" Soutenance de l’Habilitation à Diriger des Recherches de Svetlana V. ELISEEVA. | Université d'Orléans

Université d'Orléans

Soutenance de l’Habilitation à Diriger des Recherches de Svetlana V. ELISEEVA.

30/01/2018 - 14:00 - 30/01/2018 - 18:00

URL: http://www.univ-orleans.fr/actus/soutenances

Nom du contact: Etudes Doctorales

Courriel du contact: etudes.doctorales@univ-orleans.fr

Lieu: Auditorium Charles Sadron - 3E avenue de la Recherche Scientifique - campus CNRS Orléans

Discipline : Chimie

Résumé :

Trivalent lanthanide(III) ions, Ln3+, due to their specific electronic configuration ([Xe]4fn, n = 0–14) and the shielding of the 4f orbitals by the outer 5s25p6 subshells exhibit unique optical properties, in particular (i) sharp characteristic bands arising from f-f transitions, in the entire spectrum from UV, to near-infrared (NIR), the wavelengths of which are insignificantly affected by changes in the local microenvironment around Ln3+ (pH, temperature, hydrophilic and hydrophobic character of biological molecules) and (ii) long luminescence lifetimes compared to organic fluorophores (ns-µs or µs-ms range for NIR- or visible-emitting Ln3+, respectively). However, extremely low molar absorption coefficients of free Ln3+ require their sensitization by the “antenna effect” via appropriate chromophoric ligands in order to obtain sufficient emission intensity. Therefore, the design of highly luminescent Ln3+ compounds requires an optimization of the sensitization processes as well as the minimization of non-radiative deactivation mechanisms through overtones of high-energy vibrations, charge-transfer states, as well as back energy transfer processes. Moreover, if Ln3+ coordination compounds are thought to be used in a specific application, additional requirements such as thermal stability and easy processing for light-emitting diodes or water solubility, biocompatibility, low toxicity, high thermodynamic stability and/or kinetic inertness for biological applications, have to be taken into account. The research carrier of Dr. Svetlana V. ELISEEVA is mainly dealing with the design, synthesis, characterization and use of lanthanide(III) coordination compounds emitting in the visible and the NIR ranges for material sciences and biological applications. Detailed investigation of photophysical properties and rationalization of the design of highly luminescent Ln3+ complexes bearing in mind other functional properties required for a specific application are important aspects of her research activity and projects. Ln3+-based compounds from different classes including small molecular complexes, macromolecules (dendrimers), coordination polymers and nanomaterials have been created to reach these goals.