Molecular snapshot in solar energy conversion processes

A decade of studies on excited state structures of transition metal complexes for solar energy conversion using laser and x-ray transient absorption spectroscopy will be briefly reviewed including the details for the excited state dynamics, structural diversity in solution andhot vibrational states. We will discussthree examples on metalloporphyrins excited state structure and photoinducedligation/deligation, interplays of structure and dynamics of MLCT excitedstate transition metal complexes for photoinduced charge separation andelectron transfer, and excited state transition metal complexes at interfaces of hybrid material for solar electricity generation/catalysis. The current advances and limitations in resolving excited stat structures during photochemical reactions will be presented. New needs in theoretical computation and modeling will be addressed for these studies to exert the full potentials of resolving otherwise elusive excited state structures. The potential and prospective in excited state structural dynamics studies using new light sources, such as XFEL will bediscussed.