TY - JOUR A1 - Fischer, Franziska A1 - Schmidt, M. U. A1 - Greiser, Sebastian A1 - Emmerling, Franziska T1 - The challenging case of the theophylline–benzamide cocrystal N2 - Theophylline has been used as an active pharmaceutical ingredient (API) in the treatment of pulmonary diseases, but due to its low water solubility reveals very poor bioavailability. Based on its different hydrogen-bond donor and acceptor groups, theophylline is an ideal candidate for the formation of cocrystals. The crystal structure of the 1:1 benzamide cocrystal of theophylline, C7H8N4O2·-C7H7NO, was determined from synchrotron X-ray powder diffraction data. The compound crystallizes in the tetragonal space group P41 with four Independent molecules in the asymmetric unit. The molecules form a hunter’s fence packing. The crystal structure was confirmed by dispersion-corrected DFT calculations. The possibility of salt formation was excluded by the results of Raman and 1H solid-state NMR spectroscopic analyses. KW - powder diffraction KW - theophylline KW - benzamide KW - cocrystal KW - crystal structure KW - active pharmaceutical ingredient KW - dispersion-corrected density-functional theory PY - 2016 DO - https://doi.org/10.1107/S2053229616002643 SN - 2053-2296 VL - 72 IS - 3 SP - 217 EP - 224 AN - OPUS4-35621 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schiffmann, J. A1 - Emmerling, Franziska A1 - Martins, Ines A1 - Van Wüllen, L. T1 - In-situ reaction monitoring of a mechanochemical ball mill reaction with solid state NMR N2 - We present an approach towards the in situ solid state NMR monitoring of mechanochemical reactions in a ball mill. A miniaturized vibration ball mill is integrated into the measuring coil of a home-built solid state NMR probe, allowing for static solid state NMR measurements during the mechanochemical reaction within the vessel. The setup allows to quantitatively follow the product evolution of a prototypical mechanochemical reaction, the formation of zinc phenylphosphonate from zinc acetate and phenylphosphonic acid. MAS NMR investigations on the final reaction mixture confirmed a reaction yield of 89% in a typical example. Thus, NMR spectroscopy may in the future provide complementary information about reaction mechanisms of mechanochemical reactions and team up with other analytical methods which have been employed to follow reactions in situ, such as Raman spectroscopy or X-ray diffraction. KW - Mechanochemistry KW - Solid state NMR KW - NMR probe Development PY - 2020 DO - https://doi.org/10.1016/j.ssnmr.2020.101687 VL - 109 SP - 101687 PB - Elsevier Inc. AN - OPUS4-51283 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Simões, R. G. A1 - Melo, P. L. T. A1 - Bernardes, C. E. S. A1 - Heilmann, Maria A1 - Emmerling, Franziska A1 - Minas da Piedade, M. E. T1 - Linking Aggregation in Solution, Solvation, and Solubility of Simvastatin: An Experimental and MD Simulation Study N2 - The solubility is generally thought to be higher if the solvent effectively solvates solute molecules that are well-separated from each other. The present work suggests, however, that the formation of large solute aggregates does not necessarily imply less effective solvation and lower solubility. Measurements of the solubility of simvastatin (one of the most commonly prescribed antihyperlipidemic drugs) in three solvents with different polarities and protic characters, led to the solubility order acetone > ethyl acetate > ethanol, in the full temperature range covered by the experiments (283–308 K). An analysis of the structures of the different solutions on the basis of molecular dynamics simulation results indicated that this trend seems to be determined by a balance between the solute tendency toward aggregation and the ability of the solvent to efficiently solvate it, by integrating the cluster structures, regardless of their size, and effectively establishing solvent–solute interactions. KW - Simvastatin KW - Solubility KW - API KW - Aggregation PY - 2021 DO - https://doi.org/10.1021/acs.cgd.0c01325 VL - 21 IS - 1 SP - 544 EP - 551 AN - OPUS4-52185 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) 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 - Alić, Jasna A1 - Schlegel, Moritz-Caspar A1 - Emmerling, Franziska A1 - Stolar, Tomislav T1 - Meeting the UN Sustainable Development Goals with Mechanochemistry N2 - Chemistry traditionally relies on reactions in solution, but this method is increasingly problematic due to the scale of chemical processes and their economic and environmental impact. Handling residual chemical waste, including solvents, incurs significant costs and environmental pressure. Conversely, novel chemical approaches are needed to address pressing societal issues such as climate change, energy scarcity, food insecurity, and waste pollution. Mechanochemistry, a sustainable chemistry discipline that uses mechanical action to induce chemical reactivity without bulk solvents, is a hot topic in academic research on sustainable and green chemistry. Given its fundamentally different working principles from solution chemistry, mechanochemistry offers more efficient chemical processes and the opportunity to design new chemical reactions. Mechanochemistry has a profound impact on many urgent issues facing our society and it is now necessary to use mechanochemistry to address them. This Minireview aims to provide a guide for using mechanochemistry to meet the United Nations (UN) Sustainable Development Goals (SDGs), thereby contributing to a prosperous society. Detailed analysis shows that mechanochemistry connects with most UN SDGs and offers more cost‐efficiency than other approaches together with a superior environmental performance. KW - Mechanochemistry KW - SDGs PY - 2024 DO - https://doi.org/10.1002/anie.202414745 SP - 1 EP - 3 PB - Wiley AN - OPUS4-61108 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 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 - Tumanova, N. A1 - Tumanov, N. A1 - Robeyns, K. A1 - Fischer, Franziska A1 - Fusaro, L. A1 - Morelle, F. A1 - Ban, V. A1 - Hautier, G. A1 - Filinchuk, Y. A1 - Wouters, J. A1 - Leyssens, T. A1 - Emmerling, Franziska T1 - Opening Pandora’s Box: Chirality, Polymorphism, and Stoichiometric Diversity in Flurbiprofen/Proline Cocrystals N2 - Proline has been widely used for various cocrystallization applications, including pharmaceutical cocrystals. Combining enantiopure and racemic flurbiprofen and proline, we discovered 18 new crystal structures. Liquid-assisted grinding proved highly efficient to explore all the variety of crystal forms. A unique combination of stateof-the-art characterization techniques, comprising variable temperature in situ X-ray diffraction and in situ ball-milling, along with other physicochemical methods and density functional theory calculations, was indispensable for identifying all the phases. Analyzing the results of in situ ball-milling, we established a stepwise mechanism for the formation of several 1:1 cocrystals via an intermediate 2:1 phase. The nature of the solvent in liquidassisted grinding was found to significantly affect the reaction rate and, in some cases, the reaction pathway. KW - Mechanochemistry KW - Polymorphs KW - In situ PY - 2018 UR - https://pubs.acs.org/doi/abs/10.1021/acs.cgd.7b01436 DO - https://doi.org/10.1021/acs.cgd.7b01436 VL - 18 IS - 2 SP - 954 EP - 961 PB - American Chemical Society AN - OPUS4-44365 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Breitfeld, Steffen A1 - Scholz, G. A1 - Emmerling, Franziska A1 - Kemnitz, E. T1 - BaF-benzenedicarboxylate: the first mechanochemical N2 - Anewbariumcoordination polymer, BaF-benzenedicarboxylate (BaF(p-BDC)0.5), with fluorine directly coordinated to the metal cation, was prepared by mechanochemical synthesis routes. Phase-pure BaF-benzenedicarboxylate was synthesized by milling starting either from barium hydroxide or from Barium acetate as sources for barium cations. In both cases, the second reactant was 1,4-benzenedicarboxylic acid (H2(p-BDC)). Ammonium fluoride was used as fluorinating agent directly at milling. This is the first mechanochemical synthesis of coordination polymers where fluorine is directly coordinated to the metal cation. Following the second possibility, barium acetate fluoride (Ba(OAc)F) is formed as ntermediate product after milling, and the new coordination polymer is accessible only after washing with water and dimethyl sulfoxide. The new compound BaF(p-BDC)0.5 was characterized by X-ray powder diffraction, FTIR-, and 19F, 1H-13C CP MAS NMR spectroscopies, DTA-TG, and elemental Analysis. KW - Milling KW - MOF PY - 2018 DO - https://doi.org/10.1007/s10853-018-2331-3 SN - 0022-2461 VL - 53 IS - 19 SP - 13682 EP - 13689 PB - Springer AN - OPUS4-45677 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dolai, Malay A1 - Saha, Urmila A1 - Goswami, Juli Nanda A1 - Bhattacharya, Biswajit A1 - Emmerling, Franziska A1 - Ifseisi, Ahmad A. A1 - Biswas, Surajit ED - Bhattacharya, Biswajit T1 - Nickel(II)-mediated in situ complex formation with unexpected ligand transformations: crystal structures, DFT calculations, and catalytic activity in CO2 fixation reactions N2 - Two transformed ligands, namely 1,3,5-triazapentadienato(imidoylamidinato) and N-(methoxy(pyrimidin-2-yl)(pyrimidine-2-carboxamido)methyl)pyrimidine-2-carboxamide, are reported here as the first products derived from 2-cyano pyridine/pyrimidine, respectively, under nickel metal mediation in the presence of hydroxylamine hydrochloride in situ. Two different nickel-coordinated complexes (1 and 2) were formed. Single crystal X-ray diffraction revealed that complex 1 is a mononuclear complex with tetra-coordinated square planar geometry, whereas complex 2 is a dinuclear complex with hexa-coordinated distorted octahedral geometry. The synthetic pathways of both transformed ligands are explained with the support of energy calculations of different states via density functional theory (DFT) calculations. The catalytic addition reactions of epoxides and carbon dioxide efficiently produce organic cyclic carbonates in the presence of complexes 1–2, attributed to the presence of Lewis acidic nickel and Lewis basic centers, such as free amine, imine, methoxy, or nitrogen in complexes 1 and 2. Under mild reaction conditions (1 atm CO2 pressure and 60 °C temperature), different types of epoxides (exocyclic, endocyclic, and aromatic epoxides) yield high levels of respective cyclic carbonates in the presence of both complexes 1–2 as catalysts, with tert-butylammonium bromide (TBAB) acting as a co-catalyst. The high turnover number (TON) and turnover frequency (TOF) of these catalytic reactions clearly indicate the efficacy of the two catalysts. KW - Catalytic activity in CO2 fixation reactions DFT calculations KW - Nickel(II)-complex KW - In situ complex formation KW - Crystal Structure PY - 2025 DO - https://doi.org/10.1039/d4nj01801j SN - 1369-9261 VL - 49 IS - 11 SP - 4451 EP - 4463 PB - Royal Society of Chemistry (RSC) AN - OPUS4-62782 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stroh, Julia A1 - Meng, Birgit A1 - Emmerling, Franziska T1 - Deterioration of hardened cement paste under combined sulphatechloride attack investigated by synchrotron XRD N2 - The exact mechanisms of the phase transitions caused by a combined sulphate-chloride attack are discussed controversially. The main points concern the mutual influences of sulphate and chloride ions during the secondary binding processes of these anions within cement hydrate phases. We simulated combined sulphate-chloride attack under laboratory conditions using solutions containing NaCl and Na2SO4 in different concentrations. Three sample compositions were used for the preparation of the specimens. In two of them, 30% of Portland cement was replaced by supplementary cementitious materials (fly ash, slag). The phase distribution in the samples was determined using synchrotron X-ray diffraction. The analysis with high spatial resolution allows the localisation of the secondary phase formation in the microstructural profile of the sample. A mechanism of the phase developments under combined sulphate-chloride attack is derived. KW - Cement paste KW - Sulphate-chloride attack KW - Portland cement KW - Mineral additions PY - 2016 DO - https://doi.org/10.1016/j.solidstatesciences.2016.04.002 IS - 56 SP - 29 EP - 44 PB - Elsevier Masson SAS CY - Issy les Moulineaux cedex; France AN - OPUS4-35936 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kulla, Hannes A1 - Michalchuk, Adam A1 - Emmerling, Franziska T1 - Manipulating the dynamics of mechanochemical ternary cocrystal formation N2 - The mechanism of ternary cocrystal formation, and the potential role of intermediate binary phases, has been debated for some time. We report here the first in situ real-time monitoring of two prototypic ternary cocrystals. Our results suggest that the question is more complicated than previously considered. The mechanism of mechanochemical ternary cocrystal formation depends on the milling conditions, here the milling frequency and addition of liquid. Binary phases can form under certain conditions, but do not act as intermediates in the formation of the ternary cocrystals. Rather, binary phases are competitive with the ternary phase, and their formation appears to compete with that of the ternary components. The presence of binary phases leads to an increase in the overall reaction time. The results reported here offer the first insights into the true complexities of mechanochemical multi-component synthesis of higher order multi-component crystals and demonstrate a new understanding of the influence of milling condition for the study of mechanisms and kinetics. KW - Mechanochemistry KW - In situ KW - Cocrystal PY - 2019 UR - https://pubs.rsc.org/en/content/articlepdf/2019/cc/c9cc03034d DO - https://doi.org/10.1039/c9cc03034d SN - 1364-548X VL - 55 IS - 66 SP - 9793 EP - 9796 PB - RSC AN - OPUS4-48613 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Akhmetova, Irina A1 - Schuzjajew, K. A1 - Wilke, M. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Rademann, K. A1 - Roth, C. A1 - Emmerling, Franziska T1 - Synthesis, characterization and in situ monitoring of the mechanochemical reaction process of two manganese(II)-phosphonates with N-containing ligands N2 - Two divalent manganese aminophosphonates, manganese mono (nitrilotrimethylphosphonate) (MnNP3) and manganese bis N-(carboxymethyl)iminodi(methylphosphonate)) (Mn(NP2AH)2), have been prepared by mechanochemical synthesis and characterized by powder X-ray diffraction (PXRD). The structure of the novel compound Mn(NP2AH)2 was determined from PXRD data. MnNP3 as well as Mn(NP2AH)2 exhibits a chain-like structure. In both cases, the manganese atom is coordinated by six oxygen atoms in a distorted octahedron. The local coordination around Mn was further characterized by extended X-ray absorption fine structure. The synthesis process was followed in situ by synchrotron X-ray diffraction revealing a three-step reaction mechanism. The asprepared manganese(II) phosphonates were calcined on air. All samples were successfully tested for their suitability as catalyst material in the oxygen evolution reaction. KW - Mechanochemistry KW - In situ KW - XRD PY - 2018 DO - https://doi.org/10.1007/s10853-018-2608-6 SN - 0022-2461 SN - 1573-4803 VL - 53 IS - 19 SP - 13390 EP - 13399 PB - Springer Science + Business Media B.V. AN - OPUS4-45673 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - de Oliveira Guilherme Buzanich, Ana A1 - Kulow, Anicó A1 - Kabelitz, Anke A1 - Grunewald, C. A1 - Seidel, R. A1 - Chapartegui-Arias, Ander A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Emmerling, Franziska A1 - Beyer, S. T1 - Observation of early ZIF-8 crystallization stages with X-ray absorption spectroscopy N2 - The present study investigates early stages of ZIF-8 crystallization up to 5 minutes post mixing of precursor solutions. Dispersive X-ray Absorption Spectroscopy (DXAS) provides a refined understanding of the evolution of the coordination environment during ZIF-8 crystallization. Linear Combination Fiting (LCF) suggests tetrakis(1-methylimidazole)zinc2+ to be a suitable and stable mononuclear structure analogue for some early stage ZIF-8 intermediates. Our results pave the way for more detailed studies on physico-chemical aspects of ZIF-8 crystallization to better control tailoring ZIF-8 materials for specific applications. KW - In-situ KW - XANES KW - ZIF-8 KW - Crystallization PY - 2020 DO - https://doi.org/10.1039/D0SM01356K SN - 1744-6848 VL - 17 IS - 2 SP - 331 EP - 334 PB - Royal Scociety of Chemistry AN - OPUS4-51723 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - de Olivera, Paulo A1 - Michalchuk, Adam A1 - de Oliveira Guilherme Buzanich, Ana A1 - Bienert, Ralf A1 - Torresi, R. A1 - Camargo, P. A1 - Emmerling, Franziska T1 - Tandem X-ray absorption spectroscopy and scattering for in situ time-resolved monitoring of gold nanoparticle mechanosynthesis N2 - Current time-resolved in situ approaches limit the scope of mechanochemical investigations possible. Here we develop a new, general approach to simultaneously follow the evolution of bulk atomic and electronic structure during a mechanochemical synthesis. This is achieved by coupling two complementary synchrotron-based X-ray methods: X-ray absorption spectroscopy (XAS) and X-ray diffraction. We apply this method to investigate the bottom-up mechanosynthesis of technologically important Au micro and nanoparticles in the presence of three different reducing agents, hydroquinone, sodium citrate, and NaBH4. Moreover, we show how XAS offers new insight into the early stage generation of growth species (e.g. monomers and clusters), which lead to the subsequent formation of nanoparticles. These processes are beyond the detection capabilities of diffraction methods. This combined X-ray approach paves the way to new directions in mechanochemical research of advanced electronic materials. KW - Mechanochemistry KW - XANES KW - X-ray diffraction KW - Nano particles PY - 2020 DO - https://doi.org/10.1039/d0cc03862h SN - 1364-548X VL - 56 SP - 10329 EP - 10332 PB - Royal Society of Chemistry AN - OPUS4-51760 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Emmerling, Franziska A1 - Stock, Norbert A1 - Tadei, Marco A1 - Demel, Jan A1 - Cabeza, Aurelio A1 - Viviani, Riccardo A1 - Demadis, Konstantinos A1 - Vassaki, Maria T1 - New directions in metal phosphonate and phosphinate chemistry N2 - In September 2018, the First European Workshop on Metal Phosphonates Chemistry brought together some prominent researchers in the field of metal phosphonates and phosphinates with the aim of discussing past and current research efforts and identifying future directions. The scope of this perspective article is to provide a critical overview of the topics discussed during the workshop, which are divided into two main areas: synthesis and characterisation, and applications. In terms of synthetic methods, there has been a push towards cleaner and more efficient approaches. This has led to the introduction of high-throughput synthesis and mechanochemical synthesis. The recent success of metal–organic frameworks has also promoted renewed interest in the synthesis of porous metal phosphonates and phosphinates. Regarding characterisation, the main advances are the development of electron diffraction as a tool for crystal structure determination and the deployment of in situ characterisation techniques, which have allowed for a better understanding of reaction pathways. In terms of applications, metal phosphonates have been found to be suitable materials for several purposes: they have been employed as heterogeneous catalysts for the synthesis of fine chemicals, as solid sorbents for gas separation, notably CO2 capture, as materials for electrochemical devices, such as fuel cells and rechargeable batteries, and as matrices for drug delivery. KW - Metal phosphonates KW - Metal–organic frameworks KW - X-ray and electron diffraction PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-484346 DO - https://doi.org/10.3390/cryst9050270 SN - 2073-4352 VL - 9 IS - 5 SP - 270, 1 EP - 36 PB - MDPI AN - OPUS4-48434 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Burek, K. A1 - Dengler, J. A1 - Emmerling, Franziska A1 - Feldmann, Ines A1 - Kumke, M. U. A1 - Stroh, Julia T1 - Lanthanide Luminescence Revealing the Phase Composition in Hydrating Cementitious Systems N2 - The hydration process of Portland cement in a cementitious system is crucial for development of the high-quality cementbased construction material. Complementary experiments of Xray diffraction analysis (XRD), scanning electron microscopy (SEM) and time-resolved laser fluorescence spectroscopy (TRLFS) using europium (Eu(III)) as an optical probe are used to analyse the hydration process of two cement systems in the absence and presence of different organic admixtures. We Show that different analysed admixtures and the used sulphate carriers in each cement system have a significant influence on the hydration process, namely on the time-dependence in the formation of different hydrate phases of cement. Moreover, the effect of a particular admixture is related to the type of sulphate carrier used. The quantitative information on the amounts of the crystalline cement paste components is accessible via XRD analysis. Distinctly different morphologies of ettringite and calcium-silicate-hydrates (C-S-H) determined by SEM allow visual conclusions about formation of these phases at particular ageing times. The TRLFS data provides information about the admixture influence on the course of the silicate reaction. The dip in the dependence of the luminescence decay times on the hydration time indicates the change in the structure of C-S-H in the early hydration period. Complementary information from XRD, SEM and TRLFS provides detailed information on distinct periods of the cement hydration process. KW - Cement admixtures KW - Cement hydration KW - Europium KW - Luminescence KW - SEM KW - X-ray diffraction PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-504842 DO - https://doi.org/10.1002/open.201900249 VL - 8 IS - 12 SP - 1441 EP - 1452 PB - Wiley-VCH AN - OPUS4-50484 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Haferkamp, Sebastian A1 - Paul, Andrea A1 - Michalchuk, Adam A1 - Emmerling, Franziska T1 - Unexpected polymorphism during a catalyzed mechanochemical Knoevenagel condensation N2 - The transformation of a base-catalyzed, mechano-assisted Knoevenagel condensation of mono-fluorinated benzaldehyde derivatives (p-, m-, o-benzaldehyde) with malonodinitrile was investigated in situ and in real time. Upon milling, the para-substituted product was found to crystallize initially into two different polymorphic forms, depending on the quantity of catalyst used. For low catalyst concentrations, a mechanically metastable phase (monoclinic) was initially formed, converting to the mechanically stable phase (triclinic) upon further grinding. Instead, higher catalyst concentrations crystallize directly as the triclinic product. Inclusion of catalyst in the final product, as evidenced by mass spectrometric analysis, suggests this complex polymorphic pathway may be due to seeding effects. Multivariate analysis for the in situ Raman spectra supports this complex formation pathway, and offers a new approach to monitoring multi-phase reactions during ball milling. KW - Ball milling KW - C-C coupling KW - In situ KW - Mechanochemistry KW - Multivariate data analysis PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-481872 DO - https://doi.org/10.3762/bjoc.15.110 SN - 1860-5397 VL - 15 SP - 1141 EP - 1148 PB - Beilstein Insitut CY - Frankfurt am Main AN - OPUS4-48187 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bhattacharya, Biswajit A1 - Michalchuk, Adam A1 - Silbernagl, Dorothee A1 - Rautenberg, Max A1 - Schmid, Thomas A1 - Feiler, Torvid A1 - Reimann, K. A1 - Ghalgaoui, A. A1 - Sturm, Heinz A1 - Paulus, B. A1 - Emmerling, Franziska T1 - A Mechanistic Perspective on Plastically Flexible Coordination Polymers N2 - Mechanical flexibility in single crystals of covalently bound materials is a fascinating and poorly understood phenomenon. We present here the first example of a plastically flexible one-dimensional (1D) coordination polymer. The compound [Zn(m-Cl)2(3,5-dichloropyridine)2]n is flexible over two crystallographic faces. Remarkably, the single crystal remains intact when bent to 1808. A combination of microscopy, diffraction, and spectroscopic studies have been used to probe the structural response of the crystal lattice to mechanical bending. Deformation of the covalent polymer chains does not appear to be responsible for the observed macroscopic bending. Instead, our results suggest that mechanical bending occurs by displacement of the coordination polymer chains. Based on experimental and theoretical evidence, we propose a new model for mechanical flexibility in 1D coordination polymers. Moreover, our calculations propose a cause of the different mechanical properties of this compound and a structurally similar elastic material KW - Coordination polymer KW - Flexible crystals KW - Mechanical properties KW - Plastic deformation PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-504755 DO - https://doi.org/10.1002/anie.201914798 VL - 59 IS - 14 SP - 5557 EP - 5561 PB - Wiley-VCH AN - OPUS4-50475 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Beyer, Sebastian A1 - Schürmann, Robin A1 - Feldmann, Ines A1 - Blocki, A. A1 - Bald, Ilko A1 - Schneider, Rudolf A1 - Emmerling, Franziska T1 - Maintaining Stable Zeolitic Imidazolate Framework (ZIF) Templates during Polyelectrolyte Multilayer Coating N2 - Equipping ZIF particles with a polyelectrolyte membrane provides functional groups at their interface, enabling further conjugations necessary for applications such as targeted drug delivery. Previous approaches to coat ZIF particles with polyelectrolytes led to surface corrosion of the template material. This work overcomes previous limitations by performing a Layer-by-Layer (LbL) polyelectrolyte coating onto ZIF-8 and ZIF-67 particles in nonaqueous environment. Using the 2-methylimidazolium salt of polystyrensulfonic acid instead of the acid itself and polyethyleneimine in methanol led to intact ZIF particles after polyelectrolyte coating. This was verified by electron microscopy. Further, zetapotential and atomic force microscopy measurements confirmed a continuous polyelectrolyte multilayer built up. The here reported adaption to the well-studied (LbL) polyelectrolyte selfassembly process provides a facile method to equip ZIF particles with a nanometer thin polyelectrolyte multilayer membrane. KW - Zeolithe KW - Molecular Organic Frameworks KW - MOF KW - ZIF KW - Layer-by-Layer KW - Beschichtung KW - Polyelektrolyt PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-447729 DO - https://doi.org/10.1016/j.colcom.2017.11.004 SN - 2215-0382 VL - 22 SP - 14 EP - 17 PB - Elsevier B.V. CY - Amsterdam, NL AN - OPUS4-44772 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Michalchuk, Adam A1 - Boldyreva, E. A1 - Belenguer, A. M. A1 - Emmerling, Franziska A1 - Boldyrev, V. V. T1 - Tribochemistry, mechanical alloying, mechanochemistry: what is in a name? N2 - Over the decades, the application of mechanical force to influence chemical reactions has been called by various names: mechanochemistry, tribochemistry, mechanical alloying, to name but a few. The evolution of these terms has largely mirrored the understanding of the field. But what is meant by these terms, why have they evolved, and does it really matter how a process is called? Which parameters should be defined to describe unambiguously the experimental conditions such that others can reproduce the results, or to allow a meaningful comparison between processes explored under different conditions? Can the information on the process be encoded in a clear, concise, and self-explanatory way? We address these questions in this Opinion contribution, which we hope will spark timely and constructive discussion across the international mechanochemistry community. KW - Mechanochemistry KW - Tribochemistry KW - Mechanical alloying KW - Tribology KW - Mechanical activation KW - Nomenclature KW - Mechanochemical pictographs PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-523291 DO - https://doi.org/10.3389/fchem.2021.685789 SN - 2296-2646 VL - 9 SP - 1 EP - 29 PB - Frontiers Media CY - Lausanne AN - OPUS4-52329 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -