High resolution Spectroscopy of small organic molecules and astrophysical molecules-量子物質科學協同創新中心

報告題目： High resolution Spectroscopy of small organic molecules and astrophysical molecules 報告人： Dr. Isabelle Kleiner Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), CNRS et Universités Paris Est-UPEC et Paris Diderot France 報告時間： 10月28日（星期一）上午 10:30 報告地點：理科樓三樓報告廳摘要： The topic of our work concerns mainly molecules containing large amplitude motions and in particular molecules containing one or two methyl (CH3) internal rotors. One of the goals of our work is to describe with our theoretical method and codes (using effective Hamiltonians describing the rotation-torsion-vibration interactions) the energy levels and then the line positions and intensities for this type of molecules. That way we can provide reliable predictions of line positions and intensities for astrophysical molecules containing one internal rotor CH3, such as the isotopic species ofmethyl formate HCOOCH3, methanol CH3OH, acetic acid CH3COOH, acetaldehyde CH3CHO or acetamide CH3CONH2. The major new facilities, the Herschel Space Observatory and the Atacama Large Millimeter Array (ALMA), in Chili, now open the sub-millimeter region up to a few THz for astronomical observations by making investigations with unprecedented high sensitivity and resolution. Molecules which undergo internal rotation of a methyl group present thousands of lines in this spectral range and therefore their spectra are particularly important to model. We will show some of the recent results in the microwave, millimeter or infrared range for those molecules. We will also present recent results for the study of a two-top internal rotor, the methyl acetate molecule CH3-O-C(=O)-CH3, which has been very recently detected in the interstellar cloud Orion thanks our prediction. Another goal is to get some knowledge of the structural properties of small organic molecules or biomimetic molecules. Fourier transform microwave spectroscopy in the gas phase coupled with high level quantum chemical calculations or ab initio calculations has recently led to the precise and detailed determination of molecular structures for the lowest energy conformers of a number of molecules. In this talk, we will show results from molecules which can be considered as prototypes of odorant molecules, like isoamyl acetate or linalool, an acyclic mono-terpene.
Dr Kleiner is Directeur de Recherches at the Centre National de la Recherche Scientifique (CNRS) and belongs to the Laboratoire Interuniversitaire des Syst貓mes Atmosph茅riques (LISA), Universit茅 Paris Est-UPEC and Universit茅 Paris Diderot in France. She did her Ph.D at the University Libre de Bruxelles (Belgium) and her post-doctoral fellowship with Dr Jon. T. Hougen at the National Institute for Standards and Technology (NIST, USA). Her field is high resolution spectroscopy and in particular the modelling of the large amplitude motion and internal rotation of one or more methyl groups with application to astrophysical and biomimetic molecules, but also modelling of infrared spectra for planetological applications for C3v molecules such as ammonia NH3, phosphine PH3, acetonitrile CH3CN, etc.