Chimie Physique Moléculaire Expérimentale
(Experimental Molecular Chemical Physics)
Main theme: High-resolution experimental molecular spectroscopy applied to chemical reactivity and the chemistry of the atmosphere.
Vibration-rotation modeling : astrophysical and dynamical applications
The vibration-rotation structure of polyatomic species is investigated up to highly excited ranges, with special emphasis on acetylene. Polyad or vibrational clusters are built including rotational structure, to reproduce all known literature data within typical high resolution instrumental accuracy. Partition functions are being calculated accounting for nuclear spin statistics. Intramolecular vibrational redistribution is theoretically modeled. Home-made experimental developments are stimulated.
Absorption line profiles and cross sections
Measurements of absorption line parameters (positions, absolute intensities,
widths) and cross sections using Fourier transform spectroscopy,
with state-of-the-art accuracy.
Specific measurements are performed on reactive compounds and/or species in
chemical equilibrium with others, in spectral regions matching the infrared
Molecular agregates and prebiotic molecules
Supersonic jet-cooled molecules are probed at high resolution in the IR and NIR spectral ranges using a variety of instrumental techniques, including near infrared CW-CRDS and Femto-FT-CEAS, with emphasis on small and larger molecular aggregates, and on larger species. Nuclear spin isomerisation processes also motivate some of the experiments.
Reference spectroscopic data
Absorption line parameters (positions, absolute intensities and widths) and cross
sections of molecules measured in the laboratory in the mid-infrared, near-infrared,
visible and ultraviolet ranges (600 – 40000
cm-1) are compiled and provided to the scientific
In addition to a variety of instrumental developments around conventional FTIR spectroscopic techniques, there is a specific effort towards the coupling of optical probes to investigate jet-cooled molecules and aggregates. Femto-FT-CEAS is under development, in particular, merging FTIR, femto comb and high finesse cavity in a single experiment.
We write software to (i) treat high resolution spectra allowing to measure
line profiles parameters including instrumental contribution of lasers or interferometers,
and (ii) analyze spectral structures, such as those
of asymmetric rotors and linear molecules.
Spectral analysis and model-Hamiltonians
High resolution spectra of di- and poly-atomic molecules recorded in various
spectral ranges are analysed. In this framework, we contribute to the theoretical
development of model-Hamiltonians (rotation-vibration-torsion) and computer
codes allowing their resolution.