TY - JOUR
A1 - Schlögl, Johanna
A1 - Goldammer, Ole
A1 - Bader, Julia
A1 - Emmerling, Franziska
A1 - Riedel, Sebastian
T1 - Introducing AFS ([Al(SO3F)3]x) – a thermally stable, readily available, and catalytically active solid Lewis superacid
JF - Chemical Science
N2 - This paper introduces the thermally stable, solid Lewis superacid aluminium tris(fluorosulfate) (AFS), that is easy-to-synthesize from commercially available starting materials. Its applicability, e.g. in catalytic C–F bond activations, is shown.
KW - Lewis Acid
KW - C-F activation
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601001
DO - https://doi.org/10.1039/D4SC01753F
SN - 2041-6520
SP - 1
EP - 7
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-60100
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Manoharan, Deepak
A1 - Ranjan, Subham
A1 - Emmerling, Franziska
A1 - Bhattacharya, Biswajit
A1 - Takamizawa, Satoshi
A1 - Ghosh, Soumyajit
T1 - Elasto-plastic behaviour with reversible thermosalient expansion in acrylonitrile-based organic crystals
JF - Journal of Materials Chemistry C
N2 - Crystalline materials that exhibit reversible mechanical responses upon exposure to external stimuli have garnered significant attention owing to their potential applications in various fields. Herein, we report a crystal of (2Z,2′Z)-2,2′-(1,4-phenylene)bis(3-(4-bromophenyl)acrylonitrile) (DSBr), which displays simultaneous elasto-plastic behaviour and reversible thermosalient effects. While elasto-plastic behaviour is attributed to underlying packing features, reversible thermosalient expansion is attributed to uniaxial expansion mediated by heat. Exceptional length increase and contraction upon cooling is due to the restorative nature of weak interactions through a cooperative effect. The cooperative movement of molecules is reflected in the unidirectional expansion of the habit plane. Thermosalient reversible expansion–contraction in elasto-plastic crystals have not been discussed in the literature so far. Detailed analysis reported herein provides a comprehensive understanding of the underlying mechanism of flexibility and thermosalient responses. This crystal's unique blend of reversible thermal expansion with flexibility holds substantial promise for applications in flexible thermal actuators.
KW - Materials Chemistry
KW - General Chemistry
PY - 2024
DO - https://doi.org/10.1039/D3TC04272C
SN - 2050-7526
SP - 1
EP - 11
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-59527
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Goswami, Juli Nanda
A1 - Haque, Najirul
A1 - Seikh, Asiful H.
A1 - Bhattacharya, Biswajit
A1 - Emmerling, Franziska
A1 - Bar, Nimai
A1 - Ifseisi, Ahmad A.
A1 - Biswas, Surajit
A1 - Dolai, Malay
T1 - Carboxylative cyclization of propargyl alcohols with carbon dioxide for the synthesis of α-alkylidene cyclic carbonates in presence of Co(III) schiff base complex catalyst
JF - Journal of Molecular Structure
N2 - A cobalt(III) complex, [Co(L)3](DMF) (1) of Schiff base ligand HL, 2-((E)-(benzylimino)methyl)-4-bromophenol is prepared and single crystal X-ray structural analysis have also been performed. The structures of complex 1 showed hexa-coordinated mononuclear systems that adopt octahedral geometry. The complex has also exhibited the supramolecular networks through non-covalent interactions like H-bonding, C–Hπ stacking. Moreover, the complex 1 is very effective in the catalytic fixation of carbon dioxide in propergyl alcohols to produce α-alkylidene cyclic carbonates. The catalytic production of α-alkylidene cyclic carbonates have been carried out through carboxylative cyclization of propargyl alcohols using CO2 balloon of 1 atm pressure at 80 ◦C. Solvent free condition (green synthesis) made this catalytic protocol eco-friendly towards the environment. Utilizing various substrates of propargyl alcohols moderate to high percentage yield (62–95%) of respective α-alkylidene cyclic carbonates product have been isolated over this catalytic reaction. Besides, the theoretical calculations (DFT) was performed for the prediction of probable mechanism of the catalytic reaction
KW - Catalytic fixation of carbon dioxide
KW - Carboxylative cyclization of propargyl alcohols
KW - Cobalt (III) Schiff base complex
KW - X-ray crystal analysis
PY - 2024
DO - https://doi.org/10.1016/j.molstruc.2023.136868
SN - 0022-2860
VL - 1296
IS - Part 1
SP - 1
EP - 8
PB - Elsevier B.V.
AN - OPUS4-58947
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Stawski, Tomasz
A1 - Karafiludis, Stephanos
A1 - Pimentel, Carlos
A1 - Montes-Hernández, German
A1 - Kochovski, Zdravko
A1 - Bienert, Ralf
A1 - Weimann, Karin
A1 - Emmerling, Franziska
A1 - Scoppola, Ernesto
A1 - Van Driessche, Alexander E.S.
T1 - Solution-driven processing of calcium sulfate: The mechanism of the reversible transformation of gypsum to bassanite in brines
JF - Journal of Cleaner Production
N2 - Here, we show that calcium sulfate dihydrate (gypsum) can be directly, rapidly and reversibly converted to calcium sulfate hemihydrate (bassanite) in high salinity solutions (brines). The optimum conditions for the efficient production of bassanite in a short time (<5 min) involve the use of brines with c(NaCl) > 4 M and maintaining a temperature, T > 80 °C. When the solution containing bassanite crystals is cooled down to around room temperature, eventually gypsum is formed. When the temperature is raised again to T > 80 °C, bassanite is rapidly re-precipitated. This contrasts with the better-known behaviour of the bassanite phase in low-salt environments. In low-salinity aqueous solutions, bassanite is considered to be metastable with respect to gypsum and anhydrite, and therefore gypsum-to-bassanite conversion does not occur in pure water. Interestingly, the high-salinity transformation of gypsum-to-bassanite has been reported by many authors and used in practice for several decades, although its very occurrence actually contradicts numerical thermodynamic predictions regarding solubility of calcium sulfate phases. By following the evolution of crystalline phases with in situ and time-resolved X-ray diffraction/scattering and Raman spectroscopy, we demonstrated that the phase stability in brines at elevated temperatures was inaccurately represented in the thermodynamic databases. Most notably for c(NaCl) > 4 M, and T > 80 °C gypsum becomes readily more soluble than bassanite, which induces the direct precipitation of the latter from gypsum. The fact that these transformations are controlled by the solution provides extensive opportunities for precise manipulation of crystal formation. Our experiments confirmed that bassanite remained the sole crystalline phase for many hours before reverting into gypsum. This property is extremely advantageous for practical processing and efficient crystal extraction in industrial scenarios.
KW - Industrial and Manufacturing Engineering
KW - Strategy and Management
KW - General Environmental Science
KW - Renewable Energy, Sustainability and the Environment
KW - Building and Construction
KW - Calcium sulfate
KW - Gypsum
KW - Bassanite
KW - Scattering
KW - Raman
KW - In situ
KW - Synchrotron
KW - BESSY
KW - MySpot
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-594698
UR - https://www.sciencedirect.com/science/article/pii/S0959652624004591#appsec1
DO - https://doi.org/10.1016/j.jclepro.2024.141012
SN - 0959-6526
VL - 440
SP - 1
EP - 12
PB - Elsevier B.V.
AN - OPUS4-59469
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zuffa, Caterina
A1 - Cappuccino, Chiara
A1 - Casali, Lucia
A1 - Emmerling, Franziska
A1 - Maini, Lucia
T1 - Liquid reagents are not enough for liquid assisted grinding in the synthesis of (AgBr)(n-pica) n
JF - Physical Chemistry Chemical Physics
N2 - This study investigates the mechanochemical reactions between AgBr 3-picolylamine and 4-picolylamine. The use of different stoichiometry ratios of the reagents allows [(AgBr)(n-pica)]n and [(AgBr)2(n-pica)]n to be obtained, and we report the new structures of [(AgBr)2(3-pica)]n and [(AgBr)2(4-pica)]n which are characterized by the presence of the following: (a) infinite inorganic chains, (b) silver atom coordinated only by bromide atoms and (c) argentophilic interactions. Furthermore, we studied the interconversion of [(AgBr)(n-pica)]n/[(AgBr)2(n-pica)]n by mechanochemical and thermal properties. The in situ experiments suggest that [(AgBr)(3-pica)]n is kinetically favoured while [(AgBr)2(3-pica)]n is converted into [(AgBr)(3-pica)]n only with a high excess of the ligand. Finally, the liquid nature of the ligands is not sufficient to assist the grinding process, and the complete reaction is observed with the addition of a small quantity of acetonitrile.
KW - Mechanochemistry
KW - Complex
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-594755
DO - https://doi.org/10.1039/d3cp04791a
SN - 1463-9076
SP - 1
EP - 10
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-59475
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Heinekamp, Christian
A1 - Kneiske, Sönke
A1 - Guilherme Buzanich, Ana
A1 - Ahrens, Mike
A1 - Braun, Thomas
A1 - Emmerling, Franziska
T1 - A fluorolytic sol-gel route to access an amorphous Zr fluoride catalyst: A useful tool for C-F bond activation
JF - Catalysis Science & Technology
N2 - A route to a ZrF4 catalyst active in room temperature Friedel–Crafts and dehydrofluorination reactions was developed via a fluorolytic sol–gel route, which was followed by a postfluorination step using a stream of CHClF2. The behaviour of different Zr(IV) precursors in a sol–gel reaction with anhydrous isopropanol/HF solution was investigated. The subsequent post-fluorination step was optimised in its temperature ramp and confirmed the necessity of a fluorination of the generated xerogels to obtain catalytic activity. The process is discussed in the context of the analysis of the materials using Brunauer–Emmett–Teller analysis (BET), powder X-ray diffraction (XRD), infrared spectroscopy (IR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The local structure of the amorphous catalyst was elucidated by extended X-ray absorption fine structure spectroscopy (EXAFS).
KW - Catalysis
KW - Heterogeneous catalysis
KW - C-F bond activation
KW - Postfluorination
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-593433
DO - https://doi.org/10.1039/D3CY01439H
SN - 2044-4761
SP - 1
EP - 8
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-59343
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Nag, Sayak
A1 - Emmerling, Franziska
A1 - Tothadi, Srinu
A1 - Bhattacharya, Biswajit
A1 - Ghosh, Soumyajit
T1 - Distinct photomechanical responses of two new 1,3-dimethylbarbituric acid derivative crystals
JF - CrystEngComm
N2 - We demonstrate two distinct photomechanical responses (i.e. photomechanical bending and photosalient bursting) of two new 1,3-dimethylbarbituric acid derivative crystals based on tailoring their substituents and the modulation of their spacers.
KW - Crystal engineering
KW - Fexible crystals
PY - 2024
DO - https://doi.org/10.1039/D4CE00233D
SP - 1
EP - 12
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-60141
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Cakir, Cafer Tufan
A1 - Bogoclu, Can
A1 - Emmerling, Franziska
A1 - Streli, Christina
A1 - Guilherme Buzanich, Ana
A1 - Radtke, Martin
T1 - Machine learning for efficient grazing-exit x-ray absorption near edge structure spectroscopy analysis: Bayesian optimization approach
JF - Machine Learning: Science and Technology
N2 - In materials science, traditional techniques for analyzing layered structures are essential for obtaining information about local structure, electronic properties and chemical states. While valuable, these methods often require high vacuum environments and have limited depth profiling capabilities. The grazing exit x-ray absorption near-edge structure (GE-XANES) technique addresses these limitations by providing depth-resolved insight at ambient conditions, facilitating in situ material analysis without special sample preparation. However, GE-XANES is limited by long data acquisition times, which hinders its practicality for various applications. To overcome this, we have incorporated Bayesian optimization (BO) into the GE-XANES data acquisition process. This innovative approach potentially reduces measurement time by a factor of 50. We have used a standard GE-XANES experiment, which serve as reference, to validate the effectiveness and accuracy of the BO-informed experimental setup. Our results show that this optimized approach maintains data quality while significantly improving efficiency, making GE-XANES more accessible to a wider range of materials science applications.
KW - Machine Learning
KW - GE-XANES
KW - Bayesian Optimization
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603955
DO - https://doi.org/10.1088/2632-2153/ad4253
VL - 5
IS - 2
SP - 1
EP - 12
PB - IOP Publishing
AN - OPUS4-60395
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Das, Prasenjit
A1 - Chakraborty, Gouri
A1 - Friese, Nico
A1 - Roeser, Jérôme
A1 - Prinz, Carsten
A1 - Emmerling, Franziska
A1 - Schmidt, Johannes
A1 - Thomas, Arne
T1 - Heteropolyaromatic Covalent Organic Frameworks via One-Pot Multicomponent Reactions
JF - Journal of the American Chemical Society
N2 - Multicomponent reactions (MCRs) offer a platform to create different chemical structures and linkages for highly stable covalent organic frameworks (COFs). As an illustrative example, the multicomponent Povarov reaction generates 2,4-phenylquinoline from aldehydes and amines in the presence of electron-rich alkenes. In this study, we introduce a new domino reaction to generate unprecedented 2,3-phenylquinoline COFs in the presence of epoxystyrene. This work thus presents, for the first time, structural isomeric COFs produced by multicomponent domino and Povarov reactions. Furthermore, 2,3-phenylquinolines can undergo a Scholl reaction to form extended aromatic linkages. With this approach, we synthesize two thermally and chemically stable MCR-COFs and two heteropolyaromatic COFs using both domino and in situ domino and Scholl reactions. The structure and properties of these COFs are compared with the corresponding 2,4-phenylquinoline-linked COF and imine-COF, and their activity toward benzene and cyclohexane sorption and separation is investigated. The position of the pendant phenyl groups within the COF pore plays a crucial role in facilitating the industrially important sorption and separation of benzene over cyclohexane. This study opens a new avenue to construct heteropolyaromatic COFs via MCR reactions.
KW - COF
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604038
DO - https://doi.org/10.1021/jacs.4c02551
SP - 1
EP - 9
PB - American Chemical Society (ACS)
AN - OPUS4-60403
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Villajos Collado, José Antonio
A1 - Bienert, M.
A1 - Gugin, Nikita
A1 - Emmerling, Franziska
A1 - Maiwald, Michael
T1 - A database to select affordable MOFs for volumetric hydrogen cryoadsorption considering the cost of their linkers
JF - Materials advances
N2 - Physical adsorption at cryogenic temperature (cryoadsorption) is a reversible mechanism that can reduce the pressure of conventional compressed gas storage systems. Metal–organic framework (MOF) materials are remarkable candidates due to the combination of high specific surface area and density which, in some cases, provide a high volumetric storage capacity. However, such extensive use of MOFs for this application requires the selection of affordable structures, easy to produce and made from feasible metallic and organic components. Herein, we introduce a MOF database detailing the crystallographic and porous properties of 3600 existing MOFs made from industrially relevant metals and their organic composition. The comparison of the available minimum costs of linkers allowed the creation of a database to select affordable structures with high potential for volumetric hydrogen storage by cryoadsorption, considering their composition based on individual or mixed building blocks. A user inter� face, available online, facilitates the selection of MOFs based on the properties or names of structures and linkers.
KW - MOF´s
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-583619
DO - https://doi.org/10.1039/d3ma00315a
VL - 4
IS - 18
SP - 4226
EP - 4237
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-58361
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Scheurrell, Kerstin
A1 - B. Martins, Inês C.
A1 - Murray, Claire
A1 - Emmerling, Franziska
T1 - Exploring the role of solvent polarity in mechanochemical Knoevenagel condensation: in situ investigation and isolation of reaction intermediates
JF - Physical Chemistry Chemical Physics
N2 - Mechanochemistry has proven to be a highly effective method for the synthesis of organic compounds. We studied the kinetics of the catalyst-free Knoevenagel reaction between 4-nitrobenzaldehyde and malononitrile, activated and driven by ball milling. The reaction was investigated in the absence of solvents (neat grinding) and in the presence of solvents with different polarities (liquid-assisted grinding). The reaction was monitored using time-resolved in situ Raman spectroscopy and powder X-ray diffraction (PXRD). Our results indicate a direct relationship between solvent polarity and reaction kinetics, with higher solvent polarity leading to faster product (2-(4-nitrobenzylidone)malononitrile) formation. For the first time, we were able to isolate and determine the structure of an intermediate 2-(hydroxy(4-nitrophenyl)methyl)malononitrile based on PXRD data.
KW - Physical and Theoretical Chemistry
KW - General Physics and Astronomy
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-588071
DO - https://doi.org/10.1039/D3CP02883F
SN - 1463-9076
VL - 25
IS - 35
SP - 23637
EP - 23644
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-58807
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Manoharan, Deepak
A1 - Ahmad, Shamim
A1 - Tothadi, Srinu
A1 - Emmerling, Franziska
A1 - Bhattacharya, Biswajit
A1 - Ghosh, Soumyajit
T1 - Linker size dependent mechanical properties of di-imine based molecular crystals
JF - CrystEngComm
N2 - We have demonstrated the ability to modify the mechanical flexibility of molecular crystals by modulating the length of intervening linker moieties while keeping the terminal shape synthons the same.
KW - Mechanically flexible molecular crystals
KW - Mechanical properties
KW - Crystal Engineering
PY - 2023
DO - https://doi.org/10.1039/D3CE00928A
SN - 1466-8033
SP - 1
EP - 8
PB - RSC
CY - London
AN - OPUS4-58836
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Cakir, Cafer Tufan
A1 - Piotrowiak, T.
A1 - Reinholz, Uwe
A1 - Ludwig, A.
A1 - Emmerling, Franziska
A1 - Streli, C.
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Radtke, Martin
T1 - Exploring the Depths of Corrosion: A Novel GE-XANES Technique for Investigating Compositionally Complex Alloys
JF - Analytical Chemistry
N2 - In this study, we propose the use of nondestructive, depth-resolved, element-specific characterization using grazing exit X-ray absorption near-edge structure spectroscopy (GE-XANES) to investigate the corrosion process in compositionally complex alloys (CCAs). By combining grazing exit X-ray fluorescence spectroscopy (GE-XRF) geometry and a pnCCD detector, we provide a scanning-free, nondestructive, depth-resolved analysis in a sub-micrometer depth range, which is especially relevant for layered materials, such as corroded CCAs. Our setup allows for spatial and energy-resolved measurements and directly extracts the desired fluorescence line, free from scattering events and other overlapping lines. We demonstrate the potential of our approach on a compositionally complex CrCoNi alloy and a layered reference sample with known composition and specific layer thickness. Our findings indicate that this new GE-XANES approach has exciting opportunities for studying surface catalysis and corrosion processes in real-world materials.
KW - Degradation mechanisms
KW - Grazin exit XANES
KW - Depth resolved XANES
KW - Compositional complex alloys
KW - Corrosion
PY - 2023
DO - https://doi.org/10.1021/acs.analchem.3c00404
VL - 95
SP - 4810
EP - 4818
PB - ACS Publications
AN - OPUS4-57823
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Radtke, Martin
A1 - Yusenko, Kirill
A1 - Stawski, Tomasz
A1 - Kulow, Anicó
A1 - Cakir, Cafer Tufan
A1 - Röder, Bettina
A1 - Naese, Christoph
A1 - Britzke, Ralf
A1 - Sintschuk, Michael
A1 - Emmerling, Franziska
T1 - BAMline - A real-life sample materials research beamline
JF - The Journal of Chemical Physics
N2 - With increasing demand and environmental concerns, researchers are exploring new materials that can perform as well or better than traditional materials while reducing environmental impact. The BAMline, a real-life sample materials research beamline, provides unique insights into materials’ electronic and chemical structure at different time and length scales. The beamline specializes in x-ray absorption spectroscopy, x-ray fluorescence spectroscopy, and tomography experiments. This enables real-time optimization of material properties and performance for various applications, such as energy transfer, energy storage, catalysis, and corrosion resistance. This paper gives an overview of the analytical methods and sample environments of the BAMline, which cover non-destructive testing experiments in materials science, chemistry, biology, medicine, and cultural heritage. We also present our own synthesis methods, processes, and equipment developed specifically for the BAMline, and we give examples of synthesized materials and their potential applications. Finally, this article discusses the future perspectives of the BAMline and its potential for further advances in sustainable materials research.
KW - Extended X-ray absorption fine structure
KW - Energy storage
KW - Environmental impacts
KW - Nondestructive testing techniques
KW - X-ray fluorescence spectroscopy
KW - Corrosion
KW - Near edge X-ray absorption fine structure spectroscopy
KW - X-ray absorption spectroscopy
PY - 2023
DO - https://doi.org/10.1063/5.0157194
VL - 158
IS - 24
SP - 1
EP - 22
PB - AIP Publishing
AN - OPUS4-57824
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Manoharan, D.
A1 - Megha, S. N.
A1 - Kiran, M. S. R. N.
A1 - Emmerling, Franziska
A1 - Bhattacharya, Biswajit
A1 - Ghosh, S.
T1 - Designing the Mechanical Plasticity of Benzylidene Indanones Based Molecular Crystals by Crystal Engineering
JF - Crystal Growth & Design
N2 - Mechanically flexible molecular crystals have important implications in flexible optoelectronics, optical waveguides, etc. We report a series of 2-benzylidene 1-indanone based plastic crystals. Moreover, we have shown how plasticity can be fine-tuned through controlling intermolecular interactions.
KW - Mechanical flexibility
KW - Organic crystal
KW - Mechanical property
PY - 2023
DO - https://doi.org/10.1021/acs.cgd.2c01137
SN - 1528-7483
VL - 23
SP - 657
EP - 661
PB - ACS Publications
AN - OPUS4-57773
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rautenberg, Max
A1 - Akhmetova, Irina
A1 - Das, Chayanika
A1 - Bhattacharya, Biswajit
A1 - Emmerling, Franziska
T1 - Synthesis and In Situ Monitoring of Mechanochemical Preparation of Highly Proton Conductive Hydrogen-Bonded Metal Phosphonates
JF - ACS Omega
N2 - Crystalline porous materials are recognized as promising proton conductors for the proton exchange membrane (PEM) in fuel cell technology owing to their tunable framework structure. However, it is still a challenging bulk synthesis for real-world applications of these materials. Herein, we report the mechanochemical gram-scale synthesis of two isostructural metal hydrogen-bonded organic frameworks (MHOFs) of Co(II) and Ni(II) based on 1-hydroxyethylidenediphosphonic acid (HEDPH4) with 2,2′-bipyridine (2,2′-bipy): Co(HEDPH3)2(2,2′-bipy)·H2O (1) and Ni(HEDPH3)2(2,2′-bipy)·H2O (2). In situ monitoring of the mechanochemical synthesis using different synchrotron-based techniques revealed a one-step mechanism – the starting materials are directly converted to the product. With the existence of extensive hydrogen bonds with amphiprotic uncoordinated phosphonate hydroxyl and oxygen atoms, both frameworks exhibited proton conduction in the range of 10–4 S cm–1 at room temperature under humid conditions. This study demonstrates the potential of green mechanosynthesis for bulk material preparation of framework-based solid-state proton conductors.
KW - Mechanochemistry
KW - Proton conductivity
KW - Metal Organic Frameworks
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-577777
DO - https://doi.org/10.1021/acssuschemeng.2c07509
VL - 8
IS - 19
SP - 16687
EP - 16693
PB - ACS Publications
AN - OPUS4-57777
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Karafiludis, Stephanos
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Heinekamp, Christian
A1 - Smales, Glen Jacob
A1 - Hodoroaba, Vasile-Dan
A1 - ten Elshof, J. E.
A1 - Emmerling, Franziska
A1 - Stawski, Tomasz
T1 - Template-free synthesis of mesoporous, amorphous transition metal phosphate materials
JF - Nanoscale
N2 - We present how mesoporosity can be engineered in transition metal phosphate (TMPs) materials in a template-free manner. The method involves a transformation of a precursor metal phosphate phase, called M-struvite (NH4MPO4·6H2O, M = Mg2+, Ni2+, Co2+, NixCo1-x2+). It relies on the thermal decomposition of crystalline M-struvite precursors to an amorphous and simultaneously mesoporous phase, which forms while degassing of NH3 and H2O. The temporal evolution of mesoporous frameworks and the response of the metal coordination environment were followed with in-situ and ex-situ scattering and diffraction, as well as X -ray spectroscopy. Despite sharing the same precursor struvite structure, different amorphous and mesoporous structures were obtained depending on the involved transition metal. We highlight the systematic differences in absolute surface area, pore shape, pore size, and phase transitions depending on a metal cation present in the analogous M-struvites. The amorphous structures of thermally decomposed Mg-, Ni- and NixCo1-x-struvites exhibit high surface areas and pore volumes (240 m²g-1 and 0.32 cm-3 g-1 for Mg and 90 m²g-1 and 0.13 cm-3 g-1 for Ni). We propose that the low-cost, environmentally friendly M-struvites could be obtained as recycling products from industrial and agricultural wastewaters. These waste products could be then upcycled into mesoporous TMPs through a simple thermal treatment for further applications, for instance, in (electro)catalysis.
KW - Struvite
KW - Pphosphates
KW - Transition metal
KW - In-situ SAXS/WAXS
KW - Mesoporosity
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-569503
DO - https://doi.org/10.1039/D2NR05630E
SN - 2040-3364
SP - 1
EP - 15
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-56950
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Getenet, M.
A1 - Otálora, F.
A1 - Emmerling, Franziska
A1 - Al-Sabbagh, Dominik
A1 - García-Ruiz, J. M.
T1 - Mineral precipitation and hydrochemical evolution through evaporitic processes in soda brines (East African Rift Valley)
JF - Chemical geology
N2 - Soda lakes of the East African Rift Valley are hyperalkaline, hypersaline lakes extremely enriched in Na+, K+, Cl−, CO32−, HCO3−, and SiO2. In this paper, we investigate the chemical evolution in these lakes and the production of chemical sediments by salt precipitation via evaporation. Water samples from tributary springs and three lakes (Magadi, Nasikie Engida and Natron) have been experimentally studied by in-situ X-ray diffraction during evaporation experiments to characterize the sequence of mineral precipitation. These data are complemented by ex-situ diffraction studies, chemical analyses and thermodynamic hydrochemical calculations producing detailed information on the activity of all solution species and the saturation state of all minerals potentially generated by the given composition. Major minerals precipitating from these samples are sodium carbonates/bicarbonates as well as halite. The CO3/HCO3 ratio, controlled by pH, is the main factor defining the Na‑carbonates precipitation sequence: in lake brines where CO3/HCO3 > 1, trona precipitates first whereas in hot springs, where CO3/HCO3 ≪ 1, nahcolite precipitates instead of trona, which forms later via partial dissolution of nahcolite. Precipitation of nahcolite is possible only at lower pH values (pCO2 higher than −2.7) explaining the distribution of trona and nahcolite in current lakes and the stratigraphic sequences. Later, during evaporation, thermonatrite precipitates, normally at the same time as halite, at a very high pH (>11.2) after significant depletion of HCO3− due to trona precipitation. The precipitation of these soluble minerals increases the pH of the brine and is the main factor contributing to the hyperalkaline and hypersaline character of the lakes. Villiaumite, sylvite, alkaline earth carbonates, fluorapatite and silica are also predicted to precipitate, but most of them have not been observed in evaporation experiments, either because of the small amount of precipitates produced, kinetic effects delaying the nucleation of some phases, or by biologically induced effects in the lake chemistry that are not considered in our calculations. Even in these cases, the chemical composition in the corresponding ions allows for discussion on their accumulation and the eventual precipitation of these phases. The coupling of in-situ and ex-situ experiments and geochemical modelling is key to understanding the hydrogeochemical and hydroclimatic conditions of soda lakes, evaporite settings, and potentially soda oceans of early Earth and other extraterrestrial bodies.
KW - Crystallization sequence
KW - Hydrochemical evolution
KW - Alkaline brines
KW - Sodium carbonate minerals
KW - Soda lakes
KW - Evaporite deposits
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-568431
DO - https://doi.org/10.1016/j.chemgeo.2022.121222
SN - 0009-2541
VL - 616
SP - 1
EP - 13
PB - Elsevier
CY - New York, NY
AN - OPUS4-56843
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Karafiludis, Stephanos
A1 - Ryll, T. W.
A1 - Buzanich, Ana Guilherme
A1 - Emmerling, Franziska
A1 - Stawski, Tomasz Maciej
T1 - Phase stability studies on transition metal phosphates aided by an automated synthesis
JF - Royal Society of Chemistry (RSC)
N2 - Transition metal phosphates (TMPs) have attracted interest as materials for (electro-) catalysis, and electrochemistry due to their low-cost, stability, and tunability. In this work, an automated synthesis platform was used for the preparation of transition metal phosphate crystals to efficiently explore the multidimensional parameter space, determining the phase selection, crystal sizes, shapes. By using X-ray diffraction and spectroscopy-based methods and electron microscopy imaging, a complete characterization of the phase stability fields, phase transitions, and crystal morphology/sizes was achieved. In an automated three-reactant synthesis, the individual effect of each reactant species NH4+, M2+, and PO43- on the formation of transition metal phosphate phases: M-struvite NH4MPO4·6H2O, M-phosphate octahydrate M3(PO4)2·8H2O with M = Ni, Co and an amorphous phase, was investigated. The NH4+ concentration dictates the phase composition, morphology, and particle size in the Ni-system (crystalline Ni-struvite versus amorphous Ni-PO4 phase), whereas in the Co-system all reactant species - NH4+, Co2+, and PO43- - influence the reaction outcome equivalently (Co-struvite vs. Co-phosphate octahydrate). The coordination environment for all crystalline compounds and of the amorphous Ni-PO4 phase was resolved by X-ray absorption spectroscopy, revealing matching characteristics to its crystalline analogue, Ni3(PO4)2·8H2O. The automated synthesis turned out to be significantly advantageous for the exploration of phase diagrams due to its simple modularity, facile traceability, and enhanced reproducibility compared to a typical manual synthesis.
KW - Automated synthesis
KW - Phase diagrams
KW - Transition metals
KW - Phosphates
KW - Local structure
KW - Struvite
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-579151
DO - https://doi.org/10.1039/D3CE00386H
VL - 25
IS - 30
SP - 4333
EP - 4344
PB - CrystEngComm
CY - London
AN - OPUS4-57915
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Somasundaram, S. K.
A1 - Buzanich, Ana
A1 - Emmerling, Franziska
A1 - Krishnan, S.
A1 - Senthilkumar, K.
A1 - Joseyphus, R.J.
T1 - New insights into pertinent Fe-complexes for the synthesis of iron via the instant polyol process
JF - Physical Chemistry Chemical Physics
N2 - Chemically synthesized iron is in demand for biomedical applications due to its large saturation magnetization compared to iron oxides. The polyol process, suitable for obtaining Co and Ni particles and their alloys, is laborious in synthesizing Fe. The reaction yields iron oxides, and the reaction pathway remains unexplored. This study shows that a vicinal polyol, such as 1,2-propanediol, is suitable for obtaining Fe rather than 1,3-propanediol owing to the formation of a reducible Fe intermediate complex. X-ray absorption spectroscopy analysis reveals the ferric octahedral geometry and tetrahedral geometry in the ferrous state of the reaction intermediates in 1,2-propanediol and 1,3-propanediol, respectively. The final product obtained using a vicinal polyol is Fe with a γ-Fe2O3 shell, while the terminal polyol is favourable for Fe3O4. The distinct Fe–Fe and Fe–O bond lengths suggest the presence of a carboxylate group and a terminal alkoxide ligand in the intermediate of 1,2-propanediol. A large Fe–Fe bond distance suggests diiron complexes with bidentate carboxylate bridges. Prominent high-spin and low-spin states indicate the possibility of transition, which favors the reduction of iron ions in the reaction using 1,2-propanediol.
KW - XAS
KW - Nanoparticle
PY - 2023
DO - https://doi.org/10.1039/D3CP01969A
SN - 1463-9076
VL - 25
IS - 33
SP - 21970
EP - 21980
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-58073
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Fink, Friedrich
A1 - Stawski, Tomasz M.
A1 - Stockmann, Jörg M.
A1 - Emmerling, Franziska
A1 - Falkenhagen, Jana
T1 - Surface Modification of Kraft Lignin by Mechanochemical Processing with Sodium Percarbonate
JF - Biomacromolecules
N2 - In this article, we present a novel one-pot mechanochemical reaction for the surface activation of lignin.
The process involves environmentally friendly oxidation with hydrogen peroxide, depolymerization of fractions with high molecular mass, and introduction of new carbonyl functions into the lignin backbone. Kraft lignin was ground with sodium percarbonate and sodium hydroxide in a ball mill at different time intervals. Analyses by infrared spectroscopy (IR), nuclear magnetic resonance spectroscopy (NMR), size exclusion chromatography (SEC), dynamic vapor sorption (DVS), and small-angle X-ray scattering (SAXS) showed significant improvements. After only 5 min of reaction, there was a 47% reduction in mass-average molecular weight and an increase in carboxyl functionalities.
Chemical activation resulted in an approximately 2.8-fold increase in water adsorption. Principal component analysis (PCA) provided further insight into the correlations between IR spectra and SAXS parameters
KW - Kraft Lignin
KW - Mechanochemical oxidation
KW - SEC
KW - FTIR
KW - SAXS
KW - PCA
PY - 2023
DO - https://doi.org/10.1021/acs.biomac.3c00584
SN - 1525-7797
SP - 1
EP - 11
PB - American Chemical Society
AN - OPUS4-58074
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Manoharan, D.
A1 - Ahmad, S.
A1 - Emmerling, Franziska
A1 - Bhattacharya, Biswajit
A1 - Ghosh, S.
T1 - Stress and light sensitive dual-mechanical property of acylhydrazone crystal
JF - CrystEngComm
N2 - Mechanically dual-responsive molecular crystals have gained ubstantial interest among researchers due to their significant applications in various fields. However, incorporation of disparate mechanical responses in the same crystalline material is still a challenging issue and is continuously being explored. Here, we report long acicular crystals derived from 4-bromobenzhydrazide and 9-anthraldehyde exhibit both stressinduced mechanical bending and blue-light induced photomechanical bending. Furthermore, the crystals show thermal back isomerization upon gradual heating. These two distinct mechanical responses in the crystalline phase have been studied and their structure–property correlation have been established.
KW - Light sensitive crystal
KW - Mechanical flexibility
KW - Organic crystal
PY - 2023
DO - https://doi.org/10.1039/d3ce00296a
VL - 25
IS - 21
SP - 3237
EP - 3244
PB - Royal Society of Chemisty (RSC)
CY - London/Cambridge
AN - OPUS4-57593
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Peters, Stefan
A1 - Kunkel, Benny
A1 - Cakir, Cafer Tufan
A1 - Kabelitz, Anke
A1 - Witte, Steffen
A1 - Bernstein, Thomas
A1 - Bartling, Stephan
A1 - Radtke, Martin
A1 - Emmerling, Franziska
A1 - Abdel-Mageed, Ali Mohamed
A1 - Wohlrab, Sebastian
A1 - Guilherme Buzanich, Ana
T1 - Time-, space- and energy-resolved in situ characterization of catalysts by X-ray absorption spectroscopy
JF - Chemical Communications
N2 - A novel setup for dispersive X-ray absorption spectroscopy (XAS) with simultaneous resolution of space, time and energy for in situ characterization of solid materials is demonstrated.
KW - Dispersive XAS
KW - Catalysis
KW - In situ
KW - Structure analysis
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-584924
DO - https://doi.org/10.1039/d3cc03277a
SN - 1359-7345
SP - 1
EP - 4
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-58492
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Karafiludis, Stephanos
A1 - Scoppola, E.
A1 - Wolf, S.E.
A1 - Kochovski, Z.
A1 - Matzdorff, D.
A1 - Van Driessche, A. E. S.
A1 - Hövelmann, J.
A1 - Emmerling, Franziska
A1 - Stawski, Tomasz M.
T1 - Evidence for liquid-liquid phase separation during the early stages of Mg-struvite formation
JF - The Journal of Chemical Physics
N2 - The precipitation of struvite, a magnesium ammonium phosphate hexahydrate (MgNH₄PO₄ · 6H₂O) mineral, from wastewater is a promising method for recovering phosphorous. While this process is commonly used in engineered environments, our understanding of the underlying mechanisms responsible for the formation of struvite crystals remains limited. Specifically, indirect evidence suggests the involvement of an amorphous precursor and the occurrence of multi-step processes in struvite formation, which would indicate non-classical paths of nucleation and crystallization. In this study, we use synchrotron-based in situ x-ray scattering complemented by cryogenic transmission electron microscopy to obtain new insights from the earliest stages of struvite formation. The holistic scattering data captured the structure of an entire assembly in a time-resolved manner. The structural features comprise the aqueous medium, the growing struvite crystals, and any potential heterogeneities or complex entities. By analysing the scattering data, we found that the onset of crystallization causes a perturbation in the structure of the surrounding aqueous medium. This perturbation is characterized by the occurrence and evolution of Ornstein-Zernike fluctuations on a scale of about 1 nm, suggesting a non-classical nature of the system. We interpret this phenomenon as a liquid-liquid phase separation, which gives rise to the formation of the amorphous precursor phase preceding actual crystal growth of struvite. Our microscopy results confirm that the formation of Mg-struvite includes a short-lived amorphous phase, lasting >10 s.
KW - Physical and theoretical chemistry
KW - Non-classical crystallization
KW - Struvite
KW - Liquid-liquid-phase-separation
KW - Nucleation
KW - Crystallization
KW - In-situ scattering
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-584766
DO - https://doi.org/10.1063/5.0166278
SN - 1089-7690
VL - 159
IS - 13
SP - 1
EP - 12
PB - AIP Publishing
CY - Woodbury, NY
AN - OPUS4-58476
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bernardes, C. E. S.
A1 - Feliciano, I.O.
A1 - Naese, Christoph
A1 - Emmerling, Franziska
A1 - Minas da Piedade, M.
T1 - Energetics of dehydroepiandrosterone polymorphs I and II from solution and drop-sublimation Calvet microcalorimetry measurements
JF - The Journal of Chemical Thermodynamics
N2 - The lattice enthalpies and monotropic relationship of two dehydroepiandrosterone (DEHA) polymorphs (forms I and II) were evaluated through a combination of differential scanning calorimetry (DSC), isothermal solution microcalorimetry, and drop-sublimation Calvet microcalorimetry experiments. The standard molar enthalpy of transition between both forms was determined as ΔtrsHom (II→I, 298.15 K) = - 0.90 ± 0.07 kJ mol-1 and ΔtrsHom (II→I, 417.8 K) = - 1.7 ± 1.0 kJ mol- 1, from measurements of standard molar enthalpies of solution in dimethyl sulfoxide and enthalpies of fusion, respectively. Drop-sublimation Calvet microcalorimetry experiments on form I led to ΔsubHom (cr I, 298.15 K) = 132.0±3.3 kJ mol - 1. This result, when combined with the more precise ΔtrsHom (II→I) value obtained by solution calorimetry, afforded ΔsubHom (cr II, 298.15 K) = 131.1±3.3 kJ mol - 1. The overall data indicate that on enthalpic grounds form I is more stable than form II from 298.15 K up to fusion. This conclusion, and the fact that DSC experiments indicated that form I has also a considerably higher temperature fusion, namely, Tfus(cr I)= 422.5±0.2 K and Tfus(cr II) = 413.1±0.2 K, suggest that the two polymorphs are monotropically related.
KW - Calorimetry
KW - Polymorphism
KW - Enthalpy of solution
KW - Enthalpy of sublimation
KW - Thermochemistry
KW - Lattice enthalpy
PY - 2023
DO - https://doi.org/10.1016/j.jct.2023.107137
SN - 0021-9614
SN - 1096-3626
VL - 186
SP - 1
EP - 7
PB - Elsevier
AN - OPUS4-58418
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Linberg, Kevin
A1 - Szymoniak, Paulina
A1 - Schönhals, Andreas
A1 - Emmerling, Franziska
A1 - Michalchuk, Adam A. L.
T1 - The Origin of Delayed Polymorphism in Molecular Crystals Under Mechanochemical Conditions
JF - Chemistry – A European Journal
N2 - We show that mechanochemically driven polymorphic transformations can require extremely long induction periods, which can be tuned from hours to days by changing ball milling energy. The robust design and interpretation of ball milling experiments must account for this unexpected kinetics that arises from energetic phenomena unique to the solid state. Detailed thermal analysis, combined with DFT simulations, indicates that these marked induction periods are associated with processes of mechanical activation. Correspondingly, we show that the pre‐activation of reagents can also lead to marked changes in the length of induction periods. Our findings demonstrate a new dimension for exerting control over polymorphic transformations in organic crystals. We expect mechanical activation to have a much broader implication across organic solid‐state mechanochemistry.
KW - General Chemistry
KW - Catalysis
KW - Organic Chemistry
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-589219
DO - https://doi.org/10.1002/chem.202302150
SN - 0947-6539
SP - e202302150
PB - Wiley
AN - OPUS4-58921
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Edzards, Joshua
A1 - Saßnick, Holger-Dietrich
A1 - Buzanich, Ana Guilherme
A1 - Valencia, Ana M.
A1 - Emmerling, Franziska
A1 - Beyer, Sebastian
A1 - Cocchi, Caterina
T1 - Effects of Ligand Substituents on the Character of Zn-Coordination in Zeolitic Imidazolate Frameworks
JF - The Journal of Physical Chemistry C
N2 - Due to their favorable properties and high porosity, zeolitic imidazolate frameworks (ZIFs) have recently received much limelight for key technologies such as energy storage, optoelectronics, sensorics, and catalysis. Despite widespread interest in these materials, fundamental questions regarding the zinc coordination environment remain poorly understood. By focusing on zinc(II)2-methylimidazolate (ZIF-8) and its tetrahedrally coordinated analogues with Br-, Cl-, and H-substitution in the 2-ring position, we aim to clarify how variations in the local environment of Zn impact the charge distribution and the electronic properties of these materials. Our results from densityfunctional theory confirm the presence of a Zn coordinative bond with a large polarization that is quantitatively affected by different substituents on the organic ligand. Moreover, our findings suggest that the variations in the Zn coordination induced by the functionalization have a negligible effect on the electronic structure of the considered compounds. On the other hand, halogen terminations of the ligands lead to distinct electronic contributions in the vicinity of the frontier region which ultimately reduce the band gap size by a few hundred millielectron volts. Experimental results obtained from X-ray absorption spectroscopy (Zn K-edge) confirm the trends predicted by theory and, together with them, contribute to a better understanding of the structure−property relationships that are needed to tailor ZIFs for target applications.
KW - Surfaces
KW - Physical and Theoretical Chemistry
KW - General Energy
KW - Electronic
KW - Coatings and Films
KW - Optical and Magnetic Materials
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-589117
DO - https://doi.org/10.1021/acs.jpcc.3c06054
SN - 1932-7447
VL - 127
IS - 43
SP - 21456
EP - 21464
PB - American Chemical Society (ACS)
AN - OPUS4-58911
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Emmerling, Franziska
A1 - Chewle, S.
A1 - Weber, M.
T1 - Revealing Kinetics of Paracetamol Crystallization Using Time Resolved Raman Spectroscopy, Orthogonal Time-Lapse Photography, and Non-Negative Matrix Factorization (OSANO)
JF - Crystal Growth & Design
N2 - Crystallization is a complex phenomenon with farreaching implications for the production and formulation of active pharmaceutical ingredients. Understanding this process is critical for achieving control over key physicochemical properties that can affect, for example, the bioavailability and stability of a drug. In this study, we were able to reveal intricate and diverse dynamics of the formation of metastable intermediates of paracetamol crystallization varying with the choice of solvent. We demonstrate the efficacy of our novel approach utilizing an objective function-based non-negative matrix factorization technique for the analysis of time-resolved Raman
spectroscopy data, in conjunction with time-lapse photography.
Furthermore, we emphasize the crucial importance of integrating Raman spectroscopy with supplementary experimental instrumentation for the mathematical analysis of the obtained spectra.
KW - Polymorphism
KW - Crystallization
KW - Measurement
KW - Algorithm
PY - 2023
DO - https://doi.org/10.1021/acs.cgd.3c00617
SN - 1528-7483
VL - 23
SP - 6737
EP - 6746
PB - ACS Publications
AN - OPUS4-58193
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Feiler, Torvid
A1 - Yasuda, N.
A1 - Michalchuk, Adam
A1 - Emmerling, Franziska
A1 - Bhattacharya, Biswajit
T1 - Mechanistic Investigation of an Elastically Flexible Organic Crystal
JF - Crystal Growth & Design
N2 - Mechanical flexibility in molecular crystals is a fascinating behavior with potential for developing advanced technologies. However, the phenomenon of mechanical bending is poorly understood. We explore for the first time the atomistic origin of elastic bending in a single component organic crystal using a combination of μ-focus synchrotron X-ray diffraction and ab initio simulation.
KW - Flexible crystals
KW - DFT calculation
KW - Bending mechanism
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-581949
DO - https://doi.org/10.1021/acs.cgd.3c00473
SN - 1528-7483
VL - 23
IS - 9
SP - 6244
EP - 6249
PB - ACS Publications
AN - OPUS4-58194
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Heinekamp, Christian
A1 - Guilherme Buzanich, Ana
A1 - Ahrens, M.
A1 - Braun, T.
A1 - Emmerling, Franziska
T1 - An amorphous Lewis-acidic zirconium chlorofluoride as HF shuttle: C–F bond activation and formation
JF - Chemical Communications
N2 - An exceptional HF transfer reaction by C–F bond activation of fluoropentane and a subsequent hydrofluorination of alkynes at room temperature is reported. An amorphous Lewis-acidic Zr chlorofluoride serves as heterogeneous catalyst, which is characterised by an eightfold coordination environment at Zr including chlorine atoms. The studies are seminal in establishing sustainable fluorine chemistry.
KW - ZCF
KW - Heterogeneous catalysis
KW - C-F bond activation
KW - HF-shuttle
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-582249
DO - https://doi.org/10.1039/D3CC03164K
SN - 1359-7345
VL - 59
IS - 75
SP - 11224
EP - 11227
PB - RSC
CY - Cambridge
AN - OPUS4-58224
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bui, M.
A1 - Hoffmann, K. F.
A1 - Braun, T.
A1 - Riedel, S.
A1 - Heinekamp, Christian
A1 - Scheurell, K.
A1 - Scholz, G.
A1 - Stawski, Tomasz
A1 - Emmerling, Franziska
T1 - An Amorphous Teflate Doped Aluminium Chlorofluoride:
A Solid Lewis-Superacid for the Dehydrofluorination of
Fluoroalkanes
JF - ChemCatChem
N2 - Ananion-dopedaluminiumchlorofluoride AlCl0.1F2.8(OTeF5)0.1(ACF-teflate) was synthesized.The material contains pentafluor-oorthotellurate(teflate)groups, which mimic fluoride ions electronically, but are sterically more demanding. They are embedded into the amorphous structure. The latter was studied by PDF analysis, EXAFS data and MAS NMR spectroscopy. The mesoporous powder is a Lewis superacid, and ATR-IR spectra of adsorbed CD3CN reveal a blue-shift of the adsorption band by73 cm-1, which is larger than the shift for SbF5. Remarkably,ACF-teflate catalyzes dehydrofluorination reactions of mono-fluoroalkanes to yield olefins in C6D6. In these cases,no Friedel-Crafts products were formed.
KW - Aluminium fluorides
KW - Aluminium teflates
KW - C-F bond activation
KW - Lewis superacids
KW - Silanes
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-572290
DO - https://doi.org/10.1002/cctc.202300350
SN - 1867-3880
SP - 1
EP - 7
PB - Wiley VHC-Verlag
AN - OPUS4-57229
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Gugin, Nikita
A1 - Villajos Collado, José Antonio
A1 - Dautain, O.
A1 - Maiwald, Michael
A1 - Emmerling, Franziska
T1 - Optimizing the Green Synthesis of ZIF-8 by Reactive Extrusion Using In Situ Raman Spectroscopy
JF - ACS Sustainable Chemistry & Engineering
N2 - We report the scale-up of a batch solid synthesis of zeolitic imidazolate framework-8 (ZIF-8) for reactive extrusion. The crystalline product forms in the extruder directly under the mixture of solid 2-methylimidazole and basic zinc carbonate in the presence of a catalytic amount of liquid. The process parameters such as temperature, liquid type, feeding rate, and linker excess were optimized using the setup specifically designed for in situ Raman spectroscopy. Highly crystalline ZIF-8 with a Brunauer–Emmett–Teller (BET) surface area of 1816 m2 g–1 was quantitatively prepared at mild temperature using a catalytic amount of ethanol and a small excess of the linker. Finally, we developed a simple and comprehensive approach to evaluating the environmental friendliness and scalability of metal–organic framework (MOF) syntheses in view of their large-scale production.
KW - Mechanochemistry
KW - In situ Raman
KW - Large-scale processing
KW - Metal−organic frameworks
KW - Twin-screw extrusion (TSE)
PY - 2023
DO - https://doi.org/10.1021/acssuschemeng.2c07509
SN - 2168-0485
VL - 11
IS - 13
SP - 5175
EP - 5183
PB - ACS Publications
AN - OPUS4-57366
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Karafiludis, Stephanos
A1 - Kochovski, Z.
A1 - Scoppola, E.
A1 - Retzmann, Anika
A1 - Hodoroaba, Vasile-Dan
A1 - ten Elshof, J. E.
A1 - Emmerling, Franziska
A1 - Stawski, Tomasz Maciej
T1 - Nonclassical Crystallization Pathway of Transition Metal Phosphate Compounds
JF - Chemistry of Materials
N2 - Here, we elucidate nonclassical multistep crystallization pathways of transition metal phosphates from aqueous solutions. We followed precipitation processes of M-struvites, NH4MPO4·6H2O, and M-phosphate octahydrates, M3(PO4)2·8H2O, where M = Ni, Co, or NixCo1–x, by using in situ scattering and spectroscopy-based techniques, supported by elemental mass spectrometry analyses and advanced electron microscopy. Ni and Co phosphates crystallize via intermediate colloidal amorphous nanophases, which change their complex structures while agglomerating, condensing, and densifying throughout the extended reaction times. We reconstructed the three-dimensional morphology of these precursors by employing cryo-electron tomography (cryo-ET). We found that the complex interplay between metastable amorphous colloids and protocrystalline units determines the reaction pathways. Ultimately, the same crystalline structure, such as struvite, is formed. However, the multistep process stages vary in complexity and can last from a few minutes to several hours depending on the selected transition metal(s), their concentration, and the Ni/Co ratio.
KW - Non-classical crystallization theory
KW - Transition metals
KW - Phosphates
KW - Amorphous phases
KW - Intermediate phases
PY - 2023
DO - https://doi.org/10.1021/acs.chemmater.3c02346
SN - 1520-5002
VL - 35
IS - 24
SP - 10645
EP - 10657
PB - American Chemical Society (ACS)
CY - Washington D.C.
AN - OPUS4-59135
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bhattacharya, Biswajit
A1 - Michalchuk, Adam A. L.
A1 - Silbernagl, Dorothee
A1 - Yasuda, N.
A1 - Feiler, Torvid
A1 - Sturm, Heinz
A1 - Emmerling, Franziska
T1 - An atomistic mechanism for elasto-plastic bending in molecular crystals
JF - Chemical Science
N2 - Mechanically flexible single crystals of molecular materials offer potential for a multitude of new directions in advanced materials design. Before the full potential of such materials can be exploited, insight into their mechanisms of action must be better understood. Such insight can be only obtained through synergistic use of advanced experimentation and simulation. We herein report the first detailed mechanistic study of elasto-plastic flexibility in a molecular solid. An atomistic origin for this mechanical behaviour is proposed through a combination of atomic force microscopy, μ-focus synchrotron X-ray diffraction, Raman spectroscopy, ab initio simulation, and computed elastic tensors. Our findings suggest that elastic and plastic bending are intimately linked and result from extensions of the same molecular deformations. The proposed mechanism bridges the gap between contested mechanisms, suggesting its applicability as a general mechanism for elastic and plastic bending in organic molecular crystals.
KW - Mechanical property
KW - Mechanical flexibility
KW - Organic crystal
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-577722
DO - https://doi.org/10.1039/D2SC06470G
SN - 2041-6520
VL - 14
IS - 13
SP - 3441
EP - 3450
PB - Royal Society of Chemisty (RSC)
CY - London/Cambridge
AN - OPUS4-57772
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Chinnasamy, R.
A1 - Ravi, J.
A1 - Pradeep, V.V.
A1 - Manoharan, D.
A1 - Emmerling, Franziska
A1 - Bhattacharya, Biswajit
A1 - Ghosh, S.
T1 - Adaptable Optical Microwaveguides From Mechanically Flexible Crystalline Materials
JF - Chemistry-A European Journal
N2 - Flexible organic crystals (elastic and plastic) are important materials for optical waveguides, tunable optoelectronic devices, and photonic integrated circuits. Here, we present highly elastic organic crystals of a Schiff base, 1-((E)-(2,5-dichlorophenylimino)methyl)naphthalen-2-ol (1), and an azine molecule, 2,4-dibromo-6-((E)-((E)-(2,6-dichlorobenzylidene)hydrazono)methyl)phenol (2). These microcrystals are highly flexible under external mechanical force, both in the macroscopic and the microscopic regimes. The mechanical flexibility of these crystals arises as a result of weak and dispersive C−H⋅⋅⋅Cl, Cl⋅⋅⋅Cl, Br⋅⋅⋅Br, and π⋅⋅⋅π stacking interactions. Singly and doubly-bent geometries were achieved from their straight shape by a micromechanical approach using the AFM cantilever tip. Crystals of molecules 1 and 2 display a bright-green and red fluorescence (FL), respectively, and selective reabsorption of a part of their FL band. Crystals 1 and 2 exhibit optical-path-dependent low loss emissions at the termini of crystal in their straight and even in extremely bent geometries. Interestingly, the excitation position-dependent optical modes appear in both linear and bent waveguides of crystals 1 and 2, confirming their light-trapping ability.
KW - Crystal growth
KW - Fluorescence
KW - Mechanophotonics
KW - Micromanipulation
KW - Optical waveguides
PY - 2022
DO - https://doi.org/10.1002/chem.202200905
SN - 0947-6539
SP - 1
EP - 8
PB - Wiley VHC-Verlag
AN - OPUS4-55018
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Belenguer, A.
A1 - Lampronti, G.
A1 - Michalchuk, Adam
A1 - Emmerling, Franziska
A1 - Sanders, J.
T1 - Quantitative reversible one pot interconversion of three crystalline polymorphs by ball mill grinding
JF - Crystengcomm
N2 - We demonstrate here using a disulfide system the first example of reversible, selective, and quantitative transformation between three crystalline polymorphs by ball mill grinding. This includes the discovery of a previously unknown polymorph. Each polymorph is reproducibly obtained under well-defined neat or liquid-assisted grinding conditions, revealing subtle control over the apparent thermodynamic stability. We discovered that the presence of a contaminant as low as 1.5% mol mol−1 acting as a template is required to enable all these three polymorph transformations. The relative stabilities of the polymorphs are determined by the sizes of the nanocrystals produced under different conditions and by surface interactions with small amounts of added solvent. For the first time, we show evidence that each of the three polymorphs is obtained with a unique and reproducible crystalline size. This mechanochemical approach gives access to bulk quantities of metastable polymorphs that are inaccessible through recrystallisation.
KW - Mechanochemistry
KW - Polymorph
KW - XRD
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-549934
DO - https://doi.org/10.1039/D2CE00393G
SP - 1
EP - 7
PB - Royal Society of Chemistry
AN - OPUS4-54993
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Karafiludis, Stephanos
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Kochovski, Z.
A1 - Feldmann, Ines
A1 - Emmerling, Franziska
A1 - Stawski, Tomasz
T1 - Ni- and Co-Struvites: Revealing Crystallization Mechanisms and Crystal Engineering toward Applicational Use of Transition Metal Phosphates
JF - Crystal Growth & Design
N2 - Industrial and agricultural waste streams (waste water, sludges, tailings, etc.) which contain high concentrations of NH4+, PO43–, and transition metals are environmentally harmful and toxic pollutants. At the same time, phosphorous and transition metals constitute highly valuable resources. Typically, separate pathways have been considered to extract hazardous transition metals or phosphate independently from each other. Investigations on the simultaneous removal of multiple components have been carried out only to a limited extent. Here, we report the synthesis routes for Ni- and Co-struvites (NH4MPO4·6H2O, M = Ni2+ and Co2+), which allow for P, ammonia, and metal co-precipitation. By evaluating different reaction parameters, the phase and stability of transition metal struvites as well as their crystal morphologies and sizes could be optimized. Ni-struvite is stable in a wide reactant concentration range and at different metal/phosphorus (M/P) ratios, whereas Co-struvite only forms at low M/P ratios. Detailed investigations of the precipitation process using ex situ and in situ techniques provided insights into the crystallization mechanisms/crystal engineering of these materials. M-struvites crystallize via intermediate colloidal amorphous nanophases, which subsequently aggregate and condense to final crystals after extended reaction times. However, the exact reaction kinetics of the formation of a final crystalline product varies significantly depending on the involved metal cation in the precipitation process: several seconds (Mg) to minutes (Ni) to hours (Co). The achieved level of control over the morphology and size makes precipitation of transition metal struvites a promising method for direct metal recovery and binding them in the form of valuable phosphate raw materials. Under this paradigm, the crystals can be potentially up-cycled as precursor powders for electrochemical or (electro)catalytic applications, which require transition metal phosphates.
KW - Crystallization
KW - Struvite
KW - Nickel
KW - Cobalt
KW - Phosphorous recovery
KW - Up-cycling
KW - Aqueous synthesis
PY - 2022
DO - https://doi.org/10.1021/acs.cgd.2c00284
VL - 22
IS - 7
SP - 4305
EP - 4315
PB - ACS Publications
CY - Washington D.C.
AN - OPUS4-55286
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Accorsi, M.
A1 - Tiemann, M.
A1 - Wehrhan, L.
A1 - Finn, Lauren M.
A1 - Cruz, R.
A1 - Rautenberg, Max
A1 - Emmerling, Franziska
A1 - Heberle, J.
A1 - Keller, B. G.
A1 - Rademann, J.
T1 - Pentafluorophosphato-Phenylalanines: Amphiphilic Phosphotyrosine Mimetics Displaying Fluorine-Specific Protein Interactions
JF - Angewandte Chemie International Edition
N2 - Phosphotyrosine residues are essential functional switches in health and disease. Thus, phosphotyrosine biomimetics are crucial for the development of chemical tools and drug molecules. We report here the discovery and investigation of pentafluorophosphato amino acids as novel phosphotyrosine biomimetics. A mild acidic pentafluorination protocol was developed and two PF5-amino acids were prepared and employed in peptide synthesis. Their structures, reactivities, and fluorine-specific interactions were studied by NMR and IR spectroscopy, X-ray diffraction, and in bioactivity assays. The mono-anionic PF5 motif displayed an amphiphilic character binding to hydrophobic surfaces, to water molecules, and to protein-binding sites, exploiting charge and H−F-bonding interactions. The novel motifs bind 25- to 30-fold stronger to the phosphotyrosine binding site of the protein tyrosine phosphatase PTP1B than the best current biomimetics, as rationalized by computational methods, including molecular dynamics simulations.
KW - Chemical Biology
KW - Drug Development
KW - Pentafluorophosphates
KW - Phosphotyrosine Biomimetics
KW - Protein Tyrosine Phosphatases
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-549984
DO - https://doi.org/10.1002/anie.202203579
SN - 1433-7851
VL - 134
IS - 25
SP - 1
EP - 6
PB - Wiley-VCH GmbH
AN - OPUS4-54998
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Loges, A.
A1 - Scholz, G.
A1 - Amadeu de Sosa, Nader
A1 - Jingjing, S.
A1 - Emmerling, Franziska
A1 - John, T.
A1 - Paulus, B.
A1 - Braun, T.
T1 - Studies on the local structure of the F/OH site in topaz by magic angle spinning nuclear magnetic resonance and Raman spectroscopy
JF - European journal of mineralogy
N2 - he mutual influence of F and OH groups in neighboring sites in topaz (Al2SiO4(F,OH)2) was investigated using magic angle spinning nuclear magnetic resonance (MAS NMR) and Raman spectroscopy. The splitting of 19F and 1H NMR signals, as well as the OH Raman band, provides evidence for hydrogen bond formation within the crystal structure. Depending on whether a given OH group has another OH group or fluoride as its neighbor, two different hydrogen bond constellations may form: either OH···O···HO or F···H···O. The proton accepting oxygen was determined to be part of the SiO4 tetrahedron using 29Si MAS NMR. Comparison of the MAS NMR data between an OH-bearing and an OH-free topaz sample confirms that the 19F signal at −130 ppm stems from F− ions that take part in H···F bonds with a distance of ∼ 2.4 Å, whereas the main signal at −135 ppm belongs to fluoride ions with no immediate OH group neighbors. The Raman OH sub-band at 3644 cm−1 stems from OH groups neighboring other OH groups, whereas the sub-band at 3650 cm−1 stems from OH groups with fluoride neighbors, which are affected by H···F bridging. The integrated intensities of these two sub-bands do not conform to the expected ratios based on probabilistic calculations from the total OH concentration. This can be explained by a difference in the polarizability of the OH bond between the different hydrogen bond constellations or partial order or unmixing of F and OH, or a combination of both. This has implications for the quantitative interpretation of Raman data on OH bonds in general and their potential use as a probe for structural (dis-)order. No indication of tetrahedrally coordinated Al was found with 27Al MAS NMR, suggesting that the investigated samples likely have nearly ideal Al/Si ratios, making them potentially useful as high-density electron microprobe reference materials for Al and Si, as well as for F.
KW - Topas
KW - NMR
KW - XRD
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-561863
DO - https://doi.org/10.5194/ejm-34-507-2022
SN - 1617-4011
VL - 34
IS - 5
SP - 507
EP - 521
PB - Copernicus Publications
CY - Göttingen
AN - OPUS4-56186
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Emmerling, Franziska
A1 - Hoch, C.
T1 - Laudatio Prof. Dr.-Ing. Caroline Röhr
JF - Zeitschrift für anorganische und allgemeine Chemie
N2 - It is a laudatio on the ocations of Prof. Dr.-Ing. Caroline Röhrs 60th birthday.
KW - Metal-oxides
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-561877
DO - https://doi.org/10.1002/zaac.202200159
SN - 0044-2313
VL - 648
IS - 10
SP - 1
EP - 2
PB - John Wiley & Sons, Ltd
AN - OPUS4-56187
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zänker, Steffen
A1 - Scholz, G.
A1 - Marquardt, Julien
A1 - Emmerling, Franziska
T1 - Structural changes in Ba-compounds of different hardness induced by high-energy ball milling – evidenced by 137Ba NMR and X-ray powder diffraction
JF - Zeitschrift für anorganische und allgemeine Chemie
N2 - Changes in the global bulk and local structures, of three different barium compounds (BaZrO3, BaF2, and BaFCl),were induced by mechanical milling and followed using X-ray powder diffraction (PXRD), subsequent microstructure analysis, and 137Ba solid state NMR spectroscopy. Harder materials like BaZrO3 experience significantly higher structural changes upon milling than softer materials like BaF2. Moreover, soft materials with layered structures, like BaFCl, show a pronounced structural change during the milling process. By combining PXRD and solid state NMR, detailed information on the changes to the global and local structures were obtained, which are of interest for mechanochemical synthesis, mechanically treated catalysts or ionic conductors.
KW - Mechanochemistry
KW - X-ray diffraction
KW - Solid state NMR
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-547397
DO - https://doi.org/10.1002/zaac.202200026
SN - 0044-2313
VL - 648
IS - 10
SP - 1
EP - 8
PB - Wiley-VCH
CY - Weinheim
AN - OPUS4-54739
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Mazzeo, P. P.
A1 - Prencipe, M.
A1 - Feiler, Torvid
A1 - Emmerling, Franziska
A1 - Bacchi, A.
T1 - On the mechanism of cocrystal mechanochemical reaction via low melting eutectic: A time-resolved in situ monitoring investigation
JF - Crystal growth and design
N2 - Mechanochemistry has become a sustainable and attractive cost-effective synthetic technique, largely used within the frame of crystal engineering. Cocrystals, namely, crystalline compounds made of different chemical entities within the same crystal structure, are typically synthesized in bulk via mechanochemistry; however, whereas the macroscopic aspects of grinding are becoming clear, the fundamental principles that underlie mechanochemical cocrystallization at the microscopic level remain poorly understood. Time-resolved in situ (TRIS) monitoring approaches have opened the door to exceptional detail regarding mechanochemical reactions. We here report a clear example of cocrystallization between two solid coformers that proceeds through the formation of a metastable low melting binary eutectic phase. The overall cocrystallization process has been monitored by time-resolved in situ (TRIS) synchrotron X-ray powder diffraction with a customized ball milling setup, currently available at μ Spot beamline at BESSY-II, Helmholtz-Zentrum Berlin. The binary system and the low melting eutectic phase were further characterized via DSC, HSM, and VT-XRPD.
KW - Mechanochemistry
KW - In situ
KW - Cocrystal
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-552977
DO - https://doi.org/10.1021/acs.cgd.2c00262
SN - 1528-7505
VL - 22
IS - 7
SP - 4260
EP - 4267
PB - ACS Publ.
CY - Washington, DC
AN - OPUS4-55297
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Lakshmipathi, M.
A1 - Dey, S.
A1 - Emmerling, Franziska
A1 - Bhattacharya, Biswajit
A1 - Michalchuk, Adam
T1 - Designing Dual Mechanical Response in Molecular Crystals through Cocrystallization
JF - Crystal Growth and Design
N2 - Two isomorphous crystals are reported based on a naphthylvinylpyridine coformer. The crystals are mechanically flexible and exhibit photosalient response to UV irradiation. We therefore show how multiple mechanical phenomena can be simultaneously designed into a single material by cocrystallization.
KW - Cocrystal
KW - Mechanical response
PY - 2022
DO - https://doi.org/10.1021/acs.cgd.2c00913
SN - 1528-7483
VL - 22
SP - 6838
EP - 6843
PB - ACS Publ.
CY - Washington, DC
AN - OPUS4-56561
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Linberg, Kevin
A1 - Emmerling, Franziska
A1 - Michalchuk, Adam
T1 - Unintended Rate Enhancement in Mechanochemical Kinetics by Using Poly(methyl methacrylate) Jars
JF - Crystal Growth & Design
N2 - Time-resolved in situ (TRIS) X-ray diffraction has changed how mechanochemical transformations are studied but requires the use of X-ray transparent jars often made from poly(methyl methacrylate) (PMMA). However, using PMMA jars can alter the apparent kinetics of mechanochemical polymorphism by an order of magnitude, questioning the interpretability of established TRIS methods. Our results suggest that rate enhancement in PMMA jars may not be dominated by chemical effects of the polymer, but rather a result of different equilibrium temperatures within the jar. These features must be better understood before control over mechanochemical reactions can be achieved.
KW - Mechanochemistry
KW - Organic compounds
KW - Polymers
KW - Materials
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-565276
DO - https://doi.org/10.1021/acs.cgd.2c01227
SN - 1528-7483
SP - 1
EP - 5
PB - ACS Publications
AN - OPUS4-56527
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Ravi, J.
A1 - Feiler, Torvid
A1 - Mondal, A.
A1 - Michalchuk, Adam
A1 - Reddy, C. M.
A1 - Bhattacharya, Biswajit
A1 - Emmerling, Franziska
A1 - Chandrasekar, R.
T1 - Plastically bendable organic crystals for monolithic and hybrid micro-optical circuits
JF - Advanced optical materials
N2 - Fluorescent plastically bendable crystals are a promising alternative to silicon-based materials for fabricating photonic integrated circuits, owing to their optical attributes and mechanical compliance. Mechanically bendable plastic organic crystals are rare. Their formation requires anisotropic intermolecular interactions and slip planes in the crystal lattice. This work presents three fluorescent plastically bendable crystalline materials namely, 2-((E)-(6-methylpyridin-2-ylimino)methyl)-4-chlorophenol (SB1), 2-((E)-(6-methylpyridin-2-ylimino)methyl)-4-bromophenol (SB2), and 2-((E)-(6-Bromopyridin-2-ylimino)methyl)-4-bromophenol (SB3) molecules. The crystal plasticity in response to mechanical stress facilitates the fabrication of various monolithic and hybrid (with a tip-to-tip coupling) photonic circuits using mechanical micromanipulation with an atomic force microscope cantilever tip. These plastically bendable crystals act as active (self-guiding of fluorescence) and passive waveguides both in straight and extremely bent (U-, J-, and O-shaped) geometries. These microcircuits use active and passive waveguiding principles and reabsorbance and energy-transfer mechanisms for their operation, allowing input-selective and direction-specific signal transduction.
KW - Flexible crystals
KW - Flexible waveguide
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-565302
DO - https://doi.org/10.1002/adom.202201518
SN - 2195-1071
SP - 1
EP - 10
PB - Wiley-VCH
CY - Weinheim
AN - OPUS4-56530
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Getenet, M.
A1 - Garcia-Ruiz, J. M.
A1 - Otálora, F.
A1 - Emmerling, Franziska
A1 - Al-Sabbagh, Dominik
A1 - Verdugo-Escamilla, E.
T1 - A comprehensive methodology for monitoring evaporitic mineral precipitation and hydrochemical evolution of saline lakes: The case of Lake Magadi soda brine (East African Rift Valley, Kenya)
JF - Crystal growth and design
N2 - Lake Magadi, East African Rift Valley, is a hyperalkaline and saline soda lake highly enriched in Na+, K+, CO32–, Cl–, HCO3–, and SiO2 and depleted in Ca2+ and Mg2+, where thick evaporite deposits and siliceous sediments have been forming for 100 000 years. The hydrogeochemistry and the evaporite deposits of soda lakes are subjects of growing interest in paleoclimatology, astrobiology, and planetary sciences. In Lake Magadi, different hydrates of sodium carbonate/bicarbonate and other saline minerals precipitate. The precipitation sequence of these minerals is a key for understanding the hydrochemical evolution, the paleoenvironmental conditions of ancient evaporite deposits, and industrial crystallization. However, accurate determination of the precipitation sequence of these minerals was challenging due to the dependency of the different hydrates on temperature, water activity, pH and pCO2, which could induce phase transformation and secondary mineral precipitation during sample handling. Here, we report a comprehensive methodology applied for monitoring the evaporitic mineral precipitation and hydrochemical evolution of Lake Magadi. Evaporation and mineral precipitations were monitored by using in situ video microscopy and synchrotron X-ray diffraction of acoustically levitated droplets. The mineral patterns were characterized by ex situ Raman spectroscopy, X-ray diffraction, and scanning electron microscopy. Experiments were coupled with thermodynamic models to understand the evaporation and precipitation-driven hydrochemical evolution of brines. Our results closely reproduced the mineral assemblages, patterns, and textural relations observed in the natural setting. Alkaline earth carbonates and fluorite were predicted to precipitate first followed by siliceous sediments. Among the salts, dendritic and acicular trona precipitate first via fractional crystallization─reminiscent of grasslike trona layers of Lake Magadi. Halite/villiaumite, thermonatrite, and sylvite precipitate sequentially after trona from residual brines depleted in HCO3–. The precipitation of these minerals between trona crystals resembles the precipitation process observed in the interstitial brines of the trona layers. Thermonatrite precipitation began after trona equilibrated with the residual brines due to the absence of excess CO2 input. We have shown that evaporation and mineral precipitation are the major drivers for the formation of hyperalkaline, saline, and SiO2-rich brines. The discrepancy between predicted and actual sulfate and phosphate ion concentrations implies the biological cycling of these ions. The combination of different in situ and ex situ methods and modeling is key to understanding the mineral phases, precipitation sequences, and textural relations of modern and ancient evaporite deposits. The synergy of these methods could be applicable in industrial crystallization and natural brines to reconstruct the hydrogeochemical and hydroclimatic conditions of soda lakes, evaporite settings, and potentially soda oceans of early Earth and extraterrestrial planets.
KW - Crystallization
KW - Precipitation
KW - Crystals
KW - Evaporation
KW - Minerals
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546712
DO - https://doi.org/10.1021/acs.cgd.1c01391
SN - 1528-7483
VL - 22
IS - 4
SP - 2307
EP - 2317
PB - ACS Publications
CY - Washington, DC
AN - OPUS4-54671
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Martins, Ines
A1 - Al-Sabbagh, Dominik
A1 - Bentrup, U.
A1 - Marquardt, Julien
A1 - Schmid, Thomas
A1 - Scoppola, E.
A1 - Kraus, Werner
A1 - Stawski, Tomasz
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Yusenko, Kirill
A1 - Weidner, Steffen
A1 - Emmerling, Franziska
T1 - Formation Mechanism of a Nano-Ring of Bismuth Cations and Mono-Lacunary Keggin-Type Phosphomolybdate
JF - Chemistry - A European Journal
N2 - A new hetero-bimetallic polyoxometalate (POM) nano-ring was synthesized in a one-pot procedure. The structure consists of tetrameric units containing four bismuth-substituted monolacunary Keggin anions including distorted [BiO8] cubes. The nano-ring is formed via self-assembly from metal precursors in aqueous acidic medium. The compound (NH4)16[(BiPMo11O39)4] ⋅ 22 H2O; (P4Bi4Mo44) was characterized by single-crystal X-ray diffraction, extended X-ray absorption fine structure spectroscopy (EXAFS), Raman spectroscopy, matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI-TOF), and thermogravimetry/differential scanning calorimetry mass spectrometry (TG-DSC-MS). The formation of the nano-ring in solution was studied by time-resolved in situ small- and wide-angle X-ray scattering (SAXS/WAXS) and in situ EXAFS measurements at the Mo−K and the Bi−L3 edge indicating a two-step process consisting of condensation of Mo-anions and formation of Bi−Mo-units followed by a rapid self-assembly to yield the final tetrameric ring structure.
KW - Bismuth
KW - In situ EXAFS
KW - In situ SAXS/WAXS
KW - Lacunary Keggin ion
KW - Polyoxometalates
KW - Self-assembly
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546823
DO - https://doi.org/10.1002/chem.202200079
SN - 0947-6539
VL - 28
IS - 27
SP - 1
EP - 7
PB - Wiley-VCH
CY - Weinheim
AN - OPUS4-54682
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Gugin, Nikita
A1 - Villajos Collado, José Antonio
A1 - Feldmann, Ines
A1 - Emmerling, Franziska
T1 - Mix and wait – a relaxed way for synthesizing ZIF-8
JF - RSC Advances
N2 - Herein we report the synthesis of a zeolitic imidazolate framework (ZIF-8) by an easy “mix and wait” procedure. In a closed vial, without any interference, the mixture of 2-methylimidazole and basic zinc carbonate assembles into the crystalline product with approx. 90% conversion after 70 h. The reaction exhibits sigmoidal kinetics due to the self-generated water which accelerates the reaction.
KW - In-situ analysis
KW - Mechanochemistry
KW - MOF
KW - Synthesis
KW - ZIF-8
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546841
DO - https://doi.org/10.1039/D2RA00740A
VL - 12
SP - 8940
EP - 8944
PB - Royal Society of Chemistry
AN - OPUS4-54684
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Michalchuk, Adam
A1 - Emmerling, Franziska
T1 - Time-Resolved InSitu Monitoring of Mechanochemical Reactions
JF - Angewandte Chemie International Edition
N2 - Mechanochemical transformations offer environmentally benign synthesis routes, whilst enhancing both the speed and selec-tivity of reactions. In this light, mechanochemistry promises to trans-form the way in which chemistry is done in both academia and indus-try but is greatly hindered by a current lack in mechanistic understand-ing. The continued development and use of time-resolved in situ(TRIS) approaches to monitor mechanochemical reactions provides a new dimension to elucidatethese fascinating transformations. We here discuss recent trends in method development that have pushed the boundaries of mechanochemical research. New features of mech-anochemical reactions obtained by TRIS techniques are subse-quently discussed, shedding light on how different TRISapproaches have beenused. Emphasis is placed on the strength of combining complementary techniques. Finally, we outline our views for the po-tential of TRIS methods in mechanochemical research, towards es-tablishing a new, environmentally benign paradigm in the chemical sciences
KW - Mechanochemistry
KW - Material synthesis
KW - Green chemistry
PY - 2022
DO - https://doi.org/10.1002/anie.202117270
SN - 1433-7851
SP - 1
EP - 15
PB - Wiley-VCH
CY - Weinheim
AN - OPUS4-54321
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Casali, C.
A1 - Feiler, Torvid
A1 - Heilmann, Maria
A1 - Braga, D.
A1 - Emmerling, Franziska
A1 - Grepioni, F.
T1 - Too much water? Not enough? In situ monitoring of the mechanochemical reaction of copper salts with dicyandiamide
JF - CrystEngComm
N2 - n situ monitoring of mechanochemical reactions between dicyandiamide (DCD) and CuX2 salts (X = Cl−, NO3−), for the preparation of compounds of agrochemical interest, showed the appearance of a number of phases. It is demonstrated that milling conditions, such as the amount of water added in wet grinding and/or the milling frequency, may affect the course of the mechanochemical reactions, and drive the reaction towards the formation of different products. It has been possible to discover by in situ monitored experiments two novel crystalline forms, namely the neutral complexes [Cu(DCD)2(OH2)2(NO3)2] (2) and [Cu(DCD)2(OH2)Cl2]·H2O (4), in addition to the previously known molecular salt [Cu(DCD)2(OH2)2][NO3]2·2H2O (1, DIVWAG) and neutral complex [Cu(DCD)2(OH2)Cl2] (3, AQCYCU), for which no synthesis conditions were available. Compounds 2 and 4 were fully characterized via a combination of solid-state techniques, including X-ray diffraction, Raman spectroscopy and TGA.
KW - Mechanochemistry
KW - In situ
PY - 2022
DO - https://doi.org/10.1039/d1ce01670a
VL - 24
IS - 6
SP - 1292
EP - 1298
PB - RSC
AN - OPUS4-54344
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -