Philippe C. Gros studied chemistry at the University of Lyon and obtained his Ph.D in 1992. He then worked for two years as a postdoctoral fellow on a CNRS-Isochem Company on phosgene derivatives chemistry. In 1994 he entered the CNRS as Research Associate in the Laboratory of Pr. Paul Caubère at the Nancy University. He received his Habilitation in 2000 and has been appointed Research Director in 2006. His current research interests include the design of new metallating agents (organolithiums, ate-complexes) for the regio- enantioselective functionalization of heterocycles, structural and reaction mechanism investigation, transition metal-catalyzed cross-couplings for ligand synthesis, and the building of photo- and electroactive organometallic materials for various applications including solar energy.
The interest in organometallic complexes for optical applications is growing continuously. The development of such applications implies the careful design of metal complexes with appropriate photophysical properties to ensure efficient light harvesting based on strong and broadband molecular absorption or exciton generation in the condensed phase and excited state charge or energy transfer. Ruthenium polypyridine complexes have long been considered as lead compounds due to their ideal photophysical and geometrical properties. And used with success in Dye-sensitized Solar Cells (DSSCs) with efficiencies in the 9-12 % range. Our group has reported several new ruthenium complexes with improved absorption domains thanks to ligand tuning. While ruthenium-based complexes have been widely investigated and used in many different lab scale applications it is a scarce metal. In contrast iron, belonging to the same group of the periodic table, is naturally abundant, of low cost and low toxicity and thus appears as an ideal substitute.
However, the replacement of ruthenium by iron is extremely challenging since in Fe-pyridine complexes an ultrafast non-radiative deactivation of the 1,3MLCT states into the low-energy metal-centered quintuplet 5T2 make Fe-pyridine unexploitable for applications requiring higher free energies.
Our group has reported new carbene-based ligands for the stabilization of the 3MLCT state in iron complexes, clearly demonstrated by means of ultrafast photophysics, together with a concomitant destabilization of the MC state. We have shown that several of our iron complexes can sensitize the TiO2 semiconductor in a laboratory DSSC, leading to measurable photocurrent and power conversion efficiency. We have obtained the longest 3MLCT state ever reported for iron(II) complexes.
The conference will present our works on the preparation of ruthenium and iron complexes with focus on the chemical tuning of electronic and photophysical properties as well as their applications in DSSCs.
Audience Take away:
• How to design a specific metal-complex for solar energy
• How synthetic chemistry can tune the photochemical properties of a complex
• New insights into iron coordination chemistry
• New route towards more eco-friendly light responsive devices