15 research outputs found

    (Picolinato-κ2 N,O)[tris(2-isopropyl-1H-imidazol-4-yl-κN 3)phosphane]cobalt(II) nitrate

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    Single crystals of the title compound, [Co(C6H4NO2)(C18H27N6P)]NO3, were obtained from the reaction of nitrato[tris­(2-isopropyl­imidazol-4-yl)phosphane]cobalt(II) nitrate with picolinic acid in the presence of potassium tert-butoxide as base. The coordination polyhedron around the central CoII ion is about halfway between square-pyramidal and trigonal-bipyramidal geometry. In the structure, the nitrate counter-anion is connected by N—H⋯O hydrogen bonding to the complex cation. Additionally, the complex cations form one-dimensional chains along [010] by hydrogen bonding of the NH group of an imidazole ring to the picolinate group of a neighbouring complex cation

    Do biotransformation data from laboratory experiments reflect micropollutant degradation in a large river basin?

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    Identifying a chemical's potential for biotransformation in the aquatic environment is crucial to predict its fate and manage its potential hazards. Due to the complexity of natural water bodies, especially river networks, biotransformation is often studied in laboratory experiments, assuming that study outcomes can be extrapolated to compound behavior in the field. Here, we investigated to what extent outcomes of laboratory simulation studies indeed reflect biotransformation kinetics observed in riverine systems. To determine in-field biotransformation, we measured loads of 27 wastewater treatment plant effluent-borne compounds along the Rhine and its major tributaries during two seasons. Up to 21 compounds were detected at each sampling location. Measured compound loads were used in an inverse model framework of the Rhine river basin to derive k’bio,field values – a compound-specific parameter describing the compounds’ average biotransformation potential during the field studies. To support model calibration, we performed phototransformation and sorption experiments with all the study compounds, identifying 5 compounds that are susceptible towards direct phototransformation and determining Koc values covering four orders of magnitude. On the laboratory side, we used a similar inverse model framework to derive k’bio,lab values from water-sediment experiments run according to a modified OECD 308-type protocol. The comparison of k’bio,lab and k’bio,field revealed that their absolute values differed, pointing towards faster transformation in the Rhine river basin. Yet, we could demonstrate that relative rankings of biotransformation potential and groups of compounds with low, moderate and high persistence agree reasonably well between laboratory and field outcomes. Overall, our results provide evidence that laboratory-based biotransformation studies using the modified OECD 308 protocol and k’bio values derived thereof bear considerable potential to reflect biotransformation of micropollutants in one of the largest European river basins

    Energy down converting organic fluorophore functionalized mesoporous silica hybrids for monolith-coated light emitting diodes

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    The covalent attachment of organic fluorophores in mesoporous silica matrices for usage as energy down converting phosphors without employing inorganic transition or rare earth metals is reported in this article. Triethoxysilylpropyl-substituted derivatives of the blue emitting perylene, green emitting benzofurazane, and red emitting Nile red were synthesized and applied in the synthesis of mesoporous hybrid materials by postsynthetic grafting to commercially available MCM-41. These individually dye-functionalized hybrid materials are mixed in variable ratios to furnish a powder capable of emitting white light with CIE chromaticity coordinates of x = 0.33, y = 0.33 and an external quantum yield of 4.6% upon irradiation at 410 nm. Furthermore, as a proof of concept two different device setups of commercially available UV light emitting diodes, are coated with silica monoliths containing the three triethoxysilylpropyl-substituted fluorophore derivatives. These coatings are able to convert the emitted UV light into light with correlated color temperatures of very cold white (41100 K, 10700 K) as well as a greenish white emission with correlated color temperatures of about 5500 K

    Multimodality Imaging of Silica and Silicon Materials In Vivo

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    Abstract Recent progress in the development of silica? and silicon?based multimodality imaging nanoprobes has advanced their use in image?guided drug delivery, and the development of novel systems for nanotheranostic and diagnostic applications. As biocompatible and flexibly tunable materials, silica and silicon provide excellent platforms with high clinical potential in nanotheranostic and diagnostic probes with well?defined morphology and surface chemistry, yielding multifunctional properties. In vivo imaging is of great value in the exploration of methods for improving site?specific nanotherapeutic delivery by silica? and silicon?based drug?delivery systems. Multimodality approaches are essential for understanding the biological interactions of nanotherapeutics in the physiological environment in vivo. The aim here is to describe recent advances in the development of in vivo imaging tools based on nanostructured silica and silicon, and their applications in single and multimodality imaging.Peer reviewe
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