Photodissociation

Under photolysis or photolysis refers generally to the cleavage of a molecule, such as the irradiation with light. This is determined by the strength of the chemical bond to be solved, which wavelength the incident light may have a maximum in order to muster enough energy can cleave this bond. Electromagnetic wave, the lower the wavelength, the higher is the energy that can be transmitted per photon / energy quantum.

The part of the field of chemistry that deals with reactions initiated by light, ie photochemistry.

Photolysis of water in oxygenic photosynthesis

Of particular importance is the splitting of water by light. It takes place in the context of oxygenic photosynthesis. The specificity of this reaction in the context of photosynthesis is that it is not triggered by the direct irradiation of the water (the energy of visible light is responsible for the splitting of water too low), but runs within the so-called water splitting complex, which is part of photosystem II is. Manganese ions in doing so appear to play a crucial role. A manga stabilizing protein shields a manganese cluster of four manganese ions from the thylakoid interior. The manganese ions are able to save four electrons, but these give off again and have to go through the splitting of water (more precisely, by oxidation of two water molecules ) supply with 4 new electrons. In simplified terms, the following reaction takes place at the photolysis takes: