Femtosecond pump - probe spectroscopy reveals the photo-excited state and charge transfer of a photocatalytic metal-organic framework

With femtosecond pump-probe spectroscopy we found for photocatalytically active NH2-MIL-125 that after photo-excitation the hole resides on -NH2. Charge transfer from the MOF to an occluded molecule capable to shuttle single charges to a reaction centre is extremely fast (< 200 fs) while charge recombination only occurs on the ns-μs time scale.