TY - JOUR A1 - Al-Terkawi, Abdal-Azim A1 - Scholz, G. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Reinsch, Stefan A1 - Kemnitz, E. A1 - Emmerling, Franziska T1 - Ca- and Sr- tetrafluoroisophthalates: mechanochemical synthesis, characterization, and ab initio structure determination JF - DALTON TRANSACTIONS N2 - New fluorinated coordination polymers were prepared mechanochemically by milling the alkaline earth metal hydroxides MII(OH)2·xH2O (MII: Ca, Sr) with tetrafluoroisophthalic acid (H2mBDC-F4). The structures of [{Ca(mBDC-F4)(H2O)2}·H2O] and [{Sr(mBDC-F4)(H2O)2}·H2O] were determined based on ab initio calculations and their powder X-ray diffraction (PXRD) data. The compounds are isomorphous and crystallize in the orthorhombic space group P212121. The determined structures were validated by using extended X-ray absorption (EXAFS) data. The new materials were thoroughly characterized using elemental analysis, thermal analysis, magic angle spinning NMR, and attenuated total reflection-infrared spectroscopy. Further characterization methods such as BET, dynamic vapor sorption, and scanning electron microscopy imaging were also used. Our investigations indicate that mechanochemistry is an efficient method for preparing such materials. KW - Mechanochemistry KW - In situ KW - XRD KW - Coordination polymers PY - 2017 UR - http://pubs.rsc.org/-/content/articlehtml/2017/dt/c7dt00734e DO - https://doi.org/10.1039/c7dt00734e VL - 46 IS - 18 SP - 6003 EP - 6012 AN - OPUS4-41516 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nguyen, Thi Yen A1 - Roessler, Ernst A1 - Rademann, Klaus A1 - Emmerling, Franziska T1 - Control of organic polymorph formation: crystallization pathways in acoustically levitated droplets JF - Zeitschrift für Kristallographie - Crystalline Materials N2 - Theoretical and experimental studies indicate that crystal nucleation can take more complex pathways than expected on the ground of the classical nucleation theory. Among these pathways are the formation of pre-nucleation clusters and amorphous precursor phases. A direct in situ observation of the different pathways of nucleation from solution is challenging since the paths can be influenced by heterogeneous nucleation sites, such as container walls. Here, we provide insights into the crystallization process using the in situ combination of an acoustic levitator, Raman spectroscopy, and X-ray scattering. The contactless sample holder enables the observation of homogeneous crystallization processes and the detection of intermediates and final crystalline forms. We provide evidence for the existence of multiple pathways of nucleation based on the investigation of the crystallization of organic molecules from different solvents. Starting from a diluted solution, a supersaturation is reached during the experiment due to the evaporation of the solvent. The highly supersaturated solution reveals different pathways of crystallization. Depending on the degree of supersaturation either the thermodynamically stable or the metastable crystal form is observed. KW - Crystallization KW - In situ XRD KW - Polymorphism KW - Polyamorphism KW - Raman spectroscopy PY - 2017 DO - https://doi.org/10.1515/zkri-2016-1964 SN - 2194-4946 SN - 2196-7105 VL - 232 IS - 1-3 SP - 15 EP - 24 PB - De Gruyter CY - Berlin AN - OPUS4-39708 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wilke, Manuel A1 - Kabelitz, Anke A1 - Zimathies, Annett A1 - Rademann, K. A1 - Emmerling, Franziska T1 - Crystal structure and in situ investigation of a mechanochemical synthesized 3D zinc N-(phosphonomethyl)glycinate JF - Journal of Materials Science N2 - The mechanochemical synthesis of the zinc N-(phosphonomethyl)glycinate Zn(O₃PCH₂NH₂CH₂CO₂) H₂O is presented. The structure was solved from powder X-ray diffraction (PXRD) data. In the three-dimensional pillared structure, the Zn atoms are coordinated tetrahedrally. In situ investigations of the reaction process with synchrotron PXRD and Raman spectroscopy reveal a two-step process including the formation of an intermediate. KW - Mechanochemistry KW - Metal phosphonate KW - In situ PY - 2017 DO - https://doi.org/10.1007/s10853-017-1121-7 SN - 0022-2461 SN - 1573-4803 VL - 52 IS - 20 SP - 12013 EP - 12020 PB - Springer CY - New York AN - OPUS4-41490 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Matoga, D. A1 - Roztocki, K. A1 - Wilke, Manuel A1 - Emmerling, Franziska A1 - Oszajca, M. A1 - Fitta, M. A1 - Bałanda, M. T1 - Crystalline bilayers unzipped and rezipped: solid-state reaction cycle of a metal–organic framework with triple rearrangement of intralayer bonds JF - CrystEngComm N2 - We present a series of remarkable structural transformations for a family of layered metal–organic frameworks (MOFs) in a three-step solid-state reaction cycle. The cycle represents new dynamic behavior of 2D coordination polymers and involves the sequence of reactions: {[Mn2(ina)4(H2O)2]·2EtOH}n (JUK-1) → {(NH4)2[Mn(ina)2(NCS)2]}n·xH2O (JUK-2) → {[Mn2(ina)2(Hina)2(NCS)2]}n (JUK-3) → JUK-1 (Hina = isonicotinic acid), each accompanied by rearrangement of intralayer coordination bonds and each induced by a different external stimulus. In situ investigation of the first step of the cycle by combined synchrotron X-ray diffraction and Raman spectroscopy reveals direct mechanochemical unzipping of JUK-1 bilayers to respective JUK-2 layers with reaction rates dependent on the milling conditions. In contrast, the reverse zipping of JUK-2 layers involves two steps and proceeds through a new MOF (JUK-3) whose structure was elucidated by powder X-ray diffraction. Magnetic measurements confirm conversions of manganese nodes in the reaction cycle. The findings indicate the possibility of developing coordination-based assemblies with large structural responses for use in smart stimuli-responsive systems and sensor technologies. KW - Mechanochemistry KW - In situ KW - XRD KW - MOF PY - 2017 UR - http://pubs.rsc.org/is/content/articlehtml/2017/ce/c7ce00655a DO - https://doi.org/10.1039/C7CE00655A VL - 19 SP - 2987 EP - 2995 AN - OPUS4-41517 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Seidel, R. A1 - Kraffert, K. A1 - Kabelitz, Anke A1 - Pohl, M.N. A1 - Kraehnert, R. A1 - Emmerling, Franziska A1 - Winter, B. T1 - Detection of the electronic structure of iron-(III)-oxo oligomers forming in aqueous solutions JF - Physical Chemistry Chemical Physics N2 - The nature of the small iron-oxo oligomers in iron-(III) aqueous solutions has a determining effect on the chemical processes that govern the formation of nanoparticles in aqueous phase. Here we report on a liquid-Jet photoelectron-spectroscopy experiment for the investigation of the electronic structure of the occurring iron-oxo oligomers in FeCl3 aqueous solutions. The only iron species in the as-prepared 0.75 M solution are Fe3+ monomers. Addition of NaOH initiates Fe3+ hydrolysis which is followed by the formation of iron-oxo oligomers. At small enough NaOH concentrations, corresponding to approximately [OH]/[Fe] = 0.2–0.25 ratio, the iron oligomers can be stabilized for several hours without engaging in further aggregation. Here, we apply a combination of non-resonant as well as iron 2p and Oxygen 1s resonant photoelectron spectroscopy from a liquid microjet to detect the electronic structure of the occurring species. Specifically, the oxygen 1s partial electron yield X-ray absorption (PEY-XA) spectra are found to exhibit a peak well below the onset of liquid water and OH (aq) absorption. The iron 2p absorption gives rise to signal centered between the main absorption bands typical for aqueous Fe3+. Absorption bands in both PEY-XA spectra are found to correlate with an enhanced photoelectron Peak near 20 eV binding energy, which demonstrates the sensitivity of resonant photoelectron (RPE) spectroscopy to mixing between iron and ligand orbitals. These various signals from the iron-oxo oligomers exhibit Maximum intensity at [OH]/[Fe] = 0.25 ratio. For the same ratio, we observe changes in the pH as well as in complementary Raman spectra, which can be assigned to the Transition from monomeric to oligomeric species. At approximately [OH]/[Fe] = 0.3 we begin to observe particles larger than 1 nm in radius, detected by small-angle X-ray scattering. KW - Iron-oxo oligomers KW - XPS KW - Electronic structure PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-433468 DO - https://doi.org/10.1039/c7cp06945f SN - 1463-9076 SN - 1463-9084 VL - 19 IS - 48 SP - 32226 EP - 32234 AN - OPUS4-43346 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stroh, Julia A1 - Emmerling, Franziska ED - Plank, J. ED - Lei, L. T1 - Direct insight into the admixture activity during cement hydration using levitated droplets T2 - Conference proceedings of the 2nd International Conference on Polycarboxylate Superplasticizers (PCE 2017) N2 - Chemical admixtures are widely used to adjust properties of the cementitious mixtures. Different superplasticizers (SP) are typically added to improve the flowability of the fresh cement paste. Their working period is the initial stage of the cement hydration from its beginning until stiffening. Currently, polycarboxylate-based SP (PCE-SP) are the most effective ones. They can act beyond their aimed function causing changes in the hydration course, e. g. retardation effects. The exact mechanisms and influencing factors are still under investigation. However, the occurrence of the retardation effect indicates the involvement of PCE in the hydration reactions. Some observations indicate, that the retardation depends on the type, molecular structure and concentration of PCE, and the presence of other admixtures (stabiliser, ST). These factors influence further the working time of admixture and its amount related efficacy in the flow improvement. We investigate the cement hydration process in situ in levitated droplets. High resolution synchrotron X-ray diffraction allows gathering temporal course of the hydration reactions. The measurement setup is based on an ultrasonic levitator allowing in situ investigation of the temporal changes of the phase composition in the hydrating cementitious system. Further, the hydration can be followed ab initio avoiding the time loss for the sample preparation and filling in the sample holder. The collected data allows to conclude about the mechanisms of the admixture action and their involvement into the ongoing hydration process. T2 - 2nd International Conference on Polycarboxylate Superplasticizers (PCE 2017) CY - München, Germany DA - 28.09.2017 KW - Portland cement KW - Initial hydration KW - Acoustic levitator KW - Admixtures KW - Time resolution PY - 2017 SN - 978-3-9816240-6-9 SP - 185 EP - 193 AN - OPUS4-43167 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wilke, Manuel A1 - Bach, S. A1 - Gorelik, T. A1 - Kolb, U. A1 - Tremel, W. A1 - Emmerling, Franziska T1 - Divalent metal phosphonates – new aspects for syntheses, in situ characterization and structure solution JF - Zeitschrift für Kristallographie - Crystalline Materials N2 - Divalent metal phosphonates are promising hybrid materials with a broad field of application. The rich coordination chemistry of the phosphonate linkers enables the formation of structures with different dimensionalities ranging from isolated complexes and layered structures to porous frameworks incorporating various functionalities through the choice of the building blocks. In brief, metal phosphonates offer an interesting opportunity for the design of multifunctional materials. Here, we provide a short review on the class of divalent metal phosphonates discussing their syntheses, structures, and applications. We present the advantages of the recently introduced mechanochemical pathway for the Synthesis of divalent phosphonates as a possibility to generate new, in certain cases metastable compounds. The benefits of in situ investigation of synthesis mechanisms as well as the implementation of sophisticated methods for the structure analysis of the resulting compounds are discussed. KW - Metal phosphonate KW - Mechanochemistry PY - 2017 DO - https://doi.org/10.1515/zkri-2016-1971 SN - 2194-4946 SN - 2196-7105 VL - 232 IS - 1-3 SP - 209 EP - 222 PB - De Gruyter AN - OPUS4-40003 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - In situ investigations of mechanochemical reactions N2 - Mechanochemistry is increasingly used for synthesizing soft matter materials including metal organic compounds and cocrystals.1,2 The ever-increasing interest in this method is contrasted by a limited mechanistic understanding of the mechanochemical reactivity and selectivity. Time-resolved in situ investigations of milling reactions provide direct insights in the underlying mechanisms.3,4 We recently introduced a setup enabling in situ investigation of mechanochemical reactions using synchrotron XRD combined with Raman spectroscopy (Fig.1a) The specific combination allows to study milling processes comprehensively on the level of the molecular and crystalline structure and thus obtaining reliable data for mechanistic studies. In this talk I will discuss our recent results investigating the formation of (polymorphic) cocrystals.6-7 First investigations of a mechanochemical synthesis under controlled temperature (Fig 2a) which allow determining the activation barrier are presented.8 Furthermore, in situ Raman spectroscopy coupled with thermography revealed a low temperature increase during milling reactions due to the mechanical impact and clear temperature increases as a result of the reaction heat. T2 - Kolloquium Anorganische und Analytische Chemie Universität Freiburg CY - Freiburg, Germany DA - 20.12.2017 KW - In situ KW - Mechanochemistry KW - Rietveld PY - 2017 AN - OPUS4-43566 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska A1 - Kulla, Hannes A1 - Wilke, Manuel T1 - In situ investigations of mechanochemical reactions - new insights in formation pathways N2 - Mechanochemistry is increasingly used for synthesizing soft matter materials including metal organic compounds and cocrystals. The ever-increasing interest in this method is contrasted by a limited mechanistic understanding of the mechanochemical reactivity and selectivity. Time-resolved in situ investigations of milling reactions provide direct insights in the underlying mechanisms. We recently introduced a setup enabling in situ investigation of mechanochemical reactions using synchrotron XRD combined with Raman spectroscopy. The specific combination allows to study milling processes comprehensively on the level of the molecular and crystalline structure and thus obtaining reliable data for mechanistic studies. In situ Raman spectroscopy coupled with thermography revealed a low temperature increase during milling reactions due to the mechanical impact and clear temperature increases because of the reaction heat. Based on the data, temperature rises as postulated in the magma plasma and hot spot theory can be excluded for soft matter milling syntheses. Our results indicate that in situ investigation of milling reactions offer a new approach to tune and optimize mechanochemically synthesized compounds. T2 - Wissenschaftsforum Chemie CY - Berlin, Germany DA - 10.09.17 KW - Mechanochemistry KW - In situ PY - 2017 AN - OPUS4-43563 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - In situ investigations of mechanochemical syntheses: New insights in formation pathways N2 - Mechanochemistry is increasingly used for synthesizing soft matter materials including metal organic compounds and cocrystals.1,2 The ever-increasing interest in this method is contrasted by a limited mechanistic understanding of the mechanochemical reactivity and selectivity. Time-resolved in situ investigations of milling reactions provide direct insights in the underlying mechanisms.3,4 We recently introduced a setup enabling in situ investigation of mechanochemical reactions using synchrotron XRD combined with Raman spectroscopy (Fig.1a) The specific combination allows to study milling processes comprehensively on the level of the molecular and crystalline structure and thus obtaining reliable data for mechanistic studies. In this talk I will discuss our recent results investigating the formation of (polymorphic) cocrystals. T2 - CF@Bo2017 Crystal Forms Bologna 2017 CY - Bologna, Italy DA - 04.06.2017 KW - Mechanochemistry PY - 2017 AN - OPUS4-43567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -