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 - Barheine, Sabrina A1 - Hayakawa, S. A1 - Osaka, A. A1 - Jäger, Christian T1 - Surface, interface, and bulk structure of borate containing apatitic biomaterials N2 - Nuclear magnetic resonance (NMR) has been used for a detailed investigation of the borate incorporation in apatitic biomaterials prepared by high-temperature solid-state reaction sintering. The NMR data clearly show that crystalline hydroxyapatite (HAp) does exist, but it contains only about 30% of the entire phosphate content of the sample. The main phosphate content of about 70% forms a disordered calcium phosphate phase (BCaP) that accommodates the borate units in two structurally different trigonal BO33- groups besides some minor linear BO2- units. The average chemical composition of BCaP was estimated from the NMR spectra. Furthermore, a structural model of these particles is proposed, where HAp forms the crystalline core of these crystals covered by the disordered BCaP, suggesting that the BCaP phase is responsible for the adhesion properties of organic molecules like proteins and not HAp that is the only significant crystalline phase (XRD). Furthermore, the presence of an interface between HAp and BCaP is discussed based on various NMR experiments, including a triple-resonant 11B-31P cross-polarization edited 31P NMR spectrum with subsequent 31P{1H} REDOR (Rotational Echo DOuble Resonance) dephasing. PY - 2009 DO - https://doi.org/10.1021/cm900204q SN - 0897-4756 SN - 1520-5002 VL - 21 IS - 14 SP - 3102 EP - 3109 PB - American Chemical Society CY - Washington, DC AN - OPUS4-19723 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - Thermal Decomposition of Flame-Retarded Polycarbonat / Silicon Rubber Blends: A Solid-State NMR Investigation T2 - Festkörper-NMR-Methoden und Anwendungen in der Materialforschung, Seminar der Universität Tübingen CY - Bad Hindelang, Germany DA - 2010-07-18 PY - 2010 AN - OPUS4-21679 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - Thermal Decomposition of Flame-Retarded Polycarbonat / Silicon Rubber Blends: A Solid-State NMR Investigation T2 - 52. Rocky Mountain Conference on Analytical Chemistry CY - Snowmass, CO, USA DA - 2010-08-01 PY - 2010 AN - OPUS4-21680 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - 31P MAS NMR - a Method for Analysis ans Development of Complex Bioceramics based on Ca 10(K,Na)(PO 4)7 T2 - 52nd Anual Rocky Mountain Conference on Analytical Chemistry CY - Snowmass, CO, USA DA - 2010-08-01 PY - 2010 AN - OPUS4-21702 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Barheine, Sabrina A1 - Jäger, Christian T1 - A NMR investigation of borate incorpation in apatitic biomaterials T2 - Gesellschaft Deutscher Chemiker CY - Regensburg, Germany DA - 2008-09-22 PY - 2008 AN - OPUS4-17966 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Koudelka, L. A1 - Mosner, P. A1 - Zeyer-Düsterer, Michaela A1 - Jäger, Christian ED - Brooks, H. T1 - Study of potassium-zinc borophosphate glasses N2 - Potassium–zinc borophosphate glasses were prepared and studied in two compositional series xK2O–(50–x)ZnO–10B2O3–40P2O5 and xK2O–(50–x)ZnO–20B2O3–30P2O5 with x = 0, 10, 20, 30, 40 and 50 mol% K2O. The replacement of zinc by potassium decreases the density and increases the molar volume of these glasses, whereas glass transition temperature and chemical durability decrease with increasing potassium content. Structural changes were studied by 11B and 31P MAS NMR and Raman spectroscopy. The observed changes in the spectra and the properties of the studied glasses can be ascribed to several reasons and namely to the differences in the space occupied by cations Zn2+ and 2K+, the differences in the electronegativity of zinc and potassium and a large difference in the field strength of Zn2+ and K+ cations and thus higher ionicity of K–O bonds in comparison with Zn–O bonds. KW - A. Glasses KW - C. Raman spectroscopy KW - D. Nuclear magnetic resonance PY - 2007 DO - https://doi.org/10.1016/j.jpcs.2007.02.012 SN - 0022-3697 VL - 68 IS - 4 SP - 638 EP - 644 PB - Pergamon Press CY - New York, NY AN - OPUS4-17579 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maltsev, Sergey A1 - Duer, M.J. A1 - Murray, R.C. A1 - Jäger, Christian T1 - A solid-state NMR comparison of the mineral structure in bone from diseases joints in the horse N2 - In this work, subchondral cortical bone material is investigated from the joints of five horses, three of which presented with no clinical signs or radiographic signs of osteoarthritis and two of which suffered osteoarthritis joint disease, as judged by clinical and radiographic assessment and histological findings. The horse is a good model for osteoarthritis in humans, so the aim of this study is to use nuclear magnetic resonance (NMR) for a detailed investigation of the bone structure in bone material affected by osteoarthritis. In particular, we report on the assessment of the mineral structure of these samples as viewed by solid-state NMR. KW - Bone KW - Osteoarthritis KW - NMR PY - 2007 DO - https://doi.org/10.1007/s10853-007-1916-z SN - 0022-2461 SN - 1573-4803 VL - 42 IS - 21 SP - 8804 EP - 8810 PB - Springer Science + Business Media B.V. CY - Norwell, Mass. AN - OPUS4-17580 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Fichera, M.A. A1 - Jäger, Christian A1 - Schartel, Bernhard A1 - Braun, Ulrike A1 - Pawlowski, Kristin ED - Menachem Lewin, T1 - Solid-state NMR for monitoring the thermal decomposition of flame retarded polymers PY - 2007 SN - 1-59623-321-4 VL - I SP - 9 EP - 19 PB - BCC Research CY - Norwalk, CT, USA AN - OPUS4-17581 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jäger, Christian A1 - Cölfen, H. T1 - Fine structure of nacre revealed by solid state 13C and 1H NMR N2 - Solid-state NMR investigations of nacre reveal the presence of an amorphous surface layer around the aragonite platelets. This surface layer contains hydrogen carbonate groups, presumably at its outer surface and water molecules slightly hindered in their mobility in a proton ratio of 1:33, i.e. about 16 water molecules per HCO3– unit. The 1H spin–lattice relaxation T1 times of protons in the protein/polysaccharide matrix (about 300 ms), of the mobile water molecules (2 s) and of the hydrogen carbonate units (12 s) differ significantly, thus revealing no spatial proximity between the protein/polysaccharide matrix with the hydrogen carbonate units of the amorphous carbonate surface layer suggesting no significant interaction between protein matrix and the amorphous calcium carbonate (ACC) layer. These results are discussed in the context of recent publications on novel structural aspects of nacre. KW - NMR KW - Nacre KW - Amorphous carbonate layer KW - Protein interaction PY - 2007 DO - https://doi.org/10.1039/b708600h SN - 1466-8033 VL - 9 SP - 1237 EP - 1244 CY - London, UK AN - OPUS4-17582 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wise, Erica R. A1 - Maltsev, Sergey A1 - Davies, M.E. A1 - Duer, M.J. A1 - Jäger, Christian A1 - Loveridge, N. A1 - Murray, Rachel C. A1 - Reid, D.G. T1 - The Organic - Mineral Interface in Bone Is Predominantly Polysaccharide KW - NMR KW - Bone KW - Mineral-organic interface PY - 2007 DO - https://doi.org/10.1021/cm702054c SN - 0897-4756 SN - 1520-5002 VL - 19 IS - 21 SP - 5055 EP - 5057 PB - American Chemical Society CY - Washington, DC AN - OPUS4-17583 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hayakawa, S. A1 - Sakai, A. A1 - Tsuru, K. A1 - Osaka, A. A1 - Fujii, E. A1 - Kawabata, K. A1 - Jäger, Christian T1 - Preparation and Characterization of Boron-containing Hydroxyapatite N2 - Boron-containing hydroxyapatite (BHAp) particles were synthesized by the wet chemical processing method and subsequent thermal treatment at the temperature ranging from 700-1200°C, and examined the effect of boron introduction on the microstructure of BHAp. The local structure around boron and phosphorus in the BHAp was analyzed by solid-state magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy. The heat-treatment above 700°C induced the thermal decomposition of HAp to β-TCP and then the chemical reaction between HAp and B(OH)3 was induced above 900°C, resulting in the formation of boron-substituted HAp particles accompanied by the formation of β-TCP and its transformation to α-TCP above 1200°C. KW - Hydroxyapatite KW - Boron KW - Structure KW - NMR KW - Thermal treatment PY - 2008 SN - 1013-9826 VL - 361-363 SP - 191 EP - 194 PB - Trans Tech Publ. CY - Aedermannsdorf AN - OPUS4-17584 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Karrasch, Andrea A1 - Jäger, Christian A1 - Karakawa, M. A1 - Nakatsubo, F. A1 - Potthast, A. A1 - Rosenau, T. T1 - Solid-state NMR studies of methyl celluloses. Part 1: regioselectively substituted celluloses as standards for establishing an NMR data basis N2 - Three methyl celluloses with completely uniform substitution pattern, 2-O-methyl cellulose (1), 3-O-methyl cellulose (2) and 6-O-methyl cellulose (3), were prepared according to the cationic ring opening polymerization approaches starting from substituted 1,2,4-orthopivalate derivatives of D-glucose. These samples allowed for the first time to sort out the methyl substitution effects on solid-state NMR chemical shifts and relaxation. Dipolar dephasing experiments allowed the detection and assignment (1H, 13C) of the methyl groups. In 1 and 2, these resonances overlapped with those of C-6, whereas in 3, the methyl signal experienced a low-field shift into the region of C-2,3,5. 13C T1 experiments were used to verify different relaxation behavior of the carbon sites, particularly the short relaxation time of at the carbon substitution site next to the methyl groups. This effect was used to unambiguously identify the 13C chemical shifts of the carbons carrying the methoxyl substituent, although they overlap with all resonances in the C-2,3,5 region. The data obtained for the standard samples with uniform substitution will now be used as the basis for determining methylation patterns and substitution degree in commercial methyl celluloses. KW - Methyl cellulose KW - Solid-state NMR KW - CPMAS NMR KW - Substituent distribution KW - Substitution pattern KW - Cationic ring opening polymerization KW - Methylation PY - 2009 DO - https://doi.org/10.1007/s10570-008-9247-z SN - 0969-0239 SN - 1572-882X VL - 16 SP - 129 EP - 137 PB - Chapman & Hall CY - London AN - OPUS4-18913 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Barheine, Sabrina A1 - Hayakawa, S. A1 - Osaka, A. A1 - Jäger, Christian T1 - A NMR investigation of borate incorporation in apatitic biomaterials N2 - The incorporation of ions in the lattice of hydroxyapatite alters significantly its structure. Particularly, if anions such as trigonal borate units are accommodated in the lattice severe distortions must occur around the substitution site because of different geometric shape, electric charge and anion size. Solid-state NMR has been used to investigate this problem in detail for a hydroxyapatite sample synthesized by high temperature solid state reaction. The results clearly verify the existence of network distortions. Indeed, only about 1/3 of the total phosphate content forms crystalline hydroxyapatite (also found in XRD) whereas the residual amount is contained in two different phosphate sites with 31P chemical shifts of 5.5 ppm and 2.3 ppm, but broad resonances lines suggesting disorder. Furthermore, a novel proton signal at -0.6 ppm was found which is directly associated with the borate incorporation. No specific correlation of the two structurally different borate units with the two phosphate groups is found. KW - Apatite KW - Borate KW - Biomaterials KW - Solid-state NMR PY - 2009 UR - http://www.scientific.net/0-87849-353-0/205/ DO - https://doi.org/10.4028/3-908453-07-0.205 SN - 1013-9826 VL - 396-398 SP - 205 EP - 208 PB - Trans Tech Publ. CY - Aedermannsdorf AN - OPUS4-18914 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yoneda, Y. A1 - Mereiter, K. A1 - Jäger, Christian A1 - Brecker, L. A1 - Kosma, P. A1 - Rosenau, T. A1 - French, A. T1 - Van der Waals versus Hydrogen-Bonding Forces in a Crystalline Analog of Cellotetraose: Cyclohexyl 4'-O-Cyclohexyl Beta-D-Cellobioside Cyclohexane Solvate KW - Cellobioside KW - Cellotetraose KW - Cellulose KW - Solid state NMR PY - 2008 DO - https://doi.org/10.1021/ja805147t SN - 0002-7863 SN - 1520-5126 VL - 130 SP - 16678 EP - 16690 PB - American Chemical Society CY - Washington, DC AN - OPUS4-18915 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - NMR beyond limits: Surfaces of phosphate nanoparticles and interface in biomaterials T2 - Universität Mainz CY - Mainz, Germany DA - 2007-12-17 PY - 2007 AN - OPUS4-19189 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Karrasch, Andrea A1 - Jäger, Christian A1 - Saake, B. A1 - Potthast, A. A1 - Rosenau, T. T1 - Solid-state NMR studies of methyl celluloses. Part 2: Determination of degree of substitution and O-6 vs. O-2/O-3 substituent distribution in commercial methyl cellulose samples N2 - Solid state NMR spectroscopy was applied to determine the overall degree of substitution (DS) and the degrees of substitution at C-6 (DSC-6) and C-2/3 (DSC-2/3). Four commercial methyl cellulose samples were used, having a DS between 0.51 and 1.96 as determined by wet-chemical analysis. The strategy and optimization of the NMR data acquisition as well as the data evaluation procedures are explained in detail. Optimization of the approach mainly comprised (a) maximizing the signal by choice of NMR probe, MAS spinning frequency and B0 field, (b) minimizing the measurement time by a Torchia-type experiment and (c) suppressing probe background by rotor-synchronized echo detection. Data evaluation used simply the integration of three different spectral ranges in the 13C NMR spectrum. The results of the experiments were in good agreement with the wet-chemical data. The NMR approach takes about the same analysis time as the conventional hydrolysis/chromatography analysis. However, it is a generally applicable and simple alternative without need for an extended sample preparation which is most useful if wet-chemical/chromatographic analyses are undesired or unavailable. Further studies have to concentrate on the validation of the analytical method and application to a larger sample array. KW - Methyl cellulose KW - Solid-state NMR KW - 13C CPMAS NMR KW - Rotor-synchronized echo sequence KW - Substituent distribution KW - Substitution pattern KW - Degree of substitution PY - 2009 DO - https://doi.org/10.1007/s10570-009-9304-2 SN - 0969-0239 SN - 1572-882X VL - 16 IS - 6 SP - 1159 EP - 1166 PB - Chapman & Hall CY - London AN - OPUS4-21130 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lutz, W. A1 - Kurzhals, R. A1 - Sauerbeck, S. A1 - Toufar, H. A1 - Buhl, J.-C. A1 - Gesing, T. A1 - Altenburg, Wolfgang A1 - Jäger, Christian T1 - Hydrothermal stability of zeolite SAPO-11 N2 - The hydrothermal stability of SAPO-11 was studied in water of autogenous pressure as function of the temperature. SAPO-11 remained crystalline up to 190 °C. Thereby, it was observed, parent as well as hydrothermally treated samples showed similarities to the isotypic structure of zeolite AlPO-11 called here AELdry. After fully hydration of the samples, AELdry changed completely into a hydrated AELwet structure of another framework symmetry. The transition from calcined to hydrated state was reversible for both the parent and the hydrothermally treated samples. 27Al and 31P NMR MAS spectra showed a single resonance typical for AlPO4 type tetrahedra for the calcined parent and hydrothermally treated samples. Upon hydration, the single AlPO4 resonance signal split into three different signals as is the case for the corresponding 31P signals. By means of NH3-TPD measurement a loss of acidity was detected after the hydrothermal treatment as follows from a framework desilication. Nitrogen and water adsorption decreased systematically. At 210 °C a non-zeolitic, non-porous phase was irreversibly formed. The XRD pattern of this phase shows resemblance to a synthetic aluminium phosphate of the tridymite structure type. KW - Zeolite KW - Silicoaluminophosphate KW - SAPO-11 KW - Hydrothermal stability KW - Phase transformation PY - 2010 DO - https://doi.org/10.1016/j.micromeso.2009.08.003 SN - 1387-1811 SN - 1873-3093 VL - 132 IS - 1-2 SP - 31 EP - 36 PB - Elsevier CY - Amsterdam AN - OPUS4-21131 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Debatin, F. A1 - Thomas, A. A1 - Kelling, A. A1 - Hedin, N. A1 - Bacsik, Z. A1 - Senkovska, I. A1 - Kaskel, S. A1 - Junginger, M. A1 - Müller, H. A1 - Schilde, U. A1 - Jäger, Christian A1 - Friedrich, A. A1 - Holdt, H.-J. T1 - In situ synthesis of an imidazolate-4-amide-5-imidate ligand and formation of a microporous zinc-organic framework with H2-and CO2-storage ability KW - Metal-organic framework KW - Synthesis KW - XRD KW - FTIR KW - NMR KW - Gas sorption KW - Microporous materials KW - N,O ligands KW - Solvothermal synthesis PY - 2010 DO - https://doi.org/10.1002/anie.200906188 SN - 1433-7851 SN - 1521-3773 SN - 0570-0833 VL - 49 IS - 7 SP - 1258 EP - 1262 PB - Wiley-VCH CY - Weinheim AN - OPUS4-21132 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 - Dreßler, Martin A1 - Nofz, Marianne A1 - Pauli, Jutta A1 - Jäger, Christian T1 - Influence of polyvinylpyrrolidone (PVP) on alumina sols prepared by a modified Yoldas procedure N2 - Al13 polycations containing alumina sols, prepared by a modified Yoldas procedure were mixed with polyvinylpyrrolidone (PVP). Although Al speciation in freshly prepared sols was not affected by PVP addition the decay rate of Al13 polycations was slightly decreased in PVP-containing sols. PVP does not show any influence on particle size and particle growth. The influence of PVP addition on viscosity and flow behavior of modified Yoldas sols depends on their solids content and NO3-/Al molar ratio. KW - ModifiedYoldas sols KW - PVP KW - NMR KW - Rheology KW - Particle size KW - Aging PY - 2008 DO - https://doi.org/10.1007/s10971-008-1798-9 SN - 0928-0707 SN - 1573-4846 VL - 47 IS - 3 SP - 260 EP - 267 PB - Kluwer Academic Publ. CY - Dordrecht AN - OPUS4-17854 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Karrasch, Andrea A1 - Jäger, Christian T1 - Thermal decomposition of PDMS in flame-retarded bisphenol-A polycarbonate: A solid-state NMR investigation T2 - GDCh-Tagung Magnetische Resonanz 2008 CY - Regensburg, Germany DA - 2008-09-22 PY - 2008 AN - OPUS4-17831 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - Bulk and surfaces of nanosized calcium phosphates and their interaction with organic molecules in bone and synthetic biomaterials T2 - The 6th International Symposium on Inorganic Phosphate Materials (ISIPM-6- La Rochelle 2008) CY - La Rochelle, France DA - 2008-08-24 PY - 2008 AN - OPUS4-17883 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian A1 - Barheine, Sabrina T1 - A NMR investigation of borate incorpation in apatitic biomaterials T2 - 21st International Symposium of Ceramics in Medicine - Bioceramics 21 CY - Búzios, Brazil DA - 2008-10-21 PY - 2008 AN - OPUS4-17884 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - Mission Impossible? Surfaces of phosphate nanoparticles and the mineral-organic interface in biomaterials T2 - Max-Planck-Institut für Chemische Physik Fester Stoffe CY - Dresden, Germany DA - 2008-05-09 PY - 2008 AN - OPUS4-17885 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - Mission Impossible? Surfaces of phosphate nanoparticles and the mineral-organic interface in biomaterials T2 - Seminar "Festkörper-NMR-Methoden und Anwendungen in der Materialforschung", Universität Tübingen CY - Bad Hindelang, Germany DA - 2008-07-13 PY - 2008 AN - OPUS4-17886 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Aguiar, H. A1 - Solla, E.L. A1 - Serra, J. A1 - González, P. A1 - León, B. A1 - Malz, Frank A1 - Jäger, Christian T1 - Raman and NMR study of bioactive Na2O-MgO-CaO-P2O5-SiO2 glasses N2 - The results of a structural study combining NMR and Raman spectroscopy of several melt-derived glasses in the system Na2O–MgO–CaO–P2O5–SiO2 are presented. The Raman spectra show clear changes in the Si–O–Si vibrational modes (related to the bridging oxygen atoms, BO) and also verify the presence of non-bridging oxygen atoms (NBO), also named terminal oxygens. The intensity of the Si–O–NBO stretching mode depends on the cation concentration. It can be concluded from the NMR studies that the MgO-containing samples have orthophosphate units charge-compensated by Ca2+ and Mg2+. The silicate matrix also contains both types of two-valent cations and consists of Q2 and Q1 units. Similarly, the Na2O-containing samples contain isolated orthophosphate units in a silicate matrix (Q2 and Q3 units), both charge-compensated by mixed cations Ca2+ and Na+. These experimental data were compared with theoretical parameters given by the Stevels model, which is a suitable tool for understanding bioactive behavior of these glasses. Furthermore, results of the in vitro tests carried out in simulated body fluids are presented and compared with both Raman and NMR structural data. KW - Raman KW - NMR KW - Solid state KW - Bioactive glasses KW - Glass ceramics PY - 2008 DO - https://doi.org/10.1016/j.jnoncrysol.2008.07.033 SN - 0022-3093 VL - 354 IS - 45-46 SP - 5004 EP - 5008 PB - North-Holland Publ. Co. CY - Amsterdam AN - OPUS4-18364 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 - Schmidt, T. A1 - Dai, Z. A1 - Drexler, H.-J. A1 - Baumann, W. A1 - Jäger, Christian A1 - Pfeifer, Dietmar A1 - Heller, D. T1 - Novel contributions to the mechanism of the enantioselective hydrogenation of dimethyl itaconate with rhodium complexes KW - Enantioselective Hydrogenation KW - Rhodium-Phosphor-Complex KW - Powder Diffractometry KW - Hr- and Solid State NMR-Spectroscpy KW - Asymmetric catalysis KW - Hydrogenation KW - Kinetics KW - Reaction mechanisms KW - Rhodium PY - 2008 DO - https://doi.org/10.1002/chem.200800389 SN - 0947-6539 SN - 1521-3765 VL - 14 IS - 15 SP - 4469 EP - 4471 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-18368 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maltsev, Sergey A1 - Jäger, Christian T1 - Solid-state NMR spectroscopy using the lost I spin magnetization in polarization transfer experiments N2 - A variation of the cross polarization (CP) experiment is discussed. The method requires two scans where the difference signal is equivalent to the I spin magnetization that is transferred to the S spins. The acquired signal is equivalent to F1 sum projection of a two-dimensional (2D) heteronuclear correlation experiment and is obtained by just two scans without the need to increment the indirect time domain t1. Any polarization transfer method and any kind of spin manipulations during the t1 incrementation period of a 2D NMR experiment can be applied. The method allows fast measurements of the CP transfer, particularly if various S spins signal overlap and is good for spectral editing of I spin signals with contact to S spins. Various examples for biomaterials are presented. Most importantly, this novel approach is ideal for detailed investigations of organic–mineral interfaces in bone, here demonstrated for O-phospho-L-serine as simple model compound. KW - NMR KW - Double resonance KW - Cross polarization KW - Heteronuclear correlation KW - Biomaterials KW - Hydroxyapaptite KW - Bone PY - 2008 DO - https://doi.org/10.1016/j.ssnmr.2008.08.001 SN - 0926-2040 SN - 1527-3326 VL - 34 IS - 3 SP - 175 EP - 179 PB - Academ. Press CY - Orlando, Fla. AN - OPUS4-18377 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pawlik, Alf A1 - Jäger, Christian T1 - Catalytically active High-Surface Aluminiumfluoride and its Precursor a Solid-State NMR Study. T2 - 6th Alpine Conference on Solid-State NMR CY - Chamonix, France DA - 2009-09-13 PY - 2009 AN - OPUS4-19374 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krahl, Thoralf A1 - Jäger, Christian T1 - Predicting Phase Compositions of CA10(K,Na)(PO4)7 Melts by 31PMAS NMR T2 - 22nd International Symposium of Ceramics in Medicine - Bioceramics 22 CY - Daegu, South Korea DA - 2009-10-26 PY - 2009 AN - OPUS4-19416 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Barheine, Sabrina A1 - Jäger, Christian T1 - Surface, interface and bulk structure of borate containing apatitic biomaterials T2 - The Alpine Conference on Solid-State NMR CY - Chamonix, France DA - 2009-09-13 PY - 2009 AN - OPUS4-19370 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Karrasch, Andrea A1 - Jäger, Christian T1 - Solid-state NMR Studies of Methyl Celluloses T2 - The Alpine Conference on Solid-State NMR CY - Chamonix, France DA - 2009-09-13 PY - 2009 AN - OPUS4-19372 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - NMR studies of short and medium range order in glasses and disordered surfaces of biomaterials T2 - MPG Summer School on Amorphous Solids in Physics and Biology CY - Neuhardenberg, Germany DA - 2009-06-01 PY - 2009 AN - OPUS4-19481 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - Order and disorder in biominerals: News about bone and sea urchin spines. T2 - GDCh-Fachgruppenjahrestagung "Magnetische Resonanzspektroskopie" CY - Dresden, Germany DA - 2009-09-21 PY - 2009 AN - OPUS4-19526 LA - deu 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 - Bartoszek, M. A1 - Eckelt, R. A1 - Jäger, Christian A1 - Kosslick, H. A1 - Pawlik, Alf A1 - Schulz, A. T1 - Mesoporous silica-aluminas derived from precipitation: a study of the acidity, textural properties and catalytic performance KW - Silica-alumina KW - Solid state NMR KW - Acidity KW - Silicates KW - Tetrahedral aluminium PY - 2009 DO - https://doi.org/10.1007/s10853-009-3580-y SN - 0022-2461 SN - 1573-4803 VL - 44 IS - 24 SP - 6629 EP - 6636 PB - Springer Science + Business Media B.V. CY - Norwell, Mass. AN - OPUS4-20462 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 - CONF A1 - Krahl, Thoralf A1 - Gildenhaar, Renate A1 - Kenning, Hilke A1 - Berger, Georg A1 - Jäger, Christian ED - Kim, Sukyoung T1 - Predicting phase compositions of samples in the ternary system Ca2KNa(PO4)2-Ca3(PO4)2-Ca2P2O7 using 31P MAS NMR T2 - 22nd International symposium on ceramics in medicine (Bioceramics 22) CY - Daegu, Korea DA - 2009-10-26 KW - NMR KW - Bone substitute materials KW - Alkali calcium phosphates KW - TCP KW - Ca10(K,NA)(PO4)7 PY - 2009 SP - 11 EP - 14 AN - OPUS4-20656 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pawlowski, Kristin A1 - Schartel, Bernhard A1 - Fichera, Mario Augusto A1 - Jäger, Christian T1 - Flame retardancy mechanisms of bisphenol A bis(diphenyl phosphate) in combination with zinc borate in bisphenol A polycarbonate/Acrylonitrile-butadiene-styrene blends N2 - Bisphenol A polycarbonate/acrylonitrile–butadiene–styrene (PC/ABS) with and without bisphenol A bis(diphenyl phosphate) (BDP) and 5 wt.% zinc borate (Znb) were investigated. The pyrolysis was studied by thermogravimetry (TG), TG-FTIR and NMR, the fire behaviour with a cone calorimeter applying different heat fluxes, LOI and UL 94. Fire residues were examined with NMR. BDP affects the decomposition of PC/ABS and acts as a flame retardant in the gas and condensed phases. The addition of Znb results in an additional hydrolysis of PC. The fire behaviour is similar to PC/ABS, aside from a slightly increased LOI and a reduced peak heat release rate, both caused by borates improving the barrier properties of the char. In PC/ABS + BDP + Znb, the addition of Znb yields a borate network and amorphous phosphates. Znb also reacts with BDP to form alpha-zinc phosphate and borophosphates that suppress the original flame retardancy mechanisms of BDP. The inorganic–organic residue formed provides more effective flame retardancy, in particular at low irradiation in the cone calorimeter, and a clear synergy in LOI, whereas for more developed fires BDP + Znb become less effective than BDP in PC/ABS with respect to the total heat evolved. KW - Flame retardancy KW - PC/ABS KW - Aryl phosphate KW - Zinc borate KW - Flammability PY - 2010 DO - https://doi.org/10.1016/j.tca.2009.10.007 SN - 0040-6031 SN - 1872-762X VL - 498 IS - 1-2 SP - 92 EP - 99 PB - Elsevier CY - Amsterdam AN - OPUS4-20746 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Pikacz, E. A1 - Seefeldt, Henrik A1 - Schartel, Bernhard A1 - Braun, Ulrike A1 - Karrasch, Andrea A1 - Jäger, Christian T1 - Flame retardancy in PC/Silicone rubber blends using BDP and additional additives T2 - 20th Annual conference on recent advances in flame retardancy of polymeric materials CY - Stamford, CT, USA DA - 2009-06-01 KW - Flame retardancy KW - PC blend KW - Aryl phosphate PY - 2009 SN - 1-59623-509-8 VL - 20 IS - Chapter IV-B SP - 236 EP - 246 CY - Wellesley, MA, USA AN - OPUS4-20703 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan A1 - Dreßler, Martin A1 - Nofz, Marianne A1 - Pauli, Jutta A1 - Jäger, Christian A1 - Scholz, G. ED - Krämer, V. T1 - Phasentransformationen von anorganisch modifizierten Alumo-Xerogelen T2 - Jahrestagung der Gesellschaft für Thermische Analyse e.V. CY - Augsburg, Deutschland DA - 2003-09-15 PY - 2003 SP - 1 EP - 2 AN - OPUS4-2668 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - About nanocrystalline Hydroxyapatite and the binding of apatite in bone: a novel NMR perspective T2 - Vortrag am Max-Planck-Institut für Kolloid- und Grenzflächenforschung, Abteilung Biomaterialien CY - Potsdam, Germany DA - 2004-07-14 PY - 2004 AN - OPUS4-4636 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - About Nanocrystalline Hydroxyapatite and the Binding of Apatite in Bone: A Solid State-NMR Perspective T2 - 7th International Essen Symposium on Biomaterials and Biomechanics: Fundamentals and Clinical Applications CY - Essen, Germany DA - 2004-10-06 PY - 2004 AN - OPUS4-5501 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - Nanocrystalline Hydroxyapatite and Apatite Binding in Bone: A Solid State-NMR Perspective T2 - EENC/Congress Ampere CY - Lille, France DA - 2004-08-06 PY - 2004 AN - OPUS4-5502 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - NMR studies of the structure of precipitated calcium phosphates and carbonates and of mineral protein interactions T2 - DFG-Antragskolloquium des Schwerpunktprogramms "Biomineralisation" CY - Bonn, Germany DA - 2005-02-21 PY - 2005 AN - OPUS4-7269 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - NMR studies of the structure of precipitated calcium phosphates and carbonates and of mineral protein interactions T2 - DFG-Antragskolloquium des Schwerpunktprogramms "Biomineralisation" CY - Bonn, Germany DA - 2005-02-21 PY - 2005 AN - OPUS4-7270 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - Übersichtsposter über Expertise und Angebot der AG "NMR-Spektroskopie" zur Leitinitiative "NanoforLife" T2 - Auftaktveranstaltung zur Leitinnovation "NanoforLife" CY - Düsseldorf, Germany DA - 2005-01-26 PY - 2005 AN - OPUS4-7271 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - NMR characterization of nanocrystalline hydroxyapatite and of the mineral-protein interface in bone T2 - 46th ENC CY - Providence, RI, USA DA - 2005-04-11 PY - 2005 AN - OPUS4-7373 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - NMR characterization of nanocrystalline hydroxyapatite and of the mineral-protein interface in bone T2 - Workshop "Biomineralization"; University of Cambridge CY - Cambridge, England DA - 2005-04-18 PY - 2005 AN - OPUS4-7374 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - Investigation of the Structure of Phosphate-Based Glasses using 170 NMR T2 - DFG-Berichtskolloquium 750MHz-Widebore-Spektrometer Leipzig CY - Leipzig, Germany DA - 2005-05-25 PY - 2005 AN - OPUS4-7549 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian A1 - Duer, M. J. T1 - Solid-state NMR: a tool for probing the protein-mineral interface and other structures in bone T2 - EUROMAR 2005/EENC 2005 CY - Veldhoven, Netherlands DA - 2005-07-03 PY - 2005 AN - OPUS4-7551 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - -NMR characterization of nanocrystalline hydroxyapatite and of the mineral-protein in bone T2 - Worshop "Biomineralization", Univ. Cambridge CY - Cambridge, England DA - 2005-04-18 PY - 2005 AN - OPUS4-7552 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - NMR characterization of nanocrystalline hydroxyapatite and of the mineral-protein interface in bone T2 - 46th ENC CY - Providence, RI, USA DA - 2005-04-11 PY - 2005 AN - OPUS4-7553 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - NMR characterization of nanocrystalline hydroxyapatite and of the mineral-protein interface in bone T2 - Tag der Chemie CY - Berlin, Germany DA - 2005-06-08 PY - 2005 AN - OPUS4-7555 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - Complete Ring Assignment of Crystalline and Amorphous Cellulose Ia T2 - Symposium "New Developments in High Field NMR" CY - Leipzig, Germany DA - 2002-04-25 PY - 2002 AN - OPUS4-10871 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - NMR-Unrtersuchungen zur Struktur nanoskaliger Biomaterialien: Phosphate und Carbonate T2 - DFG-Rundtischgespräch "Magnetische Spektroskopie der Struktur und Dynamik nano- und mesoskopischer Systeme" CY - Hirschegg, Austria DA - 2005-09-04 PY - 2005 AN - OPUS4-10881 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - A solid state NMR study of the biomineral nacre T2 - GDCh-Fachgruppen-Jahrestagung "Magnetische Resonanzspektroskopie" CY - Mainz, Germany DA - 2005-09-26 PY - 2005 AN - OPUS4-10882 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - Progress of structural elucidation of amorphous calcium phosphate (ACP) and hydroxyapatite (HAp): Disorder and surfaces as seen by solid state NMR T2 - Bioceramics 18 CY - Kyoto, Japan DA - 2005-12-05 PY - 2005 AN - OPUS4-10883 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - 17O NMR of Phosphate Glasses and Ambiguities of Comparative XRD and NMR Studies of Phosphate Biomaterials T2 - American Ceramic Society, Glass & Optical Materials Division Fall Meeting CY - Corning, NY, USA DA - 2003-10-01 PY - 2003 AN - OPUS4-3755 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - Solid State NMR of Solid Bacterial Cellulose: Assignment of the Carbon Signals to the Ring Strukture T2 - Chemistry Departament, University of Cambridge CY - Cambridge, England DA - 2003-11-01 PY - 2003 AN - OPUS4-3756 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - Solid State NMR and Materials Research: Examples from Glasses to Cellulose T2 - Berlin Magnetic Resonance Seminar CY - Berlin, Germany DA - 2003-03-13 PY - 2003 AN - OPUS4-3749 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - About Nanocrystalline Hydroxyapatite and Apatite Binding in Bone: A Solid State-NMR Perspective T2 - BRSG-Conference "Recent Advances and Applications of Solid State NMR", University of Warwick CY - Warwick, England DA - 2004-08-14 PY - 2004 AN - OPUS4-4767 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - Observation of the Glycosidic Bond and Complete Ring Assignment of the 13C Signals of Bacterial Cellulose T2 - 45th Rocky Mountain Conference on Analytical Chemistry CY - Denver, CO, USA DA - 2003-07-27 PY - 2003 AN - OPUS4-4796 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - 17O NMR of Phosphate and Borophosphate Glasses T2 - 45th Rocky Mountain Conference on Analytical Chemistry CY - Denver, CO, USA DA - 2003-07-27 PY - 2003 AN - OPUS4-4797 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - Observation of the Glycosidic Bond and Complete Ring Assignment of the 13C Signals of Bacterial Celllulose T2 - 3rd Alpine Conference on Solid-State NMR CY - Chamonix, France DA - 2003-09-14 PY - 2003 AN - OPUS4-4798 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - Observation of the Glycosidic Bond and Complete Ring Assignment of the 13C Signals of Bacterial Cellulose T2 - 25. Jahrestagung der Fachgruppe "Magnetische Resonanzspektroskopie" CY - Leipzig, Germany DA - 2003-09-29 PY - 2003 AN - OPUS4-4882 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian A1 - Hartmann, P. A1 - Barth, S. A1 - Vogel, J. A1 - Pauli, Jutta A1 - Schmauder, H.-P. T1 - NMR und Biomaterialien - Was kann man über plasmagespritzte Apatitschichten und Cellulose lernen? T2 - Kolloquium des SFB 428 CY - Freiburg, Deutschland DA - 2002-12-10 PY - 2002 AN - OPUS4-2127 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Spange, S. A1 - Seifert, Alexander A1 - Müller, Hansjörg A1 - Hesse, S. A1 - Jäger, Christian T1 - Fabrication of chromophoric xerogels by senergistic combination of nucleophilic aromatic substitution and the sol-gel process N2 - The nucleophilic substitution of fluorine of aromatic compounds with n-aminoalkyl trialkoxysilanes and consecutive sol-gel process have been used for the fabrication of various chromophoric sol-gel materials. The displacement of the fluoro substituent of an activated aromatic molecule occurs by a primary or secondary amino group of (CH3O)3Si-(CH2)3-NHR [R- = H-; CH3-, (CH3O)3Si-(CH2)3-] in tetraalkoxysilane or alcohol as solvent and the sol-gel process can be carried in the same vessel. The HF formed is trapped by a tertiary amine and simultaneously serves as the catalyst for the sol-gel process. Various aromatic compounds have been checked for this purpose: 1-(4-fluorophenyl)-2-nitroethylene, 1-(4-fluorophenyl)-2,2-dicyanoethylene, 4-fluorobenzonitrile, 4-fluoronitrobenzene, 4,4prime-difluorobenzophenone, 4,4prime-difluorobenzil, 7,7prime-difluorodibenzylideneacetone, tetrafluoro-p-benzoquinone, and 1,5-difluoro-2,4-dinitrobenzene. Mono and disubstitution has been studied by UV/Vis- and solid state NMR spectroscopy of the xerogels. PY - 2003 DO - https://doi.org/10.1023/A:1020789318803 SN - 0928-0707 SN - 1573-4846 VL - 26 SP - 77 EP - 81 PB - Kluwer Academic Publ. CY - Dordrecht AN - OPUS4-2128 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Peuker, Christel A1 - Reinholz, Uwe A1 - Jäger, Christian A1 - Pauli, Jutta A1 - Geißler, Heinz T1 - Extinction coefficients of the OH bands in the IR spectra of basic and water-enriched silicate and aluminosilicate glasses PY - 2003 SN - 0927-4472 VL - 76 IS - 5 SP - 227 EP - 233 PB - Elsevier CY - Amsterdam AN - OPUS4-2781 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - Materialanalytik: Was leistet die Festkörper NMR T2 - Kolloquium, BAM CY - Berlin, Germany DA - 2002-01-30 PY - 2002 AN - OPUS4-2949 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - Was kann die NMR bei der Untersuchung von Kristallisationsvorgängen leisten: Eine kritische Wertung Deutsche Gesellschaft für Kristallographie, AK Nichtkristalline Strukturen T2 - XXIII Arbeitskreistagung CY - Jena, Germany DA - 2002-09-09 PY - 2002 AN - OPUS4-2950 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - Ringzuordnung der Kohlenstoffsignale von Cellulose mittels 2D-NMR T2 - DFG-Rundtischgespräch "Magnetische Resonanz zur Abstandsbestimmung und neue Methoden zur Steigerung von Sensitivität und Auflösung" CY - Hirschegg, Austria DA - 2002-09-18 PY - 2002 AN - OPUS4-2951 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - 170 NMR of Binary and Ternary Phosphate Glasses T2 - 7th Otto Schott Collquium CY - Jena, Germany DA - 2002-07-04 PY - 2002 AN - OPUS4-2954 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - Was lernt man aus NMR-Untersuchungen fester Bakteriencellulose? T2 - Biotechnologie-Kolloquium anlässlich des 10-jährigen Bestehens des Forschungszentrums für Medizintechnik und Biotechnologie e. V. CY - Bad Langensalza, Germany DA - 2004-06-30 PY - 2004 AN - OPUS4-4076 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - Das Bio- und Knochenmaterial Apatit: Zur Struktur von nanokristallinem Apatit und über die Bindung von Apatit im Knochen T2 - 10. MDR-Treffen, Universität Leipzig CY - Leipzig, Germany DA - 2004-07-12 PY - 2004 AN - OPUS4-4127 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Adorjan, I. A1 - Rosenau, Th. A1 - Potthast, A. A1 - Kosma, P. A1 - Mereiter, K. A1 - Pauli, Jutta A1 - Jäger, Christian T1 - Crystal and molecular structure of methyl 4-O-methyl-beta-D-ribo-hex-3-ulopyranoside N2 - Methyl 4-O-methyl-?-Image-ribo-hex-3-ulopyranoside (2), a model compound for partially oxidized anhydroglucose units in cellulose, was crystallized from CHCl3/n-hexane by vapor diffusion to give colorless plates. Crystal structure determination revealed the monoclinic space group P21 with Z=2C8H14O6 and unit cell parameters of a=8.404(2), b=4.5716(10), c=13.916(3) Å, and ?=107.467(4)°. The structure was solved by direct methods and refined to R=0.0476 for 1655 reflections and 135 parameters. The hexulopyranoside occurs in a distorted chair conformation. Both hydroxyls are involved in hydrogen bonding and form zigzag bond chains along the b-axis. One of the two hydrogen bonds is bifurcated. The solid-state 13C NMR spectrum of 2 exhibits eight carbon resonances, with well-separated signals for the two methoxyls (1-OMe: 55.72 ppm, 4-OMe: 61.25 ppm) and a keto resonance with relatively large downfield shift (206.90 ppm). Differences in the C-4 and the methoxyls’ chemical shifts in the solid and liquid states were found KW - Crystal structure KW - Solid-state NMR KW - Cellulose KW - Carbonyl groups PY - 2004 DO - https://doi.org/10.1016/j.carres.2004.01.006 SN - 0008-6215 SN - 1873-426X VL - 339 IS - 4 SP - 795 EP - 799 PB - Elsevier CY - Amsterdam AN - OPUS4-5341 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - 17O NMR of Phosphate Glasses and Ambiguities of Comparative XRD and NMR Studies of Phosphate Bioceramics T2 - American Ceramic Society, Glass & Optical Materials Division Fall Meeting CY - Corning, NY, USA DA - 2003-10-12 PY - 2003 AN - OPUS4-5312 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - Neues aus der Nanowelt: Über Strukturen, Oberflächen und die Mineral-Protein-Wechselwirkung in Biomaterialien T2 - 13. Keramiktag der BAM CY - Berlin, Germany DA - 2006-05-09 PY - 2006 AN - OPUS4-12388 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jäger, Christian A1 - Welzel, T. A1 - Meyer-Zaika, W. A1 - Epple, M. T1 - A solid-state NMR investigation of the structure of nanocrystalline hydroxyapatite N2 - Nanocrystalline hydroxyapatite (HAp) prepared by a precipitation route was investigated. The X-ray diffraction (XRD) powder patterns of the elongated nanocrystals with a typical diameter of about 10 nm and length of 30-50 nm (by transmission electron microscopy (TEM)) revealed the presence of HAp with significantly broadened XRD reflections. However, Ca deficiency was found, as the Ca/P ratio was 1.5 only (so-called calcium-deficient hydroxyapatite (CDHA)), and not 1.67. This Ca deficiency of nanocrystalline HAp is explained using NMR. It is shown unambiguously that (i) the nanocrystals consist of a crystalline core and a (disordered) surface region with a relative phosphate content of about 1:1, (ii) the crystalline core is HAp, and (iii) the surface region is dominated by hydrogen phosphate anions (with no hydroxyapatite-like structural motif) and structural water (hydrate). From the relative phosphate content and taking into account the crystal shape, the thickness of the surface layer along the main crystal axis could be estimated to be about 1 nm, and the average chemical composition of the surface layer has been determined. Finally, a Ca/P ratio of 1.52 was estimated from the NMR data that compares well with the value of 1.51 from chemical analysis. The important consequences are that the surface of nanocrystalline HAp has nothing in common with the bulk composition and that the chemistry of such materials (e.g. the binding of protein molecules to phosphate surfaces) must be reconsidered. KW - NMR KW - H-1 KW - P-31 KW - Biomineralization KW - Hydroxyapatite KW - Calcium phosphate KW - Nanoparticles PY - 2006 DO - https://doi.org/10.1002/mrc.1774 SN - 0749-1581 SN - 1097-458X VL - 44 IS - 6 SP - 573 EP - 580 PB - Wiley CY - Chichester AN - OPUS4-12366 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nofz, Marianne A1 - Pauli, Jutta A1 - Dreßler, Martin A1 - Jäger, Christian A1 - Altenburg, Wolfgang T1 - 27Al NMR Study of Al-Speciation in Aqueous Alumina-Sols N2 - A new method of preparing concentrated alumo-sols, the hydrolysis of Al-tri-sec-butylate in acidic aqueous media at 85°C, was studied in detail by varying the H2O/Al- and NO3 -/Al-ratios in wide ranges. The components of the sols were characterized by 27Al NMR spectroscopy. The pH-value depends on both the chosen H2O/Al- and NO3 -/Al-ratio and on the aging time of the sols and reflects the composition of the sols. Al13 polycations were detected in sols with a pH-value between 3.0 and 3.7. As a new result its presence was shown by NMR below 3.4. The Al13 content of the sols increased with pH and the maximum fraction of Al13 polycations was detected in the sol with the highest pH (3.7). Nearly 65% of the entire aluminium content of this solution is bound in the Al13 polycations. Hence, a new synthetic method for the preparation of Al13 ions containing sols was developed. Aging studies of the sols showed, that the Al13 polycations were more stable in solutions with higher pH-value. Al13 polycations were detected after an aging time of four months only in sols with a pH-value of 3.7. Tempering the aged sols at 40° to 80°C caused formation of Al13 and also of Al30 polycations. KW - Alumo-sol KW - Al13 polycations KW - Al-27 NMR spectroscopy PY - 2006 SN - 0928-0707 SN - 1573-4846 VL - 38 IS - 1 SP - 25 EP - 35 PB - Kluwer Academic Publ. CY - Dordrecht AN - OPUS4-12350 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - A solid state NMR study of the biomaterial nacre T2 - Rocky Mountain Conference on Analytical Chemistry CY - Breckenridge, CO, USA DA - 2006-07-24 PY - 2006 AN - OPUS4-12387 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - NMR of synthetic and natural biomaterials T2 - Seminar an der Universität Yokohama CY - Yokohama, Japan DA - 2006-06-19 PY - 2006 AN - OPUS4-12492 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jäger, Christian A1 - Maltsev, Sergey A1 - Karrasch, Andrea T1 - Progress of Structural Elucidation of Amorphous Calcium Phosphate (ACP) and Hydroxyapatite (HAp): Disorder and Surfaces as Seen by Solid State NMR KW - Hydroxyapatite KW - Amorphous calcium phosphate KW - Structural investigation KW - Surface KW - NMR PY - 2006 VL - 18 IS - 1 SP - 69 EP - 72 AN - OPUS4-11008 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nassif, N. A1 - Pinna, N. A1 - Gehrke, N. A1 - Antonietti, M. A1 - Jäger, Christian A1 - Cölfen, H. T1 - Amorphous layer around aragonite platelets in nacre KW - Nacre KW - NMR KW - Aragonite KW - Amorphous Surface KW - Protein binding PY - 2005 SN - 0027-8424 SN - 1091-6490 VL - 102 IS - 36 SP - 12653 EP - 12655 PB - National Academy of Sciences CY - Washington, DC AN - OPUS4-11009 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jäger, Christian A1 - Groom, N. S. A1 - Bowe, Elizabeth A. A1 - Horner, A. A1 - Davies, M. Elisabeth A1 - Murray, Rachel C. A1 - Duer, M. J. T1 - Investigation of the Nature of the Protein-Mineral Interface in Bone by Solid-State NMR N2 - Hydrogen-bearing species in the bone mineral environment were investigated using solid-state NMR spectroscopy of powdered bone, deproteinated bone, and B-type carbonated apatite. Using magic-angle spinning and cross-polarization techniques three types of structurally-bound water were observed in these materials. Two of these water types occupy vacancies within the apatitic mineral crystal in synthetic carbonated apatite and deproteinated bone and serve to stabilize these defect-containing crystals. The third water was observed at the mineral surface in unmodified bone but not in deproteinated bone, suggesting a role for this water in mediating mineral-organic matrix interactions. Direct evidence of monohydrogen phosphate in a 1H NMR spectrum of unmodified bone is presented for the first time. We obtained clear evidence for the presence of hydroxide ion in deproteinated bone by 1H MAS NMR. A 1H-31P heteronuclear correlation experiment provided unambiguous evidence for hydroxide ion in unmodified bone as well. Hydroxide ion in both unmodified and deproteinated bone mineral was found to participate in hydrogen bonding with neighboring water molecules and ions. In unmodified bone mineral hydroxide ion was found, through a 1H-31P heteronuclear correlation experiment, to be confined to a small portion of the mineral crystal, probably the internal portion. KW - NMR KW - Bone KW - Protein-mineral-interface PY - 2005 DO - https://doi.org/10.1529/biophysj.105.070243 SN - 0897-4756 SN - 1520-5002 VL - 17 IS - 12 SP - 3059 EP - 3061 PB - American Chemical Society CY - Washington, DC AN - OPUS4-11010 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hesse, S. A1 - Jäger, Christian T1 - Determination of the 13C chemical shift anisotropies of cellulose I and cellulose II N2 - The chemical shift anisotropies (CSAs) of cellulose I and I, the two crystalline constituents of bacterial cellulose produced by Acetobacter xylinum (DSM 14666), and regenerated cellulose II are reported for each of the spectroscopically resolved carbon resonances using the phase adjusted spinning sideband (PASS) experiment. The data are compared with experimental results using the recoupling of anisotropy information (RAI) technique and with theoretical calculations of the structure of cellulose, including the hydrogen bonding systems. KW - Acetobacter xylinum KW - Bacterial cellulose KW - Cellulose I KW - Cellulose II KW - Chemical shift anisotropy KW - CSA KW - C-13 NMR PY - 2005 DO - https://doi.org/10.1023/B:CELL.0000049407.56737.c7 SN - 0969-0239 SN - 1572-882X VL - 12 IS - 1 SP - 5 EP - 14 PB - Chapman & Hall CY - London AN - OPUS4-11011 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koudelka, L. A1 - Mosner, P. A1 - Zeyer, M. A1 - Jäger, Christian T1 - Structural study of PbO-B2O3-P2O5 glasses by NMR, Raman and infrared spectroscopy T2 - 19th International Congress on Glass CY - Edinburgh, Scotland, UK DA - 2001-07-01 PY - 2002 SN - 0-900682-39-6 N1 - Serientitel: Physics and chemistry of glasses – Series title: Physics and chemistry of glasses VL - 43C IS - 43C.2002 SP - 1 EP - 6 PB - Soc. of Glass Techn. CY - Sheffield AN - OPUS4-11012 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zeyer, M. A1 - Montagne, L. A1 - Kostoj, V. A1 - Palavit, G. A1 - Prochnow, D. A1 - Jäger, Christian T1 - 17O nuclear magnetic resonance study of Na2O-P2O5 glasses N2 - The preparation and structural investigation of 17O-enriched xNa2O–(100-x)P2O5 glasses (46.5<=x<=62.8) by nuclear magnetic resonance (NMR) is described. Enriched phosphoric acid was prepared by hydrolysis of PCl5 with 17O-enriched water and neutralized with sodium carbonate. The sodium metaphosphate was then melted at 800 °C for 15 h and quenched. Polyphosphate and ultraphosphate glass compositions were prepared by remelting the metaphosphate with sodium carbonate and phosphorus pentoxide, respectively. 31P magic angle sample spinning (MAS) NMR was used to determine the Na2O/P2O5 content in the glasses. 17O NMR spectra (quadrupole echo for non-rotating samples and multiple-quantum excitation for rotating samples (MQMAS)) show two oxygen sites in the samples with large quadrupolar coupling constants (4.7 and 7.7 MHz), in accordance with the high phosphorus electronegativity. According to the correlation of 17O quadrupolar constants with bond ionicity, these two components are attributed to bridging P–O–P and non-bridging P–O...Na oxygens. The average P–O–P bond angle is estimated with the quadrupolar asymmetry derived from the fit of the static echo spectra. The MQMAS spectrum shows a distribution of non-bridging oxygen chemical shifts, attributed to a variation of bond length and angle. PY - 2002 SN - 0022-3093 VL - 311 IS - 3 SP - 223 EP - 232 PB - North-Holland Publ. Co. CY - Amsterdam AN - OPUS4-11013 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rosenau, Th. A1 - Mereiter, K. A1 - Jäger, Christian A1 - Schmid, P. A1 - Kosma, P. T1 - Sulfonium ylides derived from 2-hydroxy-benzoquinones: crystal and molecular structure and their one-step conversion jinto Mannich bases by amine N-oxides N2 - Reaction of 2-hydroxy-para-benzoquinones with DMSO/Ac2O produced dimethylsulfonium ylides, of which crystal structures as well as solid and liquid state NMR spectra were recorded. The ylides react with tertiary methylamine N-oxides in a one-pot, multi-step process to 3-methylamino-substituted benzoquinones. The mechanism starts with a deoxygenative deprotonation of the amine N-oxides, followed by a formal electrophilic displacement of DMSO by the resulting carbonium–iminium ion. KW - Sulfonium ylides KW - Amine N-oxides KW - Crystal structure KW - Benzoquinones PY - 2004 DO - https://doi.org/10.1016/j.tet.2004.05.015 SN - 0040-4020 SN - 1464-5416 VL - 60 IS - 27 SP - 5719 EP - 5723 PB - Elsevier Science CY - Kidlington AN - OPUS4-11014 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zeyer-Düsterer, Michaela A1 - Montagne, L. A1 - Palavit, G. A1 - Jäger, Christian T1 - Combined 17O NMR and 11B-31P double resonance NMR studies of sodium borophosphate glasses N2 - 17O enriched sodium borophosphate glasses were prepared from isotopically enriched NaPO3 and H3BO3. These glasses have been studied by 17O, 11B and 31P NMR including 17O and 11B multiple quantum magic angle sample spinning (MQMAS), 11B–31P heteronuclear correlation (HETCOR) NMR and 11B 31P rotational echo double resonance (REDOR). For comparison, the crystalline borophosphates BPO4 and Na5B2P3O13 were included in the investigations. The latter compound shows three sharp 31P resonances at -0.2, -2 and -8 ppm and two BO4 sites that can only be resolved by MQMAS. The 17O NMR spectra were recorded using both the static echo method at medium magnetic field (9.4 T) as well as MAS and MQMAS methods at high field (17.6 T). In total, five oxygen sites were identified in these borophosphate glasses: P–O–P, NaO–P, P–O–B, B–O–B, NaO–B. However, these five sites are not present simultaneously in any of the glasses. The 17O MQMAS spectra prove that P–O–B links play a major role in borophosphate glasses. These results are confirmed by the complementary 11B MAS spectra that show the presence of asymmetric and symmetric trigonal groups BO3a and BO3s and two tetrahedral BO4 units. 11B 31P REDOR NMR is used to give independent information to assign the 11B lines to structural units present in the glasses. These REDOR measurements reveal that B–O–P bonds are present for each borate unit, including the BO3 groups. Particularly, a structural proposal for the two different BO4 resonances is given in terms of a different number of bonded phosphate tetrahedra. The 31P MAS spectra are usually broad and not well resolved. It is shown by 11B–31P HETCOR NMR that a possible structural assignment of a 31P signal at about -20 ppm to Q2 units as in binary sodium phosphate glasses is wrong and that the phosphate tetrahedron belonging to this resonance must be connected to borate groups KW - NMR KW - Sodium borophosphate glasses KW - Glass structure KW - NA5B2P3O13 KW - O-17 NMR KW - REDOR KW - MQMAS PY - 2005 DO - https://doi.org/10.1016/j.ssnmr.2004.06.009 SN - 0926-2040 SN - 1527-3326 VL - 27 IS - 1-2 SP - 50 EP - 64 PB - Academ. Press CY - Orlando, Fla. AN - OPUS4-11015 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Koudelka, L. A1 - Mosner, P. A1 - Zeyer, M. A1 - Jäger, Christian T1 - Structure and properties of mixed sodium-lead borophosphate glasses N2 - Mixed sodium–lead borophosphate glasses were prepared in two compositional series xNa2O–(50 - x)PbO–10B2O3–40P2O5 and xNa2O–(50 - x)PbO–20B2O3–30P2O5 with x = 0, 10, 20, 30, 40 and 50 mol% Na2O. Their density decreases and molar volume increases slightly with increasing Na2O content. Chemical durability decreases steeply for glasses containing 40–50 mol% Na2O, whereas glass transition temperatures reveals a minimum at the glasses with 30–40 mol% Na2O. The 31P MAS NMR and Raman spectra of the first series show that with increasing Na2O content the ratio of structural units Q2/Q1 slowly increases and the Q2 phosphate units and BO4 units prevail in the structure of these glasses. In the second series of glasses Q1 diphosphate units together with BO4 and small number of BO3 units form structural network of glasses. The replacement of PbO by Na2O results in higher ionicity of bonding interactions between compensating cations and the anionic network. The lower cation field strength of Na+ ions results in the observed downfield shift of ? (31P) values in Na-rich glasses and narrower vibrational bands in their Raman spectra. PY - 2005 DO - https://doi.org/10.1016/j.jnoncrysol.2005.01.015 SN - 0022-3093 VL - 351 IS - 12-13 SP - 1039 EP - 1045 PB - North-Holland Publ. Co. CY - Amsterdam AN - OPUS4-11016 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - NMR-Untersuchungen zur Struktur nanoskaliger Biomaterialien: Über Strukturen an Oberflächen und die Mineral-Protein-Wechselwirkung am Knochen T2 - Seminarvortrag Makromolekulare Chemie, AK Blümich, RWTH CY - Aachen, Germany DA - 2005-06-14 PY - 2005 AN - OPUS4-11512 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - A solid state NMR study of the biomaterial nacre T2 - GDCh-Fachgruppe-Jahrestagung 2005 CY - Mainz, Germany DA - 2005-09-28 PY - 2005 AN - OPUS4-11519 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian A1 - Duer, M. J. T1 - Solid-state NMR: a tool for probing the protein-mineral interface in biomaterials T2 - Gordon Conference on Biomineralization CY - New London, NH, USA DA - 2006-07-30 PY - 2006 AN - OPUS4-11521 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - NMR-Untersuchungen zur Struktur nanoskaliger Biomaterialien: Phosphate und Carbonate T2 - DFG-Rundtischgespräch "Magnetische Spektroskopie der Struktur und Dynamik nano- und mesoskopischer Systeme" CY - Hirschegg, Austria DA - 2005-09-04 PY - 2005 AN - OPUS4-11522 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - NMR of nanoscopic inorganic biomaterials: on bulk structures, surfaces and the mineral-protein interface T2 - Graduiertenkolleg "Magnetische Resonanz", Universität Stuttgart CY - Stuttgart, Germany DA - 2005-11-07 PY - 2005 AN - OPUS4-11502 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian T1 - Nanoskalige Calciumphosphate, Oberflächenstrukturen und Wechselwirkung mit organischen Molekülen. Was kann die NMR? T2 - Jahrestagung der Deutschen Gesellschaft für Biomaterialien e. V. CY - Würzburg, Germany DA - 2005-10-07 PY - 2005 AN - OPUS4-11505 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Spange, St. A1 - Müller, H. A1 - Jäger, Christian A1 - Bellmann, C. T1 - Fabrication of carbon/silica hybrid materials using cationic polymerization and the sol-gel process PY - 2002 SN - 1022-1360 SN - 0258-0322 SN - 1521-3900 VL - 177 IS - 1 SP - 111 EP - 124 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-11017 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -