Thèse soutenue

Spectroscopie infrarouge, cinétique et caractérisation de molécules aromatiques : implications astrophysiques
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Accès à la thèse
Auteur / Autrice : Vijayanand Chandrasekaran
Direction : Robert GeorgesLudovic Biennier
Type : Thèse de doctorat
Discipline(s) : Physique
Date : Soutenance en 2010
Etablissement(s) : Rennes 1
Ecole(s) doctorale(s) : École doctorale Sciences de la matière (Rennes ; 1996-2016)
Partenaire(s) de recherche : autre partenaire : Université européenne de Bretagne (2007-2016)

Mots clés

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Résumé

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This thesis is devoted to the investigation of the spectroscopy, kinetics and characterization of aromatic molecules. The manuscript is organized accordingly in three parts. In the first part, we report the first direct absorption infrared spectroscopy of the benzene dimer in the 3. 3 micron region corresponding to the C-H fundamental stretch of the benzene monomer. The presence of new bands in the spectrum and the red shift of the C-H fundamental stretch are analyzed in detail. We extend this work to benzene clusters and benzene-argon complexes. For benzene clusters, the results are discussed in terms of solid phase of the clusters. For benzene-argon complexes, we measured high resolution spectra in the 3. 3 micron region which are under analysis. In the second section of the thesis, the kinetics of anthracene dimerization at 60 K, 80 K, 120 K, 235 K and 470 K using the CRESU (Kinetics of Reactions in Supersonic Uniform Flows) technique has been studied. The rate constant of dimerization at 60 K has been obtained. Our findings are employed to assess the role of PAH nucleation in haze formation in Jupiter’s polar atmosphere. Finally the carbonaceous material formed by pyrolysis of acetylene in a unique high temperature reactor has been explored. A variety of techniques such as H-NMR, IR and XRD have been used to unravel the intimate chemical and physical structures of the material.