Ionic Liquid-Based Microemulsions in Catalysis

The design and properties of surface-active ionic liquids that are able to form stable microemulsions with heptane and water are presented, and their promise as reaction media for thermomorphic palladium-catalyzed cross-coupling reactions is demonstrated

Anti-inflamatório choline based ionic liquids: Insights into their lipophilicity, solubility and toxicity parameters

The impact on in vivo efficacy and safety of two novel ionic liquids based on the association of choline with nonsteroidal anti-inflammatory drugs, ketoprofen and naproxen forming IL-APIs, was evaluated. Their lipophilicity, solubility and toxicity were assessed aiming the illustration of the pharmaceutical profile and potential toxic impact. Partition coefficientwas determined usingmicelles of hexadecylphosphocholine and UV–Vis derivative spectroscopy. Additionally, solubility in phosphate buffer pH 7.4 wasmeasured using amodified shake flaskmethod and UV–Vis spectroscopy as detection technique. Ultimately, toxicity was considered resorting to a fully automated cytochrome c oxidase assay based onmicrofluidics. The obtained results demonstrated that the IL-APIs' drug format has the ability to interact with biological membranes and also improves solubility up to 58 times. Moreover, it was evidenced that, although being a nutrient, choline influences the IL-APIs' toxicity. The studied anti-inflammatory IL-APIs exhibited promising properties regarding their incorporation in pharmaceutical formulations

Anti-inflammatory choline based ionic liquids: Insights into their lipophilicity, solubility and toxicity parametrites

The impact on in vivo efficacy and safety of two novel ionic liquids based on the association of choline with nonsteroidal anti-inflammatory drugs, ketoprofen and naproxen forming IL-APIs, was evaluated. Their lipophilicity, solubility and toxicity were assessed aiming the illustration of the pharmaceutical profile and potential toxic impact. Partition coefficientwas determined usingmicelles of hexadecylphosphocholine and UV–Vis derivative spectroscopy. Additionally, solubility in phosphate buffer pH 7.4 wasmeasured using amodified shake flaskmethod and UV–Vis spectroscopy as detection technique. Ultimately, toxicity was considered resorting to a fully automated cytochrome c oxidase assay based onmicrofluidics. The obtained results demonstrated that the IL-APIs' drug format has the ability to interact with biological membranes and also improves solubility up to 58 times. Moreover, it was evidenced that, although being a nutrient, choline influences the IL-APIs' toxicity. The studied anti-inflammatory IL-APIs exhibited promising properties regarding their incorporation in pharmaceutical formulations

Age Determination of Six Intermediate-age SMC Star Clusters with HST/ACS

We present a photometric analysis of the star clusters Lindsay 1, Kron 3, NGC339, NGC416, Lindsay 38, and NGC419 in the Small Magellanic Cloud (SMC), observed with the Hubble Space Telescope Advanced Camera for Surveys (ACS) in the F555W and F814W filters. Our color magnitude diagrams (CMDs) extend ~3.5 mag deeper than the main-sequence turnoff points, deeper than any previous data. Cluster ages were derived using three different isochrone models: Padova, Teramo, and Dartmouth, which are all available in the ACS photometric system. Fitting observed ridgelines for each cluster, we provide a homogeneous and unique set of low-metallicity, single-age fiducial isochrones. The cluster CMDs are best approximated by the Dartmouth isochrones for all clusters, except for NGC419 where the Padova isochrones provided the best fit. The CMD of NGC419 shows several main-sequence turn-offs, which belong to the cluster and to the SMC field. We thus derive an age range of 1.2-1.6 Gyr for NGC419. Interestingly, our intermediate-age star clusters have a metallicity spread of ~0.6 dex, which demonstrates that the SMC does not have a smooth, monotonic age-metallicity relation. We find an indication for centrally concentrated blue straggler star candidates in NGC416, while for the other clusters these are not present. Using the red clump magnitudes, we find that the closest cluster, NGC419 (~50kpc), and the farthest cluster, Lindsay 38 (~67kpc), have a relative distance of ~17kpc, which confirms the large depth of the SMC.Comment: 25 pages, 45 Figure

Chiral and metal functionalized ionic liquids in organic synthesis

Zsfassung in dt. SpracheIm Rahmen dieser Dissertation wurden verschieden Synthesewege zur Herstellung von neuen chiralen ionischen Flüssigkeiten entwickelt und deren Anwendung untersucht. Ausgehend von Campher-Derivaten konnten chirale ionische Flüssigkeiten als neuartige Reaktionsmedien für die stereoselektive Diels-Alder Reaktionen synthetisiert werden. Neue chirale ionische Flüssigkeiten mit Amidoalkohol-Struktur konnten als chirale Shiftreagenzien zur Bestimmung des Enantiomerenüberschusses von racemischen Salzen entwickelt werden. Weiters wurden basische ionische Flüssigkeiten aus chiralen Aminoalkoholen synthetisiert, die erfolgreich in der asymmetrischen Alkylierung von Aldehyden eingesetzt wurden und Enantioselektivitäten von bis zu 95% ee ermöglichten.Im zweiten Teil dieser Arbeit wurden metallhältige ionische Flüssigkeiten auf ihr Katalysevermögen untersucht. Dabei gelang es, die eisenhältige ionische Flüssigkeit 1-Butyl-3-methylimidazolium tetrachloroferrat (bmim-FeCl4) als neuen und effizienten Katalysator für Kumada-Kreuzkupplungen zu etablieren. Auch der Einsatz dieser ionischen Flüssigkeit in der eisenkatalysierten Michael-Addition unter Mikrowellen-Bedingungen und in Hydroxymethylierungen in wässrigen Systemen konnte erfolgreich durchgeführt werden und zeigte deutliche Vorteile zu konventionellen Katalysatoren.The design, synthesis and application of various chiral ionic liquids derived from chiral-pool components was investigated. Starting from camphor derivatives, chiral ionic liquids that could be used as alternative reaction media for the stereoselective Diels-Alder reaction were developed. New chiral ionic liquids with amido alcohol structure could be successfully applied as chiral shift reagents for the determination of enantiomeric excess of racemic salts. Furthermore, basic amino alcohol-derived ionic liquids were successfully applied as catalysts in the asymmetric alkylation of aldehyds and gave high enantioselectivities of up to 95% ee.In the second part, the application of metal-containing ionic liquids as recyclable catalysts for C-C bond formation besides their application as mere reaction media was investigated.The iron-containing ionic liquid butylmethylimidazolium tetrachloroferrate (bmim-FeCl4) could be established as efficient and recyclable catalyst for biphasic Kumada-Corriu cross-coupling. Additionally, this ionic liquid was successfully applied in the iron-catalyzed Michael addition under microwave conditions as well as in hydroxymethylation in aqueous systems. In each case, the concept of metal-containing ionic liquid catalysts worked exceptionally well and showed several advantages compared to conventional catalysts.19

Hydration and Counterion Binding of [C12MIM] Micelles

The final publication is available via https://doi.org/10.1021/acs.langmuir.7b02201.Surface-active ionic liquids based on imidazolium cations are promising targets for micellar catalysis in aqueous solution, yielding enhanced rate constants compared to surfactants based on n-alkyltrimethylammonium cations and exhibiting a pronounced counterion dependence (Bica Chem. Commun. 2012, 48, 5013−5015; Cognigni Phys. Chem. Chem. Phys. 2016, 18, 13375–13384). Probably most relevant to these effects is the interplay between headgroup hydration and counterion binding. To obtain more detailed information on these effects, aqueous solutions of 1-dodecyl-3-methylimidazolium ([C12MIM]) bromide, iodide, and triflate (TfO–) were investigated at 45 °C using broadband dielectric spectroscopy, viscosity measurements, and small-angle X-ray scattering experiments. Effective hydration numbers were determined, and information on the locations and mobilities of the condensed counterions, X–, was derived. It was found that [C12MIM] halide micelles were less hydrated than the corresponding n-dodecyltrimethylammonium ([C12TA]X) aggregates. Together with their somewhat weaker counterion condensation, this difference probably explains their higher catalytic activity. Whereas [C12MIM]Br micelles remained roughly spherical in the studied concentration range, rodlike aggregates were formed at high concentrations of the iodide and, in particular, the triflate surfactants. It appears that the much lower mobility of condensed TfO– counterions is the reason for the very low catalytic activity of [C12MIM]TfO micelles.Austrian Science Funds (FWF)COST action , Exchange on Ionic LiquidsDFG Graduate School GRKBayerisch-französisches Hochschulzentrum (BFHZ

Surface-active Ionic Liquids for Micellar Extraction of Piperine from Black Pepper

The final publication is available via https://doi.org/10.5560/znb.2013-3196.We present the application of ionic liquid-aqueous micellar solutions as isolation media for the pharmaceutically active ingredient piperine from black pepper. Several surface-active ionic liquids including a biodegradable betaine derivative were used for the extraction of piperine, and a strong correlation between extraction yield and the critical micelle concentration of the respective ionic liquid was found. A scaled strategy for the isolation of piperine was developed that allowed recovery and recycling of the aqueous ionic liquid micellar solution for five runs without any loss in extraction efficiency