Water-Splitting Chemistry of Photosystem II

To understand the wear-splitting chemistry of enzyme photosystem II (PSII), researchers have sought insights from a great number of different sorts of experiments all directed both at the protein and at model metal complexes. Sophisticated spectroscopic techniques such as EPR (electron paramagnetic resonance), FTIR (Fourier transform infrared) and XAS (X-ray absorption spectroscopy) as well as time-resolved mass spectrometry have been deployed against the OEC (oxygen evolving complex), yielding for the first time detailed information in a variety of S-states. The recent crystallographic studies have made it possible to propose and to test more detailed mechanistic proposals than have previously been tenable.