Institut des Sciences Moléculaires d'Orsay



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MOlecules in MAtrices

By studying molecules in inert and low-temperature matrices, we seek to understand, evaluate and exploit the role of the environment on fundamental processes such as electronic and vibrational relaxation as well as processess of interest for chemical reactivity.

The systems of interest are trapped in cryogenic solids (matrices). We explore their spectroscopic properties and dynamics at low temperature. The advantages of crystalline solids such as rare gas matrices and solid para-hydrogen (quantum "host") lie in their weak interactions with the system. Matrix isolation studies also bring invaluable tools for the characterisation of metastable species (radicals, intermediates) or molecular phosphorescence measurement which can be tricky to probe in gas-phase experiments. We seek to explore, understand, and monitor the role of the matrix environment on fundamental molecular processes such as electronic/vibrational relaxation, photochemical processes, etc.

Systems of interest: small hydrogen-bonded systems, molecules with large amplitude motions, cyanopolyynes molecules, porphyrines and phthalocyanines, metal-carbonyl complexes.

Tools: spectroscopic techniques from the infrared to the ultraviolet domain. We are concerned with dynamics from the picosecond to longer timescales (weeks).

Contacts : The group is composed of
* - four permanent members : Claudine Crépin-Gilbert (DR CNRS - chef de groupe), Michèle Chevalier (MCF Univ. Paris Sud), Didier Chamma (MCF), Wutharath Chin ->] (CR CNRS)
* - two undergrad. students: Alejandro Gutierrez-Quintanilla, Urszula Szczepaniak (co-tutelle avec IPC-PAS, Institute of Physical Chemistry - Polish Academy of Sciences, Varsovie)
* - Alumni : Rolando Lozada-Garcia (defended in 2013), Raphaël Thon (defended in 2013), Justinas Ceponkus (Univ. Vilnius, Lithuania)

Topics: Spectroscopy, photoreactivity and dynamics

- Photoréactivité : isomerisation and fragmentation studies in inert matrices induced by IR or UV/visible laser excitation.

- Molecules of atmospheric interest: Photoreactivity of cyanopolyynes HCnN

- Tetrapyrrolic systems : Porphyrine et phtalocyanine

- Vibrational dynamics : The vibrational relaxation of organometallic complexes is probed by means of IR nonlinear spectroscopy such as the degenerate four-wave mixing photon echo technique at the pico- and femtosecond timescale. This gives access to the vibrational coherence and to the relaxation of the population.

Our research activities encompass both experimental and theoretical studies.


  • Cryogenic systems: matrix isolations studies of molecular assemblies in inert matrices (N2, Ne, Ar, Xe…)
  • Solid parahydrogen set-up
  • Analysis by means of electronic spectroscopy (absorption, emission) and linear (FTIR) and nonlinear (photon echoes) IR spectroscopy
  • Quantum chemistry (ab initio and DFT - density functional theory): electronic structures and frequency calculations


Molécules et complexes à liaison hydrogène et/ou d’intérêt biologique, espèces moléculaires d’intérêt astrophysique.

  • Petites molécules organiques à liaisons H : glycolaldéhyde, acétylacétone

Cyano-carbonaceous chains

Photochemistry of cyanopolyyne molecules

In-situ irradiation of HC3N molecules in cryogenic matrices with UV laser leads to the formation of longer carbon–nitrogen chains: HC5N, C4N2 ou C6N2. This novel synthesis has also been successfully applied to produce HC7N from the HC5N-C2H2 precursor complexes. Identification of these novel species is performed through IR vibrational spectroscopy, electronic luminescence spectroscopy, isotope labelling, and theoretical calculations. Raman and phosphorescence studies are obtained in (…)

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Molecules in Matrices (MOMA) - English version

Permanent staff : Claudine Crépin-Gilbert (group leader), Didier Chamma, Michèle Chevalier, Wutharath Chin
PhD students : Alejandro Gutierrez Quintanilla (to be coming), Rolando Lozada-Garcia (former), Raphaël Thon (former)
Group picture
Research activities Dynamics and molecular spectroscopy in cryogenic solids
Our research activities focus on the influence of the environment surrounding a molecular system. To better understand, examine and exploit such effect on fundamental molecular (…)

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