Orateur
Description
Vibrational circular dichroism (VCD) is the tiny difference in absorption between right- and left-circular polarised light in the infrared range for a chiral molecule. Besides its use for determining absolute configurations of chiral molecules,(1) it is a very subtle probe of molecular conformations, aggregation, and interactions with the solvent.(2-3)
Although VCD has been mostly applied so far to species in solution, recent theoretical advances now allow obtaining reliable spectra also in the solid phase.(4-5) There, the sensitivity of VCD to structural factors makes it a good probe of the crystal structure, in particular polymorphism that plays a major role in pharmaceutical sciences. We present here recent results on the interpretation of VCD spectra crystal of alcohols or diols in the solid state. We show that the crystal symmetry influences the non-local contributions to the VCD spectrum, which strongly modify its shape. Finally, we will show how VCD spectra can be taken as a signature of the formation of co-crystals between a chiral anti inflammatory drug, Naproxen, and an amino-acid.
- Merten, C. Recent Advances in the Application of Vibrational Circular Dichroism Spectroscopy for the Characterization of Asymmetric Catalysts. European Journal of Organic Chemistry 2020, 2020 (37), 5892-5900.
- Le Barbu-Debus, K.; Bowles, J.; Jähnigen, S.; Clavaguéra, C.; Calvo, F.; Vuilleumier, R.; Zehnacker, A. Assessing cluster models of solvation for the description of vibrational circular dichroism spectra: synergy between static and dynamic approaches. Physical Chemistry Chemical Physics 2020, 22 (45), 26047-26068.
- Buffeteau, T.; Cavagnat, D.; Bouchet, A.; Brotin, T. Vibrational absorption and circular dichroism studies of (-)-camphanic acid. Journal of Physical Chemistry A 2007, 111 (6), 1045-1051.
- Jähnigen, S.; Scherrer, A.; Vuilleumier, R.; Sebastiani, D. Chiral Crystal Packing Induces Enhancement of Vibrational Circular Dichroism. Angewandte Chemie-International Edition 2018, 57 (40), 13344-13348.
- Jahnigen, S.; Zehnacker, A.; Vuilleumier, R. Computation of Solid-State Vibrational Circular Dichroism in the Periodic Gauge. Journal of Physical Chemistry Letters 2021, 12 (30), 7213-7220.
| Affiliation de l'auteur principal | ISMO (Institut des Sciences Moléculaires d'Orsay) CNRS |
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