PhD-student: Femtosecond study of molecular cages and photocatalytic water splitting

Molecular cages are self-organizing supramolecular systems that act as molecular sieves, allowing specific molecules/ions to enter the cage while blocking most other molecules and ions. This selectivity is of crucial importance in catalysis. Up to now, the molecular-scale structure and dynamics of molecular cages are not well understood. For instance, there are indications that these cages can contain highly organized water molecules that may play an important role in the selectivity of the molecular cage, for instance in the binding of the molecule/ion that enters the cage.

In this project you will study the structural dynamics of molecular cages using femtosecond two-dimensional infrared spectroscopy, probing the vibrations of the organic molecules and water molecules constituting the cage. In addition, you will study the dynamics of the cage following excitation of a photo-active molecule connected or embedded in the cage, using femtosecond visible/UV pump – infrared probe spectroscopy. These photo-active molecules will include photosensitizers and photocatalystst, for instance hydrogenase catalysts that reduce protons to hydrogen gas. At present several examples of hydrogenases exist, but they are quite unstable and their efficiency is low. We will investigate to which extent the embedding of a hydrogenase photocatalyst in a molecular cage can lead to stabilization (protection) of the photocatalyst and to an increase of the efficiency of hydrogen generation. In this project we will collaborate with the groups of Prof. dr. J. Reek and Prof. dr. S. Woutersen of the University of Amsterdam.