Leuchtdioden in der Chemie – Eine Hochzeit verschiedener Technologien

Assessing photochemistry as a green synthetic method. Carbon–carbon bond forming reactions

“…The last point will be considered in a forthcoming study (notice however that a considerable improvement of this point comes from the use of LEDs; as a further advantage, these are available with a short l range emission, allowing to choice the best match between source and reagent absorption). 52 From the present work, it can be concluded that the large amount of photochemical syntheses reported in the literature, and in particular the C-C bond forming reactions discussed here, require further elaboration for being considered satisfactory from the environmental point of view. However, the changes to be made are identified by the EATOS analysis and once that these are applied the environment-friendly character of these reactions becomes apparent.…”

Flow photochemistry: Old light through new windows

“…It was shown that Rose Bengal was approximately twice as effective a sensitiser as Ru( t -bpy) 3 Cl 2 when a 450 W Xe lamp was employed. Through the use of an LED light source in the microreactor, the authors reported that the microflow system was slightly superior to the batch-type Schlenk reactor in terms of space–time turnovers and photon efficiency; however, the required 400 min irradiation to achieve reasonable conversion on a 1 mmol scale would likely cause difficulty in finding synthetic utility for the reactor [33–34]. It is also interesting to compare the efficiency of the reactor with that of alternatives; despite the reported high photon efficiency, an LCE comparison [35] of six methods for the conversion of β-citronellol into rose oxide showed the above method to be less competitive, mainly due to the long irradiation times causing high consumption of electrical power.…”

On the electronic structure of nitro-substituted bipyridines and their platinum complexes

“…Reported applications for charge transfer complexes of 2,2¢bipyridine (bipy) include chemodosimetry, 1 hydrogen production by artificial photosynthesis, 2,3 and dye sensitised solar cells. [4][5][6][7][8][9] We have been probing the electronic structure, and the nature of the important charge transfer excited states, in such species by electrochemical techniques coupled with UV/Vis and EPR spectroscopies, focusing in particular on the family of square planar platinum(II) complexes. 10- 12 Recently, we have investigated the effects of strongly electron withdrawing groups on the bipyridyl, for example, in 4-NO 2 -bipy.…”