Important step in imitating photosynthesis unraveled at FELIX Laboratory

Researchers at Radboud University’s FELIX Laboratory were able to directly diagnose the dissociation of water on the surface of a manganese oxide cluster: a close mimic of the center of the protein responsible for photosynthesis in biological systems. Angewandte Chemiepublished their collaborative results on October 23.

The Oxygen-evolving complex (OEC) is a key enzyme in photosynthesis in biological systems. OEC is a biocatalyst which splits water with the help of absorbed sunlight. This process takes place on the surface of calcium-manganese oxide clusters in the centre of OEC. A team of researchers from the University of Ulm, the Georgia Institute of Technology and Radboud University have mimicked the OEC and its interaction with water molecules in the lab and investigated the products that were formed.

Cluster transformation

Joost Bakker, researcher at Radboud University’s FELIX Laboratory explains: ‘What’s very nice is that we could show that the bare cluster, which does not look like the OEC, transforms into a shape that is very similar to the OEC in the presence of water. The cluster is able to dissociate several water molecules, which is an important prerequisite for water splitting. This shows that the water dissociation capacity is an inherent property of the cluster itself, and that it is independent of its complex protein surrounding.’

These results offer possibilities to eventually imitate the full photosynthesis process in the laboratory. ‘But we’re far from ready for that’, according to Bakker. ‘This is a first step in bio-inspired research that aims to mimic the processes that biology offers us.’

The new FELIX Laboratory at Radboud University was essential for the current publication. It gave the researchers the possibility to investigate the molecular level structure of the manganese oxide clusters in the presence of water molecules in full detail.

On October 30, 2015, the FELIX Laboratory was officially opened by Sander Dekker – State Secretary for Education, Culture and Science. At the heart of the FELIX Laboratory are three free-electron lasers that produce very intense, short-pulse infrared and terahertz (THz) light. The interaction of this light with molecules and materials provides unique information about the 3D structure, electronic properties and dynamics of matter.

Publication
‘The Interaction of Water with Free Mn4O4+ Clusters: Deprotonation and Adsorption-Induced structural Transformations’
Sandra M. Lang,* Thorsten M. Bernhardt, Denis M. Kiawi, Joost M. Bakker,* Robert N. Barnett, and Uzi Landman*
Angewandte Chemie; DOI: 10.1002/anie.201506294

More information? Contact:
Dr. Joost Bakker
j.bakker@science.ru.nl