Ultrafast photo-excited dynamics in transition-metal complexes

Understanding, and subsequently being able to manipulate, the excited-state dynamics and decay pathways of photo-excited functional transition-metal complexes is of utmost importance in order to solve grand challenges in solar energy conversion (photocatalysis and solar cells) and data storage. These processes are very complicated and, currently, no single method can encompass all the involved phenomena in coupled electronic and nuclear dynamics in the photo-excited functional molecule as well as the interplay with the surroundings (e.g. a solvent). Using a variety of computational approaches and experimental results, we show how relatively minor variations in the molecular structure of Fe-N-heterocyclic carbene (NHC) complexes lead to completely different excited-state relaxation of the initially excited singlet metal-to-ligand charge-transfer state, and we shed light on both the intra-molecular and molecule-to-solvent energy conversion process subsequent to photo-excitation of bi-metallic complexes.