Application des outils de la chimie quantique et apport de la spectroscopie de Résonance Paramagnétique Électronique pour la caractérisation structurale et dynamique d’Architectures Moléculaires

摘要

The work that will be presented during this defense is dedicated to the application of quantum chemical tools based on Density Functional Theory (DFT) combined with the use of Electron Paramagnetic Resonance (EPR) spectroscopy for the structural and dynamic characterization of molecular compounds related to bioinorganic chemistry. Those research activities deal with the experimental and theoretical study of open-shell systems (organic and inorganic compounds) for applications in biology, environment and catalysis. The main goal of my work is to determine the structural and the dynamic features of the entities in order to find out the optimal conditions to set up the best model systems for reactivity and catalysis purposes. With this work we aim to establish specific relationships connecting the structures, the properties and the reactivities of the species, that will ultimately serve as a basis for predicting geometries, probing structures (in enzymes) and developing new systems (in catalysis or biochemistry). Our approach consist in coupling theoretical methods with experimental ones like those involving continuous-wave and pulse EPR techniques to study the systems from a macroscopic point of view. This approach has been successful to identify unknown species, rationalize their molecular properties and determining magneto-structural correlations. The oral presentation will summarize most of the research work that I have been conducting since I joined the Laboratory of Spectrochemistry Infrared and Raman in 2010. The first part of my presentation will give an overview of the methodological developments that have been done for modeling and predicting the magnetic and spectroscopic properties of hetero-oligomeric transition- metal clusters. In the second part, I will present the different studies I performed on bioinorganic compounds. I will show the relevance of the coupling approach combining experimental and theoretical investigations to characterize such systems. In the last part, I will discuss the perspectives and projects that are directly related to this work and that will use both our methodological developments and our combined approach.