OLEDs as prospective light sources for microstructured photoreactors
In this work, the use of OLEDs as light sources to initiate photochemical reactions is presented for the first time. A newly developed modular photoreactor system utilising microstructured reactors was equipped with commercially available OLED panels. The technical feature of being a surface emitter, the low thickness and the potentially high luminescent efficiency give reason to expect this kind of light source to be well suited for photochemical reactions. The reactor system was investigated by using photooxygenations as benchmark reactions. In detail, photosensitised [4 + 2]-cycloadditions and [2 + 2]-cycloadditions of 1O2 were examined as well as Schenck-ene-reactions. It was demonstrated that OLEDs can be successfully used for conducting photochemical reactions. Moreover the equilibrium concentration of 1O2 can be increased by varying the process conditions. Based on the experimental investigations, a reactor comparison showed that, with respect to productivity and efficiency, the investigated microstructured photoreactor is currently not outperforming conventional batch reactors.