Synthesis of red-emitting fluorophores

Understanding the mechanism of action of biologically active compounds is of great interest in medicine, including cancer research. Chemical labeling of molecules, i.e. making them "visible" under the right conditions, is a widespread and intensively researched field of science. The fluorescent labeling of compounds offers several advantages over other methods. It might be considered as an environmentally friendly alternative to radioisotope labeling. It is highly important that fluorophores used in biomedical applications meet certain criteria, including high photostability, good cell permeability and stability under physiological conditions. However, the accessibility of the fluorophores is often limited owing to their high price and complex synthetic strategies. Here we synthesized aza-BODIPY fluorophores, which are red-emitting altervatives to BODIPY derivatives. The syntheses were carried out considering the principles of green chemistry. One-pot and/or microwave-assisted syntheses were performed in order to minimize the number of reaction steps and time and use of solvents

Application of high power UV LEDs in heterogeneous photocatalysis

In our work, we designed and built a photochemical reactor with High Power LED light sources, and then tested its operation by heterogeneous photocatalytic decomposition of coumarin. The UV-LEDs emitting at a wavelength of 367(±10) nm were built into a frame with air-cooling elements. A well-controlled electrical power source was used to control and regulate the light output of the LEDs. The photon flux was measured at different electric power inputs, and was found to be linearly dependent on electrical power. Coumarin was used to test the new photoreactor during heterogeneous photocatalysis using TiO2 and ZnO as photocatalysts. At low photon flux the UV-LEDs outperformed a fluorescent mercury-vapor lamp in terms of efficiency and power consumption, but their usage at high electric input is not favorable

BiOCl/BiOI composit photocatalysts - investigation of their efficiency using UV and visible led light sources

Due to its unique layered structure, bismuth oxyhalide (BiOX, where X=F, Cl, Br, I) has potential applications as a photocatalytic material in clean energy utilization and environmental purification. In this work, BiOI, BiOCl, and their composites with various BiOI:BiOCl molar ratios were synthesized and characterized for their heterogeneous photocatalytic applications. The methyl orange was used as a model pollutant and UV and visible LED light sources were applied. Adsorption measurements and photocatalytic tests proved that, the BiOI/BiOCl composite, which contains 80% BiOI and 20% BiOCl, showed the best activity. The composite catalyst showed good activity under visible light and was particularly better than pure BiOI and BiOCl under UV radiation. The transformation mechanism of methyl orange is initiated by direct charge transfer processes, via photosensitization