TY - JOUR A1 - Usmani, Shirin A1 - Stephan, Ina A1 - Huebert, Thomas A1 - Kemnitz, E. T1 - Nano metal fluorides for wood protection against fungi N2 - Wood treated with nano metal fluorides is found to resist fungal decay. Sol−gel synthesis was used to synthesize MgF2 and CaF2 nanoparticles. Electron microscopy images confirmed the localization of MgF2 and CaF2 nanoparticles in wood. Efficacy of nano metal fluoride-treated wood was tested against brown-rot fungi Coniophora puteana and Rhodonia placenta. Untreated wood specimens had higher mass losses (∼30%) compared to treated specimens, which had average mass loss of 2% against C. puteana and 14% against R. placenta, respectively. Nano metal fluorides provide a viable alternative to current wood preservatives. KW - Brown-rot fungi KW - Coniophora puteana KW - Fluoride nanoparticles KW - Fluorolytic sol−gel KW - Rhodonia placenta KW - SEM wood characterization KW - Wood protection PY - 2018 DO - https://doi.org/10.1021/acsanm.8b00144 SN - 2574-0970 VL - 2018 SP - 1 EP - 6 PB - American Chemical Society (ACS) CY - Washington DC, US AN - OPUS4-44730 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Breitfeld, Steffen A1 - Scholz, G. A1 - Emmerling, Franziska A1 - Kemnitz, E. T1 - BaF-benzenedicarboxylate: the first mechanochemical N2 - Anewbariumcoordination polymer, BaF-benzenedicarboxylate (BaF(p-BDC)0.5), with fluorine directly coordinated to the metal cation, was prepared by mechanochemical synthesis routes. Phase-pure BaF-benzenedicarboxylate was synthesized by milling starting either from barium hydroxide or from Barium acetate as sources for barium cations. In both cases, the second reactant was 1,4-benzenedicarboxylic acid (H2(p-BDC)). Ammonium fluoride was used as fluorinating agent directly at milling. This is the first mechanochemical synthesis of coordination polymers where fluorine is directly coordinated to the metal cation. Following the second possibility, barium acetate fluoride (Ba(OAc)F) is formed as ntermediate product after milling, and the new coordination polymer is accessible only after washing with water and dimethyl sulfoxide. The new compound BaF(p-BDC)0.5 was characterized by X-ray powder diffraction, FTIR-, and 19F, 1H-13C CP MAS NMR spectroscopies, DTA-TG, and elemental Analysis. KW - Milling KW - MOF PY - 2018 DO - https://doi.org/10.1007/s10853-018-2331-3 SN - 0022-2461 VL - 53 IS - 19 SP - 13682 EP - 13689 PB - Springer AN - OPUS4-45677 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Usmani, S. A1 - Voss, L. A1 - Stephan, Ina A1 - Hübert, Thomas A1 - Kemnitz, E. T1 - Improved Durability of Wood Treated with Nano Metal Fluorides against Brown-Rot and White-Rot Fungi N2 - Low-water soluble metal fluorides such as magnesium fluoride (MgF2) and calcium Fluoride (CaF2) were evaluated for decay protection of wood. Initially, the biocidal efficacy of nano metal fluorides (NMFs) against wood destroying fungi was assessed with an in-vitro agar test. The results from the test showed that agar medium containing MgF2 and CaF2 was more efficient in preventing fungal decay than stand-alone MgF2 or CaF2. These metal fluorides, in their nanoscopic form synthesized using fluorolytic sol-gel synthesis, were introduced into the sapwood of Scots pine and beech wood and then subjected to accelerated ageing by leaching (EN 84). MAS 19F NMR and X-ray micro CT images showed that metal fluorides were present in treated wood, unleached and leached. Decay resistance of Scots pine and beech wood treated with NMFs was tested against Wood destroying fungi Rhodonia placenta and Trametes versicolor in accordance with EN 113. Results revealed that mass losses were reduced to below 3% in wood treated with the combination of MgF2 and CaF2. It is concluded that NMFs provide full protection to wood even after it has been leached and can be used as wood preservatives in outdoor environments. KW - Nanoparticles KW - Fluoride KW - Wood protection KW - Fluorolytic sol-gel synthesis KW - Brown-rot fungi KW - White-rot fungi KW - Basidiomycetes PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543877 DO - https://doi.org/10.3390/app12031727 VL - 12 IS - 3 SP - 1 EP - 11 PB - MDPI AN - OPUS4-54387 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Guo, Y. A1 - Lippitz, Andreas A1 - Saftien, P. A1 - Unger, Wolfgang A1 - Kemnitz, E. T1 - Tuning the surface properties of novel ternary iron(III) fluoride-based catalysts using the template effect of the matrix N2 - Sol–gel prepared ternary FeF3–MgF2 materials have become promising heterogeneous catalysts due to their porosity and surface Lewis/Brønsted acidity (bi-acidity). Despite the good catalytic performance, nanoscopic characterisations of this type of material are still missing and the key factors controlling the surface properties have not yet been identified, impeding both a better understanding and further development of ternary fluoride catalysts. In this study, we characterised the interaction between the bi-acidic component (FeF3) and the matrix (MgF2) on the nano-scale. For the first time, the formation pathway of FeF3–MgF2 was profiled and the template effect of MgF2 during the synthesis process was discovered. Based on these new insights two novel materials, FeF3–CaF2 and FeF3–SrF2, were established, revealing that with decreasing the atomic numbers (from Sr to Mg), the ternary fluorides exhibited increasing surface acidity and surface area but decreasing pore size. These systematic changes gave rise to a panel of catalysts with tuneable surface and bulk properties either by changing the matrix alkaline earth metal fluoride or by adjusting their ratios to Fe or both. The template effect of the alkaline earth metal fluoride matrix was identified as the most probable key factor determining the surface properties and further influencing the catalytic performance in ternary fluoride based catalysts, and paves the way to targeted design of next-generation catalysts with tunable properties. KW - Catalysis KW - Surface analysis KW - XPS PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-327410 DO - https://doi.org/10.1039/c4dt03229b SN - 1477-9226 SN - 1477-9234 SN - 1364-5447 VL - 44 IS - 11 SP - 5076 EP - 5085 PB - RSC CY - Cambridge AN - OPUS4-32741 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meißner, G. A1 - Dirican, D. A1 - Jäger, Christian A1 - Braun, T. A1 - Kemnitz, E. T1 - Et3GeH versus Et3SiH: controlling reaction pathways in catalytic C–F bond activations at a nanoscopic aluminum chlorofluoride† N2 - Catalytic C–F bond activation reactions of mono- and polyfluoroalkanes at Lewis acidic amorphous aluminum chlorofluoride (ACF) are presented. The hydrogen sources Et3GeH or Et3SiH control the selectivity of the conversions. The immobilization of Et3GeH at ACF resulted in catalytic dehydrohalogenation reactions to yield olefins under very mild conditions. In contrast, if Et3SiH is immobilized at ACF, C–C coupling occured and the formation of Friedel–Crafts products was observed. MAS NMR spectroscopic studies revealed information about the surface binding of the substrates. KW - Vapor-phase hydrofluorination KW - Carbon-fluorine bonds KW - Vinyl fluoride KW - Phosphine-ligands KW - Room-temperature KW - Building-blocks KW - Etal-complexes KW - Germylium ions KW - Lewis-acids KW - Hydrodefluorination PY - 2017 DO - https://doi.org/10.1039/c7cy00845g SN - 2044-4753 SN - 2044-4761 VL - 7 IS - 15 SP - 3348 EP - 3354 PB - The Royal Society of Chemistry AN - OPUS4-41836 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Hannes A1 - Kemnitz, E. A1 - Hertwig, Andreas A1 - Beck, Uwe T1 - Transparent MgF2-films by sol-gel coating: Synthesis and optical properties N2 - Dielectric, anti-reflective or high reflective systems consist of low and high refractive index layers. Common systems are oxides. The preparation of low refractive index MgF2-films of optical quality by means of an anhydrous low temperature sol–gel synthesis is presented. The MgF2-sol is prepared by spin-coating on silicon and glass substrates. Various film thicknesses between 20 nm and 435 nm have been deposited. It has been shown that the thickness increase is proportional to the number of coating steps. The deposited MgF2-films consist of 10 nm to 20 nm large nanoparticles and have smooth surfaces with an average roughness (Ra) of (1.7 ± 0.3) nm. The optical constants n and k of the films are in agreement with the literature data of bulk-MgF2. KW - Sol-gel KW - Nano-MgF2 KW - Spin coating KW - Optical properties KW - Nanoparticles PY - 2008 DO - https://doi.org/10.1016/j.tsf.2007.10.126 SN - 0040-6090 VL - 516 IS - 12 SP - 4175 EP - 4177 PB - Elsevier CY - Amsterdam AN - OPUS4-17375 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Hannes A1 - Hertwig, Andreas A1 - Beck, Uwe A1 - Kemnitz, E. T1 - Low temperature sol-gel metal oxide and fluoride layer stacks for optical applications N2 - MgF2 and TiO2 single layers and layer stacks were produced by a spin-coating sol-gel process. The final temperature treatment was carried out at 100 °C. The layers were deposited onto silicon and fused silica substrates and were analysed by means of atomic force microscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, ellipsometry, and UV-vis transmission spectroscopy. MgF2 and TiO2 single layers have morphological and optical properties comparable with physical vapour deposited layers. By using spectroscopic mapping ellipsometry, a good inter- and intra-sample homogeneity was confirmed. Multiple deposition steps result in a linear increase of layer thickness. Various films were deposited with thicknesses between 25 nm and 350 nm. It was shown that the low temperature sol-gel process results in films of optical quality. Anti-reflective and high reflective layer stacks consisting of MgF2 and TiO2 were designed and can be produced now by a sol-gel process, whereas the MgF2 layers in the layer stacks contains also traces of MgF2-2xOx. KW - Magnesium fluoride KW - Titanium oxide KW - Sol-gel KW - Spin-coating KW - Optical properties KW - Optical layer stacks KW - MgF2 KW - TiO2 PY - 2010 DO - https://doi.org/10.1016/j.tsf.2010.06.025 SN - 0040-6090 VL - 518 IS - 21 SP - 6080 EP - 6086 PB - Elsevier CY - Amsterdam AN - OPUS4-21516 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - König, R. A1 - Scholz, G. A1 - Kemnitz, E. T1 - Crystalline aluminium hydroxy fluorides: Structural insights obtained by high field solid state NMR and 27Al chemical shift trend analysis T2 - Gesellschaft Deutscher Chemiker CY - Regensburg, Germany DA - 2008-09-22 PY - 2008 AN - OPUS4-17956 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - König, R. A1 - Scholz, G. A1 - Kemnitz, E. T1 - Crystalline aluminium hydroxyl fluorides: Structural insights obtained by high-field solid state NMR and 27Al chemical shift trend analysis T2 - Gesellschaft Deutscher Chemiker CY - Regensburg, Germany DA - 2008-09-22 PY - 2008 AN - OPUS4-17957 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Hannes A1 - Kemnitz, E. A1 - Hertwig, Andreas A1 - Beck, Uwe T1 - Moderate temperature sol-gel deposition of magnesium fluoride films for optical UV-applications: A study on homogeneity using spectroscopic ellipsometry N2 - Thin films of MgF2 have been deposited on silicon wafers in optical quality with a novel sol-gel deposition process at temperatures as low as 100 °C. The properties of the fluoride layers are compared to bulk MgF2 with respect to the optical constants. By employing spectroscopic mapping ellipsometry, the uniformity of the thickness of fluoride layers is confirmed to be within acceptable limits for optical applications. The optical constants are close to the bulk data. High-quality low-index films of suitable and homogeneous thickness have already been produced on a laboratory scale. KW - 78.20.-e KW - 78.66.Li KW - 78.68.+m KW - 81.20.Fw PY - 2008 DO - https://doi.org/10.1002/pssa.200777856 SN - 1862-6300 SN - 0031-8965 VL - 205 IS - 4 SP - 821 EP - 824 PB - Wiley-VCH CY - Berlin AN - OPUS4-17330 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kemnitz, E. T1 - Nano metal fluorides: Small size but great properties T2 - Inorganic Fluorides for Chemistry and Environment, Optics and Electronics CY - Bordeaux, France DA - 2010-04-14 PY - 2010 AN - OPUS4-20868 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - König, R. A1 - Scholz, G. A1 - Scheurell, K. A1 - Heidemann, D. A1 - Buchem, I. A1 - Unger, Wolfgang A1 - Kemnitz, E. T1 - Spectroscopic characterization of crystalline AIF3 phases N2 - A comprehensive spectroscopic characterization of all known crystalline AlF3 phases (α-, β-, η-, κ-, θ-AlF3) is presented for the first time in this study. Beside their X-ray diffraction powder patterns, which were already published in the literature, 27Al and 19F MAS NMR, FT IR and XPS spectroscopic techniques were applied for all phases in a consistent manner. For all phases prepared the utilization of 27Al satellite transition (SATRAS) NMR allowed to determine the quadrupolar parameters of the aluminium sites including their distributions. In addition, η-AlF3 was isolated with high phase purity and characterized following a new preparation path different from those known so far in the literature. KW - Crystalline aluminium fluorides KW - Solid state NMR KW - FT IR KW - XPS PY - 2010 DO - https://doi.org/10.1016/j.jfluchem.2009.10.015 SN - 0022-1139 SN - 1873-3328 VL - 131 IS - 1 SP - 91 EP - 97 PB - Elsevier CY - Amsterdam AN - OPUS4-20991 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scholz, G. A1 - Krahl, Thoralf A1 - Ahrens, M. A1 - Martineau, C. A1 - Buzaré, J.Y. A1 - Jäger, Christian A1 - Kemnitz, E. T1 - 115In and 19F MAS NMR study of (NH4)3InF6 phases N2 - This study presents for the first time an NMR spectroscopic characterization of the room and high temperature phases of (NH4)3InF6 using 19F and 115In as probe nuclei. The reversible phase transition to the cubic phase at 353 K was followed by MAS NMR in situ. Static NMR experiments of the room temperature phase and MAS NMR experiments of the high temperature phase allowed the determination of the NMR parameters of both nuclei. Finally, the scalar In–F coupling, rarely observed in solid state NMR, is evidenced in both room and high temperature phases of (NH4)3InF6, and measured in the high temperature phase. KW - (NH4)3InF6 KW - 115In and 19F solid state NMR KW - XRD PY - 2011 DO - https://doi.org/10.1016/j.jfluchem.2011.01.010 SN - 0022-1139 SN - 1873-3328 VL - 132 IS - 4 SP - 244 EP - 249 PB - Elsevier CY - Amsterdam AN - OPUS4-23475 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gross, Thomas A1 - Treu, Dieter A1 - Ünveren, E. A1 - Kemnitz, G. A1 - Unger, Wolfgang T1 - Characterization of Cr(III) compounds of O, OH, F and Cl by XPS N2 - Cr2O3, CrCl3, α-CrF3, CrF3·3H20 and Cr(OH)3 were investigated by x-ray photoelectron (XPS) and x-ray excited Auger electron spectroscopy (XAES) using a latest generation XPS spectrometer. Non-conductive powders are analyzed with ultimate energy resolution. Multiplet splitting features and/or satellite emission were observed in the Cr 2p and Cr 3s spectra. Cr(III) compounds are of interest in many applications as for example in corrosion and catalysis. Chromia and chromium-III-fluoride activated by reaction with fluoroalkanes are very promising industrial catalysts. It is the aim of this selection of spectral reference data to enable deeper insight in the formation of catalytically active fluorinated chromia phases by using XPS analysis. KW - Chromium(III) compound KW - Cr2O3 KW - CrCl3 KW - Cr(OH)3 KW - CrF3 KW - CrF3.3H2O KW - XPS KW - XAES KW - Multiplet splitting KW - Satellite KW - Powder chromium(III) compounds PY - 2008 DO - https://doi.org/10.1116/11.20080801 SN - 1055-5269 SN - 1520-8575 VL - 15 SP - 77 EP - 123 PB - AIP CY - Woodbury, NY AN - OPUS4-23387 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - König, R. A1 - Scholz, G. A1 - Pawlik, Alf A1 - Jäger, Christian A1 - van Rossumm, B. A1 - Oschkinat, H. A1 - Kemnitz, E. T1 - Crystalline Aluminium Hydroxy Fluorides: Structural Insights Obtained by High Field Solid State NMR and Trend Analyses N2 - A series of crystalline aluminum hydroxy fluorides in cubic pyrochlore structure AlFx(OH)3-x·H2O with variable F-content x were investigated by solid-state NMR by applying different magnetic fields up to 21.1 T. Distinguishable octahedral species AlFx(OH)6-x (x = 1-6) were identified in the crystalline aluminum hydroxy fluorides. The subsequent analysis of the highfield 27Al MAS NMR data allows the derivation of the trend analysis graphs giving correlations between the 27Al chemical shifts and the quadrupolar frequencies and the F-content x in AlFx(OH)6-x. Clear trends were obtained for both, which are, along with the 19F MAS chemical-shift trend analysis presented earlier, valuable tools for the interpretation of MAS NMR spectra of amorphous AlFx(OX)3-x compounds (X = H, alkyl). Following the dehydration of the pyrochlores by solid-state NMR eventually reveals a remarkable influence of the incorporated solvent molecules (H2O) on the 19F chemical shift. On that basis, a new chemical-shift trend analysis for 19F chemical shifts in correlation with x in AlFx(OH)6-x units for proton-poor substances (in the Al, F, O, H system) was determined. By using this correlation, high-surface AlF3 has a mean bulk Al:F ratio similar to that found for ACF, namely, AlF2.8(O/OH)0.2. KW - Aluminium-27 KW - Crystalline aluminium hydroxy fluorides KW - Chemical shift trend analysis KW - High field solid state NMR KW - Quadrupolar nuclei PY - 2008 DO - https://doi.org/10.1021/jp804662f SN - 1932-7447 SN - 1089-5639 VL - 112 IS - 40 SP - 15708 EP - 15720 PB - Soc. CY - Washington, DC AN - OPUS4-18365 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - König, R. A1 - Scholz, G. A1 - Pawlik, Alf A1 - Jäger, Christian A1 - Rossum, B. van A1 - Kemnitz, E. T1 - Identification of AIFx(OR)y species in strongly disordered aluminium isopropoxide fluoride solids: a field-dependent MAS NMR study KW - Ultra high-field MAS NMR (21.1T) KW - 27 Al MAS solid state NMR KW - Fluoride xerogels KW - Sol-gel process KW - Fluorolysis KW - Quadrupolar nuclei PY - 2009 DO - https://doi.org/10.1021/jp9066795 SN - 1932-7447 SN - 1089-5639 VL - 113 IS - 35 SP - 15576 EP - 15585 PB - Soc. CY - Washington, DC AN - OPUS4-20461 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pawlik, Alf A1 - König, R. A1 - Scholz, G. A1 - Kemnitz, E. A1 - Brunklaus, G. A1 - Bertmer, M. A1 - Jäger, Christian T1 - Access to local structures of HS-AIF3 and its precursor determined by high-resolution solid-state NMR KW - Aluminium fluoride KW - 27Al NMR KW - MQMAS KW - Amorphous materials KW - Catalysts PY - 2009 DO - https://doi.org/10.1021/jp904626k SN - 1932-7447 SN - 1089-5639 VL - 113 IS - 38 SP - 16674 EP - 16680 PB - Soc. CY - Washington, DC AN - OPUS4-20463 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Feist, M. A1 - Troyanov, S.I. A1 - Mehner, Hartmut A1 - Witke, Klaus A1 - Kemnitz, E. T1 - Zwei Oxidationsstufen und vier verschiedene Koordinationen von Eisen in einer Verbindung. Synthese, Kristallstruktur und spektroskopische Charakterisierung von 1,4-Dimethylpiperazinium-Chloroferrat(II, III), (dmpipzH2)6[FeIICl4]2[FeIIICl4]2[FeIICl5] [FeIIICl6] KW - 1,4-Dimethylpiperazinium chloroferrate(II,III) KW - Crystal Structure KW - Trigonal-bipyramidal pentachloroferrate(II) KW - Mössbauer, Raman spectroscopy PY - 1999 SN - 0044-2313 SN - 1521-3749 SN - 0372-7874 SN - 0863-1786 SN - 0863-1778 IS - 625 SP - 141 EP - 146 PB - Wiley-VCH CY - Weinheim AN - OPUS4-2305 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ünveren, Ercan A1 - Kemnitz, E. A1 - Hutton, S. A1 - Lippitz, Andreas A1 - Unger, Wolfgang T1 - Analysis of highly resolved x-ray photoelectron Cr 2p spectra obtained with a Cr2O3 powder sample prepared with adhesive tape KW - High-resolution XPS KW - Cr2O3 powder KW - Multiplet splitting PY - 2004 SN - 0142-2421 SN - 1096-9918 VL - 36 SP - 92 EP - 95 PB - Wiley CY - Chichester AN - OPUS4-3427 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ünveren, Ercan A1 - Kemnitz, E. A1 - Oran, Umut A1 - Unger, Wolfgang T1 - Static TOF-SIMS Surface Analysis of a CCl2F2 Activated Chromia Catalyst Used for a Cl/F Exchange Reaction N2 - Static TOF-SIMS results strongly underpin earlier conclusions from ESCA, XANES, and tracer studies that the accumulation of fluorine and chlorine at the surface of chromia by a heterogeneous reaction with a chlorofluorocarbon compound results in the formation of mixed chromium oxide halide species and not in the nucleation of CrCl3 and/or CrF3 phases. KW - Oberflächenanalytik KW - Katalyse PY - 2004 DO - https://doi.org/10.1021/jp046773h SN - 1520-6106 SN - 1520-5207 SN - 1089-5647 VL - 108 SP - 15454 EP - 15456 PB - Soc. CY - Washington, DC AN - OPUS4-4718 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -