A5032466321- Inorganic Fluorides and Related Compounds
- X-ray Diffraction in Crystallography
- Inorganic Chemistry and Materials
- Crystallization and Solubility Studies
- Luminescence Properties of Advanced Materials
- Advanced Chemical Physics Studies
- Advanced NMR Techniques and Applications
- Crystallography and molecular interactions
- Glass properties and applications
- Crystal Structures and Properties
- Solid-state spectroscopy and crystallography
- Fluorine in Organic Chemistry
- Metal-Organic Frameworks: Synthesis and Applications
- Magnetism in coordination complexes
- Advanced Condensed Matter Physics
- Layered Double Hydroxides Synthesis and Applications
- Methane Hydrates and Related Phenomena
- Muon and positron interactions and applications
- Ammonia Synthesis and Nitrogen Reduction
- Catalysis and Oxidation Reactions
- Synthesis and characterization of novel inorganic/organometallic compounds
- Mineralogy and Gemology Studies
- Catalytic Processes in Materials Science
- Zeolite Catalysis and Synthesis
- Advanced ceramic materials synthesis
Humboldt-Universität zu Berlin
2014-2023
Merck (Germany)
2015
Federal Institute For Materials Research and Testing
2008-2009
Max Planck Institute for Polymer Research
2009
Leipzig University
2002-2009
Max Planck Institute of Colloids and Interfaces
2007-2008
University of Toronto
2007
Humboldt State University
2004-2005
Le Mans Université
2003
Centre National de la Recherche Scientifique
2003
'Al'l about F: Aluminum chlorofluoride (ACF) catalyzes the hydrodefluorination, as well Friedel–Crafts reactions of fluorinated methanes in presence Et3SiH. A surface-bound silylium-ion-like species is considered to be a crucial intermediate achieving CF bond cleavage.
Abstract Niobium pentoxides are promising acid catalysts for the conversion of biomass into fuels and chemicals. Developing new synthesis routes is essential designing niobium pentoxide with improved activity specific practical processes. Here we show a approach in acetophenone, which produces nanostructured varying structure acidity that act as efficient catalysts. The oxides have orthorhombic structures different extents distortions coordinatively unsaturated metal atoms. A strong...
Novel magnesium fluorides have been prepared by a new fluorolytic sol-gel synthesis for fluoride materials based on aqueous HF. By changing the amount of water at constant stoichiometric HF, it is possible to tune surface acidity resulting partly hydroxylated fluorides. These possess medium-strength Lewis acid sites and, increasing water, Brønsted as well. Magnesium hydroxyl groups normally basic nature and only with this synthetic route create acidic groups. XRD, MAS NMR, TEM, thermal...
Summary Chemical and mineralogical analyses of two representative laterite profiles developed from granite in south‐western Australia have shown that several depth zones defined by particular mineral suites geochemistry may be recognized. These are not simply related to the conventional morphological pallid, mottled, ferruginous zones. Changes both can stability major species common isomorphous substitutions occurring them. Ca, Na, Mg, which mainly present plagioclase feldspars...
A series of niobium-modified aluminum hydroxide fluorides (denoted Nb@AlF3), prepared via a fluorolytic sol–gel synthesis was investigated for the catalytic one-pot conversion cellulose to lactic acid. The structure new acid catalysts is result dispersion niobium fluoride in an matrix. calcination at relatively low temperature (350 °C) stabilized this structure. Catalytic performances terms yields are directly correlated with content.
Ionic conductivity is ubiquitous to many industrially important applications such as fuel cells, batteries, sensors, and catalysis. Tunable in these systems therefore key their commercial viability. Here, we show that geometric frustration can be exploited a vehicle for tuning. In particular, imposed upon prototypical system, CaF2, by ball milling it with BaF2, create nanostructured Ba1–xCaxF2 solid solutions increased its ionic over 5 orders of magnitude. By mirroring each experiment MD...
A universal fast and easy access at room temperature to transparent sols of nanoscopic Eu3+ Tb3+ doped CaF2, SrF2 BaF2 particles via the fluorolytic sol-gel synthesis route is presented. Monodisperse quasi-spherical nanoparticles with sizes 3-20 nm are obtained up 40% rare earth doping showing red or green luminescence. In beginning luminescence quenching effects only observed for highest content, which demonstrates unique outstanding properties these materials. From CaF2:Eu10 SrF2:Eu10...
Small but important: the kind of solvent added in liquid-assisted grinding syntheses cocrystals influences final product and reaction rate.
The structure of the very strong solid Lewis acid aluminum chlorofluoride (ACF, AlCl(x)F(3-x), x = 0.05-0.3) was studied by IR, ESR, Cl K XANES, (19)F MAS NMR, and (27)Al SATRAS NMR spectroscopic methods compared with amorphous fluoride conventionally prepared dehydration alpha-AlF(3) 3H(2)O. thermal behavior both compounds investigated DTA XRD. In comparison to ACF, AlF(3) in a conventional way is not catalytically active for isomerization reaction 1,2-dibromohexafluoropropane, which...
Amine-functionalized, chiral mesoporous organosilicas were prepared from a rationally designed precursor, which combines the functions of network builder, latent functional group, and porogen in one molecule. The precursors are formed by convenient enantioselective hydroboration using (S)-monoisopinocampheylborane on an ethylene-bridged silica precursor. These do self-organize when hydrolysis their inorganic moiety takes place via aggregation organic into hydrophobic domains. After...
Aluminiumchlorofluorid (ACF) katalysiert die Hydrodefluorierung sowie Friedel-Crafts-Reaktionen von fluorierten Methanen in der Gegenwart Et3SiH. Eine oberflächengebundene Silyliumion-artige Spezies wird als das Schlüsselintermediat C-F-Bindungsspaltung vermutet.
The structure and the formation pathway of a new theobromine : oxalic acid (2 1) cocrystal are presented.
New fluorinated alkaline earth metal–organic frameworks were successfully synthesized by milling of metal hydroxides M(OH)2 with tetrafluoroterephthalic acid H2pBDC-F4. Both calcium- and strontium-tetrafluoroterephthalates are tetrahydrated, while the barium tetrafluoroterephthalate is free coordinating water molecules. The two isomorphic structures Ca(pBDC-F4)·4H2O Sr(pBDC-F4)·4H2O solved from powder diffraction data ab initio structure determination subsequent Rietveld refinement. products...
Nanostructured Al2O3 powders were prepared by high-energy ball milling of corundum. Both the solid state nuclear magnetic resonance spectra Al3+ ions and electron paramagnetic incorporated Fe3+ are governed noticeable spectral changes dependent on duration mechanical treatment. The quadrupolar parameters 27Al nuclei zero-field splitting as well their statistical distributions determined functions time. Structural matrix also followed powder x-ray diffraction transmission microscopy...
High surface area MgF2 was prepared by the sol–gel technique from magnesium alkoxides. The influence of different ratios Mg(OCH3)2 to HF, alkoxides, catalysts, solvents as well aging times investigated. XRD, MAS-NMR, FT-IR, thermal analysis and elemental were applied study structure, composition behaviour bulk materials. determination properties accomplished with N2 Ar adsorption–desorption isotherms.
The thermal treatment of sol−gel derived aluminum hydroxide fluorides leads to new, X-ray amorphous, macroporous oxide-hydroxide fluorides. Followed by EA, DTA-TG, XPS, FT-IR, NH3-TPD, BET, XRD, and MAS NMR, it can be shown that the simplified composition these compounds is "AlFO" "AlF2O1/2", respectively. These exhibit a large number acid centers. local structure consists AlFxOcn-x units (cn, coordination numbers 6, 5, 4), all sites are partially fluorinated. It bridged terminal F-sites...
A new synthesis route to nonhydrated, X-ray amorphous aluminum hydroxy fluorides was explored by sol−gel with aqueous hydrofluoric acid. Followed XRD, MAS NMR, and DTA-TG, it can be shown that the product composition after thermal annealing critically depends on gaseous atmosphere. Dependent fluorine content, corundum formation occur at temperatures as low 900 °C. Additional mechanical activation of starting material enhances effects pyrohydrolysis consequently favors early in addition.