Defining the electronic structure of polyradical architectures, as well as complexes involving both redox-active ligands and redox-active metals under various oxidation states is a challenging task, which requires solid state data, electrochemical, spectroscopic and theoretical tools. This is only a combination of all of these techniques that allows for an unambiguous assignment.  The redox properties are investigated by cyclic/differential pulse/rotating disk electrode voltammetries and electrolysis. The X-Ray diffraction data provides a structural basis for investigating the compounds by optical spectroscopy. In particular, NIR spectroscopy proved to be very useful due to a small HOMO-LUMO gap in most of our radical compounds. It allows for assigning the redox processes i.e. ligand- vs. metal-centered oxidations. It also gives access to the delocalization and electronic communication within the radical complexes. 

We routinely combine optical spectroscopies to EPR spectroscopy for probing the spin state of the radical compounds, the nature of the SOMO and the magnetic interaction in multispin systems. We are equipped with dual-mode resonator (perpendicular/parallel modes), and cryostats to cover the temperature range 4-298 K at the X-Band frequency. We also measure at the Q-Band frequency with a helium flow cryostat. These experimental data are rationalized by theoretical calculations based on the density functional theory (DFT). 

Mis à jour le 28 juin 2018