HIGH RESOLUTION IR SPECTROSCOPY AND ANALYSIS OF THE BENDING DYAD OF RuO4

RuO$_{4}$ is a heavy tetrahedral molecule of interest in several fields. Due to its chemical toxicity and radiological impact of its 103 and 106 isotopologues, the possible remote sensing of this compound in the atmosphere in case of possible severe nuclear accident has renewed interest in its spectroscopic properties. We investigate here, for the first time at high resolution, the bending modes region in the far infrared. High resolution FTIR spectra have been recorded near room temperature, using a specially constructed cell and an isotopically pure sample of $^{102}$RuO$_{4}$. New assignments and effective Hamiltonian parameter fits for the main isotopologue ($^{102}$RuO$_{4}$) have been performed, treating the whole \nub{2}-\nub{4} bending mode dyad. We provide precise effective Hamiltonian parameters, including band centers and Coriolis interaction parameters [1]. [1] S. Reymond-Laruinaz, M. Faye, V. Boudon, D. Doizi, L. Manceron, “High-resolution Infrared Spectroscopy and analysis of the \nub{2}-\nub{4} bending dyad of Ruthenium Tetroxide”, J. Mol. Spectrosc. 336 (2017) 29

NEW DATA AND ANALYSIS FOR SF6 ABSORPTION MODELLING IN THE 10 MICRON ATMOSPHERIC WINDOW

Modelling correctly the SF$_{6}$ atmospheric absorption requires the knowledge of the spectroscopic parameters of all states involved in the many hot bands in the 10 $\mu$m atmospheric window used for remote sensing. Since a direct analysis of the hot bands near the \nub{3} absorption of SF$_{6}$ in this atmospheric window is not possible, due to their overlapping, we use another strategy, gathering information in the far and mid infrared regions on initial and final states to compute the relevant total absorption. In this talk, we present new results of an analysis of spectra recorded at the AILES beam line at the SOLEIL Synchrotron facility. For these measurements, we used an IFS125HR interferometer in the 100 to 3200 \wn range, coupled to a cryogenic multiple pass cell. The optical path length was varied from 45 to 141 m with 223 and 153 K temperatures. New information has been obtained on the \nub{3} + \nub{5} band which, combined with improved parameters for \nub{5}, is used to model the important \nub{3}+\nub{5} - \nub{5} hot band contribution [1]. Also, data have been obtained on the \nub{3} band of the $^{36}$SF$_{6}$ isotopic species present in very low abundance (0.0002) [2]. These new parameters will be included in the XTDS model [3] and VAMDC/SheCaSDa database [4], thus improving the previous SF$_{6}$ parameters. [1] M. Faye, L. Manceron, P. Roy, V. Boudon, M. Loete, “First analysis of the \nub{3}+\nub{5} combination band of SF$_{6}$ observed at Doppler-limited resolution and effective model for the \nub{3}+\nub{5}-\nub{5} hot band” J. Mol. Spectrosc., in press. [2] M. Faye, L. Manceron, P. Roy, V. Boudon, M. Loete, “First high resolution analysis of the \nub{3} band of the $^{36}$SF$_{6}$ isotopologue”, J. Mol. Spectrosc., in press. [3] C. Wenger, V. Boudon, M. Rotger, M. Sanzharov, and J.-P. Champion,”XTDS and SPVIEW: Graphical tools for Analysis and Simlation of High Resolution Molecular Spectra”, J. Mol. Spectrosc. 251, 102 (2008). [4] http://vamdc.icb.cnrs.fr/PHP/shecasda.ph

HIGH RESOLUTION IR SPECTROSCOPY AND ANALYSIS OF THE BENDING DYAD OF RuO4

RuO$_{4}$ is a heavy tetrahedral molecule of interest in several fields. Due to its chemical toxicity and radiological impact of its 103 and 106 isotopologues, the possible remote sensing of this compound in the atmosphere in case of possible severe nuclear accident has renewed interest in its spectroscopic properties. We investigate here, for the first time at high resolution, the bending modes region in the far infrared. High resolution FTIR spectra have been recorded near room temperature, using a specially constructed cell and an isotopically pure sample of $^{102}$RuO$_{4}$. New assignments and effective Hamiltonian parameter fits for the main isotopologue ($^{102}$RuO$_{4}$) have been performed, treating the whole \nub{2}-\nub{4} bending mode dyad. We provide precise effective Hamiltonian parameters, including band centers and Coriolis interaction parameters [1]. [1] S. Reymond-Laruinaz, M. Faye, V. Boudon, D. Doizi, L. Manceron, “High-resolution Infrared Spectroscopy and analysis of the \nub{2}-\nub{4} bending dyad of Ruthenium Tetroxide”, J. Mol. Spectrosc. 336 (2017) 29

NEW DATA AND ANALYSIS FOR SF6 ABSORPTION MODELLING IN THE 10 MICRON ATMOSPHERIC WINDOW

Modelling correctly the SF$_{6}$ atmospheric absorption requires the knowledge of the spectroscopic parameters of all states involved in the many hot bands in the 10 $\mu$m atmospheric window used for remote sensing. Since a direct analysis of the hot bands near the \nub{3} absorption of SF$_{6}$ in this atmospheric window is not possible, due to their overlapping, we use another strategy, gathering information in the far and mid infrared regions on initial and final states to compute the relevant total absorption. In this talk, we present new results of an analysis of spectra recorded at the AILES beam line at the SOLEIL Synchrotron facility. For these measurements, we used an IFS125HR interferometer in the 100 to 3200 \wn range, coupled to a cryogenic multiple pass cell. The optical path length was varied from 45 to 141 m with 223 and 153 K temperatures. New information has been obtained on the \nub{3} + \nub{5} band which, combined with improved parameters for \nub{5}, is used to model the important \nub{3}+\nub{5} - \nub{5} hot band contribution [1]. Also, data have been obtained on the \nub{3} band of the $^{36}$SF$_{6}$ isotopic species present in very low abundance (0.0002) [2]. These new parameters will be included in the XTDS model [3] and VAMDC/SheCaSDa database [4], thus improving the previous SF$_{6}$ parameters. [1] M. Faye, L. Manceron, P. Roy, V. Boudon, M. Loete, “First analysis of the \nub{3}+\nub{5} combination band of SF$_{6}$ observed at Doppler-limited resolution and effective model for the \nub{3}+\nub{5}-\nub{5} hot band” J. Mol. Spectrosc., in press. [2] M. Faye, L. Manceron, P. Roy, V. Boudon, M. Loete, “First high resolution analysis of the \nub{3} band of the $^{36}$SF$_{6}$ isotopologue”, J. Mol. Spectrosc., in press. [3] C. Wenger, V. Boudon, M. Rotger, M. Sanzharov, and J.-P. Champion,”XTDS and SPVIEW: Graphical tools for Analysis and Simlation of High Resolution Molecular Spectra”, J. Mol. Spectrosc. 251, 102 (2008). [4] http://vamdc.icb.cnrs.fr/PHP/shecasda.ph

Etude des premières étapes réactionnelles de l'oxydation du cobalt mono- et diatomique par l'oxygène moléculaire par isolation en matrice de gaz rare et spectroscopies d'absorption électronique et vibrationnelle

PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF

The copper carbonyl complexes revisited: Why are the infrared spectra and structures of copper mono and dicarbonyl so different?

International audienceNew Infrared absorption data have been obtained using isolation in solid argon and neon on copper carbonyl molecules, CuCO and Cu(CO) 2 , two very reactive molecules. For CuCO, all three fundamentals are now observed and it presents an unusually large matrix effect, in line with former results indicating a weak metal carbon interaction and a large total dipole moment. With help of isotopic effects, new data indicates unambiguously that Cu(CO) 2 is linear and presents a notably stronger metal-carbon interaction than CuCO. Quantum chemical calculation have been carried out at the CCSD(T) level for determining energies and structural properties, as well as spectroscopic observables. The results enable an assessment of the high stability of the Cu(CO) 2 molecule (first bond dissociation energy of 66 kJ/mole) which suggest that observation at room temperature is possible and give a first evidence of Renner effect on a penta-atomic molecule

Optimisation de la source synchrotron cohérente dans le domaine des Térahertz pour la spectroscopie à haute résolution de molécules d'intérêt astrophysique

La spectroscopie par transformée de Fourier est l outil multiplexe de mesure de spectres à haute résolution le plus utilisé dans l infrarouge. Son extension au domaine Térahertz se révèle de grand intérêt pour la spectroscopie de molécules présentes dans le milieu interstellaire, mais se heurte à différents obstacles : en particulier, aucune source large bande n'est suffisamment intense et stable pour ces applications. Cette thèse présente des développements instrumentaux basés sur l exploitation du rayonnement synchrotron cohérent (CSR) sur la ligne AILES du synchrotron SOLEIL, optimisée pour l'infrarouge lointain. Les conditions de production du CSR sont étudiées pour les besoins des analyses spectroscopiques à haute résolution ; les performances de cette source sont caractérisées et comparées à celles du rayonnement incohérent. La mise en place d'un système de double détection permet une correction de l'effet des instabilités de la source et une augmentation conséquente du rapport signal-sur-bruit. Ces développements sont appliqués à la mesure de spectres de rotation pure ; une modélisation améliorée du spectre dans l'état fondamental de la molécule de propynal a ainsi pu être faite, prouvant la complémentarité de la source étudiée vis-à-vis des sources micro-onde ou infrarouge classiques.Fourier Transform spectroscopy is the most used multiplex tool for high-resolution measurements in the infrared range. Its extension to the Terahertz domain is of great interest for spectroscopic studies of interstellar molecules. This application is however hampered by the lack of dedicated, broadband sources with a sufficient intensity and stability. In this work, Coherent Synchrotron Radiation (CSR) was used as a source for molecular spectroscopy at high resolution on the AILES infrared and Terahertz beamline of SOLEIL synchrotron. The beamline being optimized for far-infrared, we could characterize the properties of CSR and compare them to the incoherent synchrotron radiation. A double detection system allowed to correct the effect of the source-related instabilities, hence to significantly increase the signal-to-noise ratio. Pure rotational spectra were measured using these developments. The case of the propynal molecule, for which a refined set of rotational and centrifugal distortion constants was calculated, proves the complementarity between CSR and the classical microwave or infrared sources.PARIS11-SCD-Bib. électronique (914719901) / SudocSudocFranceF