Towards iron complexes with new photophysical properties and functions – PhotIron

The interest in organometallic complexes for optical applications such as luminescent materials, photosensitizers,
photocatalysts, biomaterials or nanomaterials for optoelectronics 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. Therefore, the excited state properties in terms of energetics and lifetimes
determine the functional performances of the molecules, and to some extent of nanostructures or devices made of these
molecular building blocks.PhotIron is devoted to the design of light-responsive compounds from cheap and
environmentally benign metal-complexes. While ruthenium complexes have been widely investigated due to ideal
photophysical properties, the price and rarity of Ru limit the industrial development. Our project aims at replacing such
metal by iron that is strategic in the search for low cost device an resource-preservation However, the replacement of
ruthenium by iron is extremely challenging due to a an ultrafast deactivation of the 1,3MLCT states into the low-energy
metal-centered quintuplet 5T2 making Fe-pyridine unexploitable for photonic applications. Based on an interdisciplinary
approach combining synthetic chemistry, quantum chemistry simulations and ultrafast spectroscopy, the aim of the current
project is to understand and rationalize the impact of the chemical structure of iron complexes on their photophysical
properties in order to operate a proper design for photochemical applications.