Title: Spectroscopy of internal rotors and applications to astrophysical, atmospheric and biological molecules

Venue: 806, T5 building, VNU University of Science, 334 Nguyen Trai, Thanh Xuan, Hanoi

Time: 2h pm, Monday, 26th March 2018

Speaker: Dr. Isabelle Kleiner

Affiliation: Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), CNRS et Universités Paris Est-UPEC et Paris Diderot,  France

 

Abstract: Spectroscopy and optical measurements are amongst the most powerful tools used by geophysicists and astrophysicists to obtain, at distance, information about the planetary atmospheres and about the interstellar medium. Morever spectroscopy also allows us to determine molecular structures and to understand the intra-molecular interactions. The topic of our work concerned mainly molecules containing large amplitude motions and in particular molecules containing one or two methyl (CH3) internal rotors or inversion like in ammonia NH3.

One of the goals of our work is to model the line positions and intensities and to analyse the spectra for these 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 of methyl formate HCOOCH3, methanol CH3OH, acetic acid CH3COOH, acetaldehyde CH3CHO, acetamide CH3CONH2 or methyl acetate molecule CH3-O-C(=O)-CH3, which has been very recently detected in the interstellar cloud Orion thanks our prediction.

Another goal of our work 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 has recently led to the precise determination of molecular structures for the lowest energy conformers of a number of molecules. In this talk, I will show results from molecules which can be considered as prototypes of odorant molecules, like isoamyl acetate (so-called “banana oil”) or linalool, an acyclic mono-terpene present in lavender and other plants and emitted in the earth atmosphere.

 

Biography: Dr Kleiner is Directeur de Recherches at the Centre National de la Recherche Scientifique (CNRS) and belongs to the Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), Université Paris Est-UPEC and Université 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.