetrahedral molecules were used to exploit the spectra.

Results. Infrared spectra of gas phase HMT were recorded and accurate wavenumbers and molecular parameters for four intense bands located in the 1000–1500 cm^-1 spectral range suitable for astronomical searches were derived.