Missions

The general objective of this PhD project is to develop new functionalization reactions based on plasma activation of organic solvents. The project will focus in particular on the methylation and subsequently the cyanation of non-volatile molecules, both of which are key transformations in organic chemistry. To achieve this goal, several sub-objectives have been defined:

(i) The first phase of the project will focus on screening various organic solvents capable of generating radicals suitable for methylation and cyanation of dissolved substrates. The main goal of this stage is to identify the most appropriate solvent by:

Screening candidate solvents,

Developing methods to quantify radicals in the liquid phase,

Conducting a parametric study to optimize the diffusion of target radicals into the liquid phase,

Gaining mechanistic insight into solvent fragmentation and recombination through kinetic modeling.

(ii) The second phase will address the functionalization of dissolved substrates. A broad range of molecular substrates will be explored, from classical organic molecules to highly complex compounds. The key objective is to study radical reaction mechanisms to address challenges of chemoselectivity, regioselectivity, and stereoselectivity in the developed transformations. The ultimate goal is to discover novel synthetic pathways and identify reactions with high potential for applications in fine chemical synthesis, focusing primarily on methylation and cyanation reactions.

Activités

The aim will be to carry out continuous-flow chemical reactions under plasma activation, and to assess the process performance using standard analytical techniques commonly employed in organic chemistry (GC, GC/MS, NMR).

Compétences

Regular meetings with the team are planned, along with progress reports every six months and at least one publication expected during the PhD.

Résultats attendus et contrôles

Il est prévu des points réguliers aupres de l'équipe, des rapports tous les 6 mois, et a minima une publication au cours de la thèse

Contexte de travail

The "Processes, Plasmas, Microsystems" (2PM) team at the Institut de Recherche de Chimie Paris (IRCP) investigates the integration of non-thermal plasma into continuous-flow chemical processes as an alternative activation method. This approach holds strong potential for the development of novel synthetic routes and the design of more sustainable processes. It involves generating a plasma in the gas phase in direct contact with a liquid solution, allowing for intense interactions between short-lived reactive plasma species and species from the liquid phase. Optimizing plasma–liquid interactions has led to the design of various gas–liquid biphasic microreactors operating in flow.

Several new synthetic pathways have been explored using plasma activation, in collaboration with the Institut Parisien de Chimie Moléculaire (IPCM) at Sorbonne Université. This technology has been used in particular to functionalize volatile molecules using plasmas generated from different gases, such as O₂ for oxidation and NH₃ for amination [4–6]. However, this strategy is inherently limited to the incorporation of low-molecular-weight functional groups — such as =O or –NH₂ — that can be derived from the gas phase.

The original concept of this project is to use the solvent itself as the source of functionalization, rather than relying on the gas. In this novel strategy, the solvent is first activated by the plasma, then reacts with the substrate. For example, this approach has already been investigated using water as the solvent to generate OH radicals. It enables the formation of high concentrations of reactive species in both gas and liquid phases using only small amounts of Ar or He plasma. This opens the possibility of generating a broad range of reactive intermediates from various liquids.

The investigation of solvent activation by plasma will be carried out in microstructured reactors integrated into automated sequential-flow processes. This PhD is part of the ANR PlasmaSolve project, which brings together complementary expertise in radical chemistry from Prof. Louis Fensterbank (Collège de France) and Dr. Cyril Ollivier (IPCM / Sorbonne Université). The PhD student will be closely supported by a postdoctoral researcher working on the development of new gas–liquid reactor geometries.

Contraintes et risques

Low chemical risk due to confinement in miniaturized systems.
Very low electrical risk from the plasma source, provided appropriate training is completed

Informations complémentaires

Main experiments will take place at IPGG for microfluidic development