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 - Linberg, Kevin A1 - Röder, Bettina A1 - Al-Sabbagh, Dominik A1 - Emmerling, Franziska A1 - Michalchuk, Adam T1 - Controlling polymorphism in molecular cocrystals by variable temperature ball milling JF - Faraday Discussions N2 - Mechanochemistry offers a unique opportunity to modify and manipulate crystal forms, often providing new products as compared with conventional solution methods. While promising, there is little known about how to control the solid form through mechanochemical means, demanding dedicated investigations. Using a model organic cocrystal system (isonicotinamide:glutaric acid), we here demonstrate that with mechanochemistry, polymorphism can be induced in molecular solids under conditions seemingly different to their conventional thermodynamic (thermal) transition point. Whereas Form II converts to Form I upon heating to 363 K, the same transition can be initiated under ball milling conditions at markedly lower temperatures (348 K). Our results indicate that mechanochemical techniques can help to reduce the energy barriers to solid form transitions, offering new insights into controlling polymorphic forms. Moreover, our results suggest that the nature of mechanochemical transformations could make it difficult to interpret mechanochemical solid form landscapes using conventional equilibrium-based tools. KW - Mechanochemistry KW - Polymorphism KW - TRIS PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-564728 DO - https://doi.org/10.1039/d2fd00115b SP - 1 EP - 16 PB - Royal Society of Chemistry AN - OPUS4-56472 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 - 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 - Rautenberg, Max A1 - Gernhard, M. A1 - Radnik, Jörg A1 - Witt, Julia A1 - Roth, C. A1 - Emmerling, Franziska T1 - Mechanochemical synthesis of fluorine-containing Co-doped zeolitic imidazolate frameworks for producing electrocatalysts JF - Frontiers in chemistry N2 - Catalysts derived from pyrolysis of metal organic frameworks (MOFs) are promising candidates to replace expensive and scarce platinum-based electrocatalysts commonly used in polymer electrolyte membrane fuel cells. MOFs contain ordered connections between metal centers and organic ligands. They can be pyrolyzed into metal- and nitrogen-doped carbons, which show electrocatalytic activity toward the oxygen reduction reaction (ORR). Furthermore, metal-free heteroatom-doped carbons, such as N-F-Cs, are known for being active as well. Thus, a carbon material with Co-N-F doping could possibly be even more promising as ORR electrocatalyst. Herein, we report the mechanochemical synthesis of two polymorphs of a zeolitic imidazole framework, Co-doped zinc 2-trifluoromethyl-1H-imidazolate (Zn0.9Co0.1(CF3-Im)2). Time-resolved in situ X-ray diffraction studies of the mechanochemical formation revealed a direct conversion of starting materials to the products. Both polymorphs of Zn0.9Co0.1(CF3-Im)2 were pyrolyzed, yielding Co-N-F containing carbons, which are active toward electrochemical ORR. KW - Mechanochemistry KW - Metal-organic-frameworks KW - Nobel-metal free electrocatalysis PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546833 DO - https://doi.org/10.3389/fchem.2022.840758 SN - 2296-2646 VL - 10 IS - 840758 SP - 1 EP - 13 PB - Frontiers Media CY - Lausanne AN - OPUS4-54683 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 - Emmerling, Franziska A1 - Martins, Ines T1 - Carbamazepine Dihydroxybenzoic Acid Cocrystals: Exploring Packing Interactions and Reaction Kinetics JF - Crystal Growth and Design N2 - Herein, we present the mechanochemical formation of three new cocrystals containing the active pharmaceutical ingredient carbamazepine and dihydroxybenzoic acids as coformers (CBZ:2,4-DHBA 1:1, CBZ:2,5-DHBA 1:1, and CBZ:2,6-DHBA 1:1). Rietveld methods were used for three different purposes: (i) refining all structures solved using powder X-ray diffraction, (ii) performing a quantitative phase analysis of the diffraction data collected from ex situ mechanochemical reactions at different milling times, and (iii) determining the cocrystallization kinetic profiles. The rate of cocrystallization was found to be higher for the formation of CBZ:2,4-DHBA and CBZ:2,6-DHBA, reaching an equilibrium after 600 s of milling. In the case of CBZ:2,5-DHBA a short induction period of 20 s was detected prior to the start of the reaction and an equilibrium was reached after 1200 s. An empirical trend between the rate of cocrystallization and the structural complexity of the cocrystal product was found. The slowest cocrystallization rate observed for CBZ:2,5-DHBA corresponds to the crystal structure deviating substantially from the hydrogen-bonding motif found in the reactants. KW - Mechanochemistry KW - In situ real-time monitoring KW - Kinetics PY - 2021 DO - https://doi.org/10.1021/acs.cgd.1c00902 VL - 21 IS - 12 SP - 6961 EP - 6970 PB - ACS Publications AN - OPUS4-54407 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 - TY - CONF A1 - Emmerling, Franziska T1 - In situ investigations of mechanochemical processes N2 - Overview of the present BAM activities in the field of in situ analytics of mechanochemical processes. Recent results for the synthesis of metal organic frameworks and cocrystals are presented. T2 - HZB Seminar CY - Online meeting DA - 21.01.2022 KW - Mechanochemistry KW - In situ real-time monitoring PY - 2022 AN - OPUS4-54296 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Casali, L. A1 - Broll, V. A1 - Ciurili, S. A1 - Braga, D. A1 - Emmerling, Franziska A1 - Gepioni, F. T1 - Facilitating Nitrification Inhibition through Green, Mechanochemical Synthesis of a Novel Nitrapyrin Complex JF - Crystal Growth and Design N2 - Nitrapyrin (NP) is applied to cultivated soils to inhibit the enzymatic activity of ammonia monooxygenase (AMO), but its poor aqueous solubility and high volatility severely limit its application. β-Cyclodextrin (β-CD) is commonly used to form inclusion complexes with hydrophobic molecules, improving water solubility and stability upon complexation. Here we report on the mechanochemical synthesis of the inclusion complex β-CD·NP, characterized via a combination of solid-state techniques, including exsitu and in situ X-ray diffraction, Raman and NMR spectroscopies, transmission electron microscopy, and energy dispersive X-ray spectroscopy. The pure inhibitor NP was also structurally characterized. The β-CD·NP complex presents improved solubility and thermal stability, and still inhibits the enzymatic activity of AMO with high efficacy. All results indicate that the inclusion of NP into β-CD represents a viable route for the preparation of a novel class of inhibitors, with improved properties related to stability, water solubility, and good inhibition activity. KW - Mechanochemistry KW - Nitrification PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-537154 DO - https://doi.org/10.1021/acs.cgd.1c00681 VL - 21 IS - 10 SP - 5792 EP - 5799 PB - ACS Publications AN - OPUS4-53715 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Shaken not stirred: enhancing the flavor of mechanochemistry N2 - Mechanochemistry is increasingly used for synthesizing soft matter materials including metal organic compounds and cocrystals.1 The ever-increasing interest in this method is contrasted by a limited mechanistic understanding of the mechanochemical reactivity and selectivity. Time-resolved in situ investigations of milling reactions provide direct insights in the underlying mechanisms.2-4 We recently introduced different setups enabling in situ investigation of mechanochemical reactions using synchrotron XRD combined with Raman spectroscopy and thermography. The presented setup allows the detection of crystalline, amorphous, eutectic, and liquid intermediates. Furthermore, the chemical composition of the reaction mixture was found to be directly correlated with changes in the temperature profile of the reaction. The resulting deeper kinetic and thermodynamic understanding of milling processes is the key for future optimization of mechanochemical syntheses. In this contribution, we will discuss our recent results investigating the formation of (polymorphic) cocrystals and coordination polymers.2,3,5 Our results indicate that in situ investigation of milling reactions offer a new approach to tune and optimize mechanochemical syntheses. T2 - BCA/BACG joint spring meeting CY - Online meeting DA - 29.03.2021 KW - Mechanochemistry KW - Cocrystals KW - Crystal Engineering PY - 2021 AN - OPUS4-53995 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Shaken not stirred: in situ investigations of mechanochemical processes N2 - Mechanochemistry has emerged as one of the most interesting synthetic protocols to produce new materials. The development of mechanochemistry as a synthetic method is supported by excellent research by many groups worldwide in a wide range of applications. The potential of mechanochemistry is also reflected in the inclusion in IUPAC’s 10 chemical innovations that will change our world’.[1] Solvent-free methodologies lead to unique chemical processes during synthesis with the consequent formation of martials with new properties.2 In this contribution, we will discuss our recent results investigating the formation of (polymorphic) cocrystals, coordination polymers, metal oxides and metal nanoparticles.[3-8] We introduced different setups enabling in situ investigation of mechanochemical reactions using synchrotron XRD combined with Raman spectroscopy and thermography. T2 - Deutsche Kristallzüchtertagung CY - Berlin, Germany DA - 06.10.2021 KW - Mechanochemistry KW - In situ real-time monitoring KW - Crystal PY - 2021 AN - OPUS4-53996 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lampronti, G. A1 - Michalchuk, Adam A1 - Mazzeo, P. A1 - Belenguer, Ana A1 - Sanders, J. K. M. A1 - Bacchi, A. A1 - Emmerling, Franziska T1 - Changing the game of time resolved X-ray diffraction on the mechanochemistry playground by downsizing JF - Nature Communications N2 - Time resolved in situ (TRIS) monitoring has revolutionised the study of mechanochemical transformations but has been limited by available data quality. Here we report how a combination of miniaturised grinding jars together with innovations in X-ray powder diffraction data collection and state-of-the-art analysis strategies transform the power of TRIS synchrotron mechanochemical experiments. Accurate phase compositions, comparable to those obtained by ex situ measurements, can be obtained with small sample loadings. Moreover, microstructural parameters (crystal size and microstrain) can be also determined with high confidence. This strategy applies to all chemistries, is readily implemented, and yields high-quality diffraction data even using a low energy synchrotron source. This offers a direct avenue towards the mechanochemical investigation of reactions comprising scarce, expensive, or toxic compounds. Our strategy is applied to model systems, including inorganic, metal-organic, and organic mechanosyntheses, resolves previously misinterpreted mechanisms in mechanochemical syntheses, and promises broad, new directions for mechanochemical research. KW - Mechanochemistry KW - Synchrotron radiation KW - Material synthesis PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-535932 DO - https://doi.org/10.1038/s41467-021-26264-1 SN - 2041-1723 VL - 12 IS - 1 SP - 1 EP - 9 PB - Nature Publishing Group CY - London AN - OPUS4-53593 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Martins, I. A1 - Carta, M. A1 - Haferkamp, Sebastian A1 - Feiler, Torvid A1 - Delogu, F. A1 - Colacino, E. A1 - Emmerling, Franziska T1 - Mechanochemical N‑Chlorination Reaction of Hydantoin: In Situ Real-Time Kinetic Study by Powder X‑ray Diffraction and Raman Spectroscopy JF - Acs Sustainable Chemistry & Engineering N2 - Mechanochemistry has become a valuable tool for the synthesis of new molecules, especially in the field of organic chemistry. In the present work, we investigate the kinetic profile of the chlorination reaction of N-3-ethyl-5,5-dimethylhydantoin (EDMH) activated and driven by ball milling. The reaction has been carried out using 2 mm, 4 mm, 5 mm, 6 mm, and 8 mm ball sizes in a new small custom-made Perspex milling jar. The Crystal structure of the starting material EDMH and the 1-chloro-3-ethyl5,5′-dimethyl hydantoin (CEDMH) chlorination product was solved by single-crystal X-ray diffraction. The reaction was monitored, in situ and in real time, by both powder X-ray diffraction (PXRD) and Raman spectroscopy. Our kinetic data show that the reaction progress to equilibrium is similar at all milling ball sizes. The induction period is very short (between 10 and 40 s) when using 4 mm, 5 mm, 6 mm, and 8 mm balls. For the reaction performed with a 2 mm ball, a significantly longer induction period of 9 min was observed. This could indicate that an initial energy accumulation and higher mixing efficiency are necessary before the reaction starts. Using different kinetic models, we found that the amount of powder affected by critical loading conditions during individual impacts is significantly dependent on the ball size used. An almost linear correlation between the rate of the chemical transformations and the ball volume is observed. KW - Mechanochemistry KW - In situ real-time monitoring KW - N-Chlorination KW - Kinetics KW - Hydantoin KW - Powder X-ray diffraction KW - Raman spectroscopy PY - 2021 DO - https://doi.org/10.1021/acssuschemeng.1c03812 VL - 9 IS - 37 SP - 12591 EP - 12601 AN - OPUS4-53541 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Souza, B. A1 - Chauque, S. A1 - de Oliveira, P. A1 - Emmerling, Franziska A1 - Torresi, R. T1 - Mechanochemical optimization of ZIF-8/Carbon/S8 composites for lithium-sulfur batteries positive electrodes JF - Journal of Electroanalytical Chemistry N2 - The application of lithium-sulfur (Li-S) batteries is still limited by their rapid capacity fading. The pulverization of the sulfur positive electrode after the lithiation and the consequence dissolution of long chain polysulfides in organic solvents lead to the shuttle effect. To address these issues, here we report the mechanochemical preparation of ZIF-8 (Zeolitic Imidazole Framework-8)-based composites as sulfur hosts for positive electrodes in Li-S batteries. We studied different methods for the incorporation of conductive carbon. Also, the replacement of Zn2+ metal centers by other bivalent metals (Cu2+, Co2+ and Ni2+), enabled the preparation of other ZIF-8-based materials. The positive electrode ZIF-8/C/S8 showed initial discharges of 772 mA h g−1 while the pristine one, ZIF-8/S8, displayed 502 mA h g−1. The enhanced performance of 54% for ZIF-8/C/S8 indicates that the direct mechanochemical synthesis of ZIF-8 with conductive carbon is beneficial at initials charge/discharge process in comparison to traditional slurry preparation (ZIF-8/S8). Also, the Li2S6 absorption tests shows 87% of discoloration with ZIF-8/C/S8, confirming the better polysulfides absorption. KW - Lithium-sulfur battery KW - Metal organic frameworks KW - ZIF-8 KW - Mechanochemistry PY - 2021 DO - https://doi.org/10.1016/j.jelechem.2021.115459 VL - 896 SP - 115459 PB - Elsevier B.V. AN - OPUS4-53542 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Feiler, Torvid A1 - Bhattacharya, Biswajit A1 - Michalchuk, Adam A1 - Rhim, S.-Y. A1 - Schöder, V. A1 - List-Kratochvil, E. A1 - Emmerling, Franziska T1 - Tuning the mechanical flexibility of organic molecular crystals by polymorphism for flexible optical waveguides JF - CrystEngComm N2 - The ability to selectively tune the optical and the mechanical properties of organic molecular crystals offers a promising approach towards developing flexible optical devices. These functional properties are sensitive to crystallographic packing features and are hence expected to vary with polymorphic modification. Using as a model system the photoluminescent material 4-bromo-6-[(6-chloropyridin-2-ylimino)methyl]phenol (CPMBP), we herein demonstrate the simultaneous tuning of mechanical flexibility and photoluminescence properties via polymorphism. Two new polymorphic forms of CPMBP were obtained from a solution and fully characterised using a combination of experiments and density functional theory simulations. These polymorphic forms exhibit remarkably distinct mechanical properties and an order of magnitude difference in photoluminescence quantum yield. The mechanically plastic form has a higher quantum yield than the brittle polymorphic form. However, their photoluminescence emission profile is largely unaffected by the observed polymorphism, thereby demonstrating that the optical properties and bulk mechanical properties can in principle be tuned independently. By distinguishing between active (involving absorption and emission) and passive (involving no absorption) light propagation, the waveguiding properties of the plastic form of CPMBP (form II) were explored using the straight and bent crystals to highlight the potential applications of CPMBP in designing flexible optical devices. Our results demonstrated that polymorph engineering would be a promising avenue to achieve concurrent modulation of the optical and mechanical properties of photoluminescent molecular crystals for next-generation flexible optical device applications. KW - Mechanochemistry KW - Flexible PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-532075 DO - https://doi.org/10.1039/d1ce00642h VL - 23 IS - 34 SP - 5815 EP - 5825 PB - Royal Society of Chemistry CY - London AN - OPUS4-53207 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Linberg, Kevin A1 - Röder, Bettina A1 - Al-Sabbagh, Dominik A1 - Emmerling, Franziska A1 - Michalchuk, Adam T1 - Controlling polymorphism in molecular cocrystals by variable temperature ball milling JF - Faraday Discussions N2 - Mechanochemistry offers a unique opportunity to modify and manipulate crystal forms, often providing new products as compared with conventional solution methods. While promising, there is little known about how to control the solid form through mechanochemical means, demanding dedicated investigations. Using a model organic cocrystal system (isonicotinamide:glutaric acid), we here demonstrate that with mechanochemistry, polymorphism can be induced in molecular solids under conditions seemingly different to their conventional thermodynamic (thermal) transition point. Whereas Form II converts to Form I upon heating to 363 K, the same transition can be initiated under ball milling conditions at markedly lower temperatures (348 K). Our results indicate that mechanochemical techniques can help to reduce the energy barriers to solid form transitions, offering new insights into controlling polymorphic forms. Moreover, our results suggest that the nature of mechanochemical transformations could make it difficult to interpret mechanochemical solid form landscapes using conventional equilibrium-based tools. KW - Mechanochemistry KW - Kinetics KW - In situ PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-558878 DO - https://doi.org/10.1039/d2fd00115b SP - 1 EP - 16 PB - Royal Society of Chemistry AN - OPUS4-55887 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mazzeo, P A1 - Lampronti, G A1 - Michalchuk, Adam A1 - Belenguer, A A1 - Bacchi, A A1 - Emmerling, Franziska T1 - Accurate extrinsic and intrinsic peak broadening modelling for time-resolved in situ ball milling reactions via synchrotron powder X-ray diffraction JF - Faraday Discussions N2 - The debate on the mechanisms which underpin mechanochemical reactions via ball mill grinding is still open. Our ability to accurately measure the microstructural (crystal size and microstrain) evolution of materials under milling conditions as well as their phase composition as a function of time is key to the in-depth understanding of the kinetics and driving forces of mechanochemical transformations. Furthermore, all ball milling reactions end with a steady state or milling equilibrium – represented by a specific phase composition and relative microstructure – that does not change as long as the milling conditions are maintained. The use of a standard sample is essential to determine the instrumental contribution to the X-ray powder diffraction (XRPD) peak broadening for time-resolved in situ (TRIS) monitoring of mechanochemical reactions under in operando conditions. Using TRIS-XRPD on a ball milling setup, coupled with low-energy synchrotron radiation, we investigated different data acquisition and analysis strategies on a silicon standard powder. The diffraction geometry and the microstructural evolution of the standard itself have been studied to model the instrumental contribution to XRPD peak broadening throughout the grinding activity. Previously proposed functions are here challenged and further developed. Importantly, we show that minor drifts of the jar position do not affect the instrumental resolution function significantly. We here report and discuss the results of such investigations and their application to TRIS-XRPD datasets of inorganic and organic ball mill grinding reactions. KW - Mechanochemistry KW - In situ diffraction KW - Synchrotron radiation KW - Sustainable chemisry PY - 2022 DO - https://doi.org/10.1039/d2fd00104g SP - 1 EP - 17 PB - Royal Society of Chemistry AN - OPUS4-55932 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rautenberg, Max A1 - Bhattacharya, Biswajit A1 - Das, Chayanika A1 - Emmerling, Franziska T1 - Mechanochemical Synthesis of Phosphonate-Based Proton Conducting Metal-Organic Frameworks JF - Inorganic Chemistry N2 - Water-stable metal−organic frameworks (MOFs) with proton-conducting behavior have attracted great attention as promising materials for proton-exchange membrane fuel cells. Herein, we report the mechanochemical gram-scale synthesis of three new mixed-ligand phosphonate-based MOFs, {Co(H2PhDPA)(4,4′-bipy)H2O)·2H2O}n (BAM-1), {Fe(H2PhDPA)(4,4′-bipy) (H2O)·2H2O}n (BAM-2), and {Cu(H2PhDPA)(dpe)2(H2O)2·2H2O}n (BAM-3) [where H2PhDPA = phenylene diphosphonate, 4,4′-bipy = 4,4′-bipyridine, and dpe = 1,2-di(4-pyridyl)ethylene]. Single-crystal X-ray diffraction measurements revealed that BAM-1 and BAM-2 are isostructural and possess a three-dimensional (3D) network structure comprising one-dimensional (1D) channels filled with guest water molecules. Instead, BAM-3 displays a 1D network structure extended into a 3D supramolecular structure through hydrogenbonding and π−π interactions. In all three structures, guest water molecules are interconnected with the uncoordinated acidic hydroxyl groups of the phosphonate moieties and coordinated water molecules by means of extended hydrogen-bonding interactions. BAM-1 and BAM-2 showed a gradual increase in proton conductivity with increasing temperature and reached 4.9 × 10−5 and 4.4 × 10−5 S cm−1 at 90 °C and 98% relative humidity (RH). The highest proton conductivity recorded for BAM-3 was 1.4 × 10−5 S cm−1 at 50 °C and 98% RH. Upon further heating, BAM-3 undergoes dehydration followed by a phase transition to another crystalline form which largely affects its performance. All compounds exhibited a proton hopping (Grotthuss model) mechanism, as suggested by their low activation energy. KW - Mechanochemistry KW - Metal-organic-frameworks KW - Proton conductivity PY - 2022 DO - https://doi.org/10.1021/acs.inorgchem.2c01023 VL - 61 SP - 10801 EP - 10809 PB - ACS Publications AN - OPUS4-55448 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Cocrystal polymorphs & Mechanochemistry - Mechanism & Kinetics N2 - Mechanochemistry is an effective, environmentally benign, and facile method for the synthesis of new crystal forms. Different milling parameters are known to affect the mechanisms and rates of product formation: milling frequency, milling time, filling degree of the milling jar, ball diameter and vessel size, degree of milling ball filling, and material of jars. The increasing interest in mechanochemistry is contrasted by a limited mechanistic understanding of mechanochemical reactivity and selectivity. Control over ball milling transformations is needed before the transformative potential of mechanochemical processing can be realized. Different analytical methods and their combinations have been developed for the time-resolved in situ monitoring of mechanochemical transformations, including powder X-ray diffraction, X-ray absorption spectroscopy, NMR, Raman spectroscopy, and thermography. Here we will discuss our recent results investigating the formation of polymorphic cocrystals thereby elucidating the influence of milling parameters (solvent, temperature, time) and reaction sequences on the formation mechanism and kinetics. For the mechanochemical chlorination reaction of hydantoin normalizing the kinetic profiles to the volume of the milling ball showed clearly that milling reaction kinetics are conserved. Here physical kinetics dominate reaction rates in a ball-milling transformation. Attempting to interpret such kinetics in purely chemical terms risk misinterpreting the results. Our results indicate that time-resolved in situ investigations of milling reactions offer a new approach to tune and optimize mechanochemical processes. T2 - 33th European Crrystallography Meeting CY - Versailles, France DA - 23.08.2022 KW - Mechanochemistry KW - Cocrystals KW - Kinetics KW - Polymorphs PY - 2022 AN - OPUS4-55586 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Cocrystal polymorphs & Mechanochemistry - Mechanism & Kinetics N2 - Mechanochemistry is an effective, environmentally benign, and facile method for the synthesis of new crystal forms. Different milling parameters are known to affect the mechanisms and rates of product formation: milling frequency, milling time, filling degree of the milling jar, ball diameter and vessel size, degree of milling ball filling, and material of jars. The increasing interest in mechanochemistry is contrasted by a limited mechanistic understanding of mechanochemical reactivity and selectivity. Control over ball milling transformations is needed before the transformative potential of mechanochemical processing can be realized. Different analytical methods and their combinations have been developed for the time-resolved in situ monitoring of mechanochemical transformations, including powder X-ray diffraction, X-ray absorption spectroscopy, NMR, Raman spectroscopy, and thermography. Here we will discuss our recent results investigating the formation of polymorphic cocrystals thereby elucidating the influence of milling parameters (solvent, temperature, time) and reaction sequences on the formation mechanism and kinetics. For the mechanochemical chlorination reaction of hydantoin normalizing the kinetic profiles to the volume of the milling ball showed clearly that milling reaction kinetics are conserved. Here physical kinetics dominate reaction rates in a ball-milling transformation. Attempting to interpret such kinetics in purely chemical terms risk misinterpreting the results. Our results indicate that time-resolved in situ investigations of milling reactions offer a new approach to tune and optimize mechanochemical processes. T2 - 3rd CEFMC meeting CY - Kashmir, India DA - 31.08.2022 KW - Mechanochemistry KW - Crystal Engeneering PY - 2022 AN - OPUS4-55641 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Mechanochemical formation of multicomponent crystal systems: Mechanism & Kinetics N2 - Mechanochemistry is an effective, environmentally benign, and facile method for the synthesis of new multicomponent crystal systems. Different milling parameters are known to affect the mechanisms and rates of product formation: milling frequency, milling time, filling degree of the milling jar, ball diameter and vessel size, degree of milling ball filling, and material of jars. The increasing interest in mechanochemistry is contrasted by a limited mechanistic understanding of the mechanochemical reactivity and selectivity. Different analytical methods and their combinations have been developed for the time resolved in situ monitoring of mechanochemical transformations, including powder X-ray diffraction, X-ray adsorption spectroscopy, NMR, Raman spectroscopy, and thermography. Here we will discuss our recent results investigating the formation of (poly-morphic) cocrystals, metal-organic compounds, and salts, thereby elucidating the influence of milling parameters and reaction sequences on the formation mechanism and kinetics. For the mechanochemical chlorination reaction of hydantoin normalizing the kinetic profiles to the volume of the milling ball showed clearly that milling reaction kinetics are conserved. Here physical kinetics dominate reaction rates in a ball-milling transformation. Attempting to interpret such kinetics in purely chemical terms risk misinterpreting the results. Our results indicate that time-resolved in situ investigation of milling reactions offer a new approach to tune and optimize mechanochemical processes. T2 - 25th International Conference on the Chemistry of the Organic Solid State (ICCOSS XXV) CY - Ohrid, Macedonia DA - 03.07.2022 KW - Mechanochemistry KW - In situ real-time monitoring KW - Crystal Engineering PY - 2022 AN - OPUS4-55413 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Mechanochemical formation of multicomponent crystals systems N2 - Mechanochemistry is an effective, environmentally benign, and facile method for the synthesis of new multicomponent crystal systems. Different milling parameters are known to affect the mechanisms and rates of product formation: milling frequency, milling time, filling degree of the milling jar, ball diameter and vessel size, degree of milling ball filling, and material of jars. The increasing interest in mechanochemistry is contrasted by a limited mechanistic understanding of mechanochemical reactivity and selectivity. Different analytical methods and their combinations have been developed for the time-resolved in situ monitoring of mechanochemical transformations, including powder X-ray diffraction, X-ray absorption spectroscopy, NMR, Raman spectroscopy, and thermography. Here we will discuss our recent results investigating the formation of (polymorphic) cocrystals, metal-organic compounds, and salts, thereby elucidating the influence of milling parameters and reaction sequences on the formation mechanism and kinetics. Our results indicate that time-resolved in situ investigations of milling reactions offer a new approach to tune and optimize mechanochemical processes. T2 - 5ECQUL Forging Bonds CY - Lisbon, Portugal DA - 12.07.2022 KW - Mechanochemistry KW - In situ real-time monitoring KW - N-Chlorination PY - 2022 AN - OPUS4-55414 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Shaken not stirred: enhancing the flavor of mechanochemistry N2 - compounds and cocrystals. The ever-increasing interest in this method is contrasted by a limited mechanistic understanding of the mechanochemical reactivity and selectivity. Different milling parameters are known to affect the mechanisms and rates of product formation: milling frequency, milling time, filling degree of the milling jar, ball diameter and vessel size, degree of milling ball filling, and material of jars. Time-resolved in situ investigations of milling reactions (Figure 1) provide direct insights into the underlying mechanisms. We recently introduced different setups enabling in situ investigation of mechanochemical reactions using synchrotron XRD and XAS combined with Raman spectroscopy and thermography. The presented setup allows the detection of crystalline, amorphous, eutectic, and liquid intermediates. Furthermore, the chemical composition of the reaction mixture was found to be directly correlated with changes in the temperature profile of the reaction. The resulting deeper kinetic and thermodynamic understanding of milling processes is the key to future optimization of mechanochemical syntheses. In this contribution, we will discuss our recent results investigating the formation of (polymorphic) cocrystals and coordination polymers. Our results indicate that time-resolved in situ investigations of mechanochemical processes are key for tuning and optimizing mechanochemical syntheses allowing to unleash the potential of mechanochemistry for a green materials design. T2 - 2nd National Crystallographic Meeting Lisbon, Portugal CY - Lisbon, Portugal DA - 15.07.2022 KW - Mechanochemistry KW - In situ real-time monitoring KW - Crystal PY - 2022 AN - OPUS4-55415 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Mechanochemical formation of multicomponent crystal systems: Mechanism & Kinetics N2 - Mechanochemistry is an effective, environmentally benign, and facile method for the synthesis of new multicomponent crystal systems. Different milling parameters are known to affect the mechanisms and rates of product formation: milling frequency, milling time, filling degree of the milling jar, ball diameter and vessel size, degree of milling ball filling, and material of jars. The increasing interest in mechanochemistry is contrasted by a limited mechanistic understanding of the mechanochemical reactivity and selectivity. Different analytical methods and their combinations have been developed for the time resolved in situ monitoring of mechanochemical transformations, including powder X-ray diffraction, X-ray adsorption spectroscopy, NMR, Raman spectroscopy, and thermography.1 Here we will discuss our recent results investigating the formation of (polymorphic) cocrystals2–3 and metal-organic frameworks,4 thereby elucidating the influence of milling parameters and reaction sequences on the formation mechanism and kinetics. For the mechanochemical chlorination reaction of hydantoin normalizing the kinetic profiles to the volume of the milling ball showed clearly that milling reaction kinetics are conserved.6 Here physical kinetics dominate reaction rates in a ball-milling transformation. Attempting to interpret such kinetics in purely chemical terms risk misinterpreting the results. Our results indicate that time-resolved in situ investigation of milling reactions offer a new approach to tune and optimize mechanochemical processes. T2 - 10th International conference on Mechanochemistry and Mechanical Alloying CY - Cagliari, Italy DA - 06.06.2022 KW - Mechanochemistry KW - In situ real-time monitoring KW - Cocrystal PY - 2022 AN - OPUS4-55421 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rautenberg, Max A1 - Bhattacharya, Biswajit A1 - Witt, Julia A1 - Jain, Mohit A1 - Emmerling, Franziska T1 - In situ time-resolved monitoring of mixed-ligand metal–organic framework mechanosynthesis JF - CrystEngComm N2 - The mechanism of mixed-ligand metal–organic framework (MOF) formation, and the possible role of intermediate single-ligand metal complexes during mechanosynthesis, have not been explored yet. For the first time, we report here in situ real-time monitoring of the mechanochemical formation mechanism of mixed-ligand MOFs. Our results show that binary phases can act as intermediates or competing products in one-pot and stepwise synthesis. KW - Mechanochemistry KW - Metal-organic-frameworks KW - In situ X-ray diffraction KW - Mixed-ligand MOFs PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-558167 DO - https://doi.org/10.1039/D2CE00803C SP - 1 EP - 4 PB - Royal Society of Chemistry AN - OPUS4-55816 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 JF - Crystal Growth & Design 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 - Kulla, Hannes A1 - Haferkamp, Sebastian A1 - Akhmetova, Irina A1 - Röllig, Mathias A1 - Maierhofer, Christiane A1 - Rademann, Klaus A1 - Emmerling, Franziska T1 - In situ investigations of mechanochemical one-pot syntheses JF - Angewandte Chemie International Edition N2 - We present an in situ triple coupling of synchrotron X-ray diffraction with Raman spectroscopy, and thermography to study milling reactions in real time. This combination of methods allows a correlation of the structural evolution with temperature information. The temperature information is crucial for understanding both the thermodynamics and reaction kinetics. The reaction mechanisms of three prototypical mechanochemical syntheses, a cocrystal formation, a C@C bond formation (Knoevenagel condensation), and the formation of a manganese-phosphonate, were elucidated. Trends in the temperature development during milling are identified. The heat of reaction and latent heat of crystallization of the product contribute to the overall temperature increase. A decrease in temperature occurs via release of, for example, water as a byproduct. Solid and liquid intermediates are detected. The influence of the mechanical impact could be separated from temperature effects caused by the reaction. KW - In situ studies KW - Mechanochemistry KW - Raman spectroscopy KW - Thermography KW - X-ray diffraction PY - 2018 DO - https://doi.org/10.1002/anie.201800147 SN - 1433-7851 SN - 1521-3773 VL - 57 IS - 20 SP - 5930 EP - 5933 PB - Wiley-VCH CY - Weinheim AN - OPUS4-44946 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Al-Terkawi, Abdal-Azim A1 - Scholz, G. A1 - Prinz, Carsten A1 - Zimathies, Annett A1 - Emmerling, Franziska A1 - Kemnitz, E. T1 - Hydrated and dehydrated Ca-coordination polymers based on benzene-dicarboxylates: mechanochemical synthesis, structure refinement, and spectroscopic characterization JF - CrystEngComm N2 - A series of Ca-based coordination polymers were prepared mechanochemically by milling Ca(OH)2 with phthalic acid (H2oBDC), isophthalic acid (H2mBDC), and terephthalic acid (H2pBDC). The hydrated compounds [Ca(oBDC)(H2O)], [Ca(mBDC)(H2O)3.4], and [Ca(pBDC)(H2O)3] were prepared for the first time via mechanochemical routes. The refined structures were validated by extended X-ray absorption data. The new dehydrated compound [Ca(oBDC)] (1-H2O), obtained after the thermal post-treatment of 1 in a reversible phase transition process, was determined ab initio based on the powder X-ray diffraction (PXRD) data. The materials were thoroughly characterized using elemental analysis, thermal analysis, and spectroscopic methods: magic-angle spinning NMR and attenuated total reflection-infrared spectroscopy. The specific surface areas and sorption properties of the hydrated and dehydrated samples were determined using the isotherms of gas sorption and dynamic vapor sorption measurements. KW - Mechanochemistry KW - XRD PY - 2018 UR - http://pubs.rsc.org/en/content/articlehtml/2017/ce/c7ce01906h DO - https://doi.org/10.1039/C7CE01906H VL - 20 SP - 946 EP - 961 PB - Royal Society of Chemistry AN - OPUS4-44440 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Al-Terkawi, Abdal-Azim A1 - Scholz, Gudrun A1 - Emmerling, Franziska A1 - Kemnitz, Erhard T1 - Ca-Tetrafluorophthalate and Sr-isophthalate: mechanochemical synthesis and characterization in comparison with other Ca-and Sr-coordination polymers JF - Dalton Transactions N2 - New Ca- and Sr-based coordination polymers (CPs) were mechanochemically synthesized by milling metal hydroxide samples (M = Ca, Sr) with tetrafluorophthalic acid (H2oBDC-F4) and isophthalic acid (H2mBDC). [Ca(oBDC-F4)(H2O)2] (1) exhibits a small surface area which is slightly increased after removing the crystal water. On the other hand, the hydrated sample of the nonfluorinated [Sr(mBDC)(H2O)3.4] (2) reveals a small BET surface area which remains unchanged even after the release of crystal water via thermal treatment. The new compounds 1 and 2 are similar to their Sr- and Ca-analogs, respectively. These findings are confirmed by thermal analysis, MAS NMR, and ATR-IR measurements, in addition to the Le Bail refinements for the measured powder X-ray data of 1 and 2. Ca- and Sr-CPs based on perfluorinated dicarboxylic systems and their nonfluorinated analogs diverse in structural and chemical properties depending on the geometries of the organic linkers and the presence of fluorine atoms. The fluorinations of organic ligands lead to the formation of fluorinated CPs with higher dimensionalities compared to their nonfluorinated counterparts. Conversely, the thermal stabilities of the latter are higher than those of the fluorinated CPs. KW - Mechanochemistry PY - 2018 DO - https://doi.org/10.1039/c8dt00695d SN - 1477-9226 SN - 1477-9234 VL - 47 IS - 16 SP - 5743 EP - 5754 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-44696 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Emmerling, Franziska A1 - Haferkamp, Sebastian A1 - Kraus, Werner T1 - Studies on the mechanochemical Knoevenagel condensation of fluorinated benzaldehyde derivates JF - Journal of Materials Science N2 - The mechanochemical Knoevenagel condensation of three fluorinated benzaldehyde derivates and malononitrile was investigated. The reactions were performed under solvent- and catalyst-free conditions and resulted in highly crystalline products after crystallization from a viscous phase in the milling jar. The quality of the obtained crystals was sufficient for single-crystal X-ray diffraction circumventing a recrystallization step. To gain more information on the reaction, progress was investigated in situ using time-resolved Raman spectroscopy. The results show a direct conversion of the reactants. KW - C-C coupling KW - Knoevenagel condensation KW - In situ KW - Mechanochemistry PY - 2018 DO - https://doi.org/10.1007/s10853-018-2492-0 SN - 0022-2461 VL - 53 IS - 19 SP - 13713 EP - 13718 PB - Springer Link AN - OPUS4-45682 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 JF - Solid State Nuclear Magnetic Resonance 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 - CONF A1 - Emmerling, Franziska T1 - New insights in cocrystal formations: in situ investigations of mechanochemical syntheses N2 - Mechanochemistry is increasingly used for synthesizing soft matter materials including metal organic compounds and cocrystals. The ever-increasing interest in this method is contrasted by a limited mechanistic understanding of the mechanochemical reactivity and selectivity. Time-resolved in situ investigations of milling reactions provide direct insights in the underlying mechanisms. We introduced a setup enabling in situ investigation of mechanochemical reactions using synchrotron XRD combined with Raman spectroscopy. The specific combination allows to study milling processes comprehensively on the level of the molecular and crystalline structure and thus obtaining reliable data for mechanistic studies. We discuss our recent results investigating the formation of (polymorphic) cocrystals. First investigations of a mechanochemical synthesis under controlled temperature which allow determining the activation barrier are presented.6 Furthermore, X-ray diffraction and in situ Raman spectroscopy coupled with thermography revealed a low temperature increase during milling reactions due to the mechanical impact and clear temperature increases as a result of the reaction heat. Our results indicate that in situ investigation of milling reactions offer a new approach to tune and optimize mechanochemically synthesized compounds. T2 - CSEC Seminar University of Edinburgh CY - Edinburgh, Scotland DA - 16.05.2019 KW - Mechanochemistry KW - Acoustic levitation KW - In situ PY - 2019 AN - OPUS4-48098 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 JF - Beilstein Journal of Organic Chemistry 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 - de Oliveira, P. F. M. A1 - Torresi, R. A1 - Emmerling, Franziska A1 - Carmago, P. T1 - Challenges and opportunities in the bottom-up mechanochemical synthesis of noble metal nanoparticles JF - Journal of Materials Chemistry A N2 - Mechanochemistry is a promising alternative to solution-based protocols across the chemical sciences, enabling different types of chemistries in solvent-free and environmentally benign conditions. The use of mechanical energy to promote physical and chemical transformations has reached a high level of refinement, allowing for the design of sophisticated molecules and nanostructured materials. Among them, the synthesis of noble metal nanoparticles deserves special attention due to their catalytic applications. In this review, we discuss the recent progress on the development of mechanochemical strategies for the controlled synthesis of noble metal nanostructures. We start by covering the fundamentals of different preparation routes, namely top-down and bottom-up approaches. Next, we focus on the key examples of the mechanochemical synthesis of non-supported and supported metal nanoparticles as well as hybrid nanomaterials containing noble metals. In these examples, in addition to the principles and synthesis mechanisms, their performances in catalysis are discussed. Finally, a perspective of the field is given, where we discuss the opportunities for future work and the challenges of mechanochemical synthesis to produce well-defined noble metal nanoparticles. KW - Mechanochemistry KW - Nanoparticles PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-512080 DO - https://doi.org/10.1039/D0TA05183G VL - 8 IS - 32 SP - 16114 AN - OPUS4-51208 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rautenberg, Max A1 - Bhattacharya, Biswajit A1 - Akhmetova, Irinia A1 - Emmerling, Franziska T1 - Mechanochemical and solution syntheses of two novel cocrystals of orcinol with two N,N0-Dipyridines: Structural diversity with varying ligand flexibility JF - Journal of Molecular Structure N2 - We studied the influence of coformers flexibility on the supramolecular assembly of 5-substituted resorcinol. Two cocrystals of orcinol (ORL) with two dipyridine molecules, i.e. 1,2-di(4-pyridyl)ethane (ORLeBPE) and 1,2-di(4-pyridyl)ethylene (ORLeBPY), were prepared by mechanochemical synthesis and slow evaporation of solvent. The new crystalline solids were thoroughly characterized by single crystal Xray diffraction (SCXRD), powder X-ray diffraction analysis (PXRD), Fourier-transform infrared spectroscopy (FT-IR), differential thermal analysis (DTA), and thermogravimetric analysis (TGA). Structural determination reveals that in both cocrystals, the phenolepyridine, i.e. OeH/N(py) heterosynthon takes the main role in the formation of cocrystals. In ORLeBPE, the components form infinite 1D zig-zag chains, which are extended to 2D layer structure by inter-chain CeH/O interactions between BPE hydrogen atoms and hydroxyl oxygen atoms of ORL. In ORLeBPY, the components form a 0D fourcomponent complex. Formation of the discrete assemblies is attributed to the comparative rigid nature of BPY, which restricts the formation of an extended network. KW - Cocrystal KW - Single crystal KW - X-ray diffraction KW - Mechanochemistry PY - 2020 DO - https://doi.org/10.1016/j.molstruc.2020.128303 SN - 0022-2860 VL - 1217 SP - 128303 PB - Elsevier B.V. AN - OPUS4-51023 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zänker, Steffen A1 - Scholz, G. A1 - Heise, M. A1 - Kemnitz, E. A1 - Emmerling, Franziska T1 - New 2D layered structures with direct fluorine-metal bonds: MF(CH3COO) (M: Sr, Ba, Pb) JF - CrystEngComm N2 - New coordination polymers with 2D network structures with fluorine directly coordinated to the metal ion were prepared both via mechanochemical synthesis and fluorolytic sol–gel synthesis. Depending on the synthesis route, the samples show different particle sizes, according to SEM imaging. The crystal structures of barium acetate fluoride, strontium acetate fluoride, and lead acetate fluoride (BaFIJCH3COO), SrFIJCH3COO) and PbFIJCH3COO)) were solved from X-ray powder diffraction data. The structure solution is backed by the results from 19F MAS NMR, FT IR data, and thermal analysis. The calculated chemical shifts of the 19F MAS NMR spectra coincide well with the measured ones. It turns out that the grinding conditions have a remarkable influence on the mechanochemical synthesis and its products. Our systematic study also indicates a strong influence of the atomic radii of Ca, Sr, Ba, and Pb on the success of the syntheses. KW - Mechanochemistry KW - Coordination polymers PY - 2020 DO - https://doi.org/10.1039/d0ce00287a VL - 22 IS - 16 SP - 2772 EP - 2780 PB - Royal Society of Chemistry AN - OPUS4-50789 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Haferkamp, Sebastian A1 - Emmerling, Franziska A1 - Akhmetova, Irina A1 - Kulla, Hannes A1 - Rademann, K. T1 - Insights into the mechanochemical Knoevenagel condensation N2 - Mechanochemistry paves the way to simple, fast, and green syntheses, but there is a lack in understanding of the underlying mechanisms. Here, we present a universal strategy for simultaneous real-time in situ analysis, combining X-ray diffraction, Raman spectroscopy, and thermography. T2 - Bessy User Meeting 2019 CY - Berlin, Germany DA - 05.12.2019 KW - Mechanochemistry PY - 2019 AN - OPUS4-50122 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Ein Blick in die Welt der Mechanochemie N2 - Perhaps due in no small part to its historical mystique, mechanochemistry has been shrowded in relative obscurity for quite some time. The successes of mechanochemistry in organic synthesis have often been curtailed by a fundamentally limited mechanistic understanding. Lately, however, the community has made great strides towards understanding the fundamentals, as well as large steps forward regarding industrially significant scale-up via twin-screw extrusion. A variety of recent work has traded in some of mechanochemistry’s mystique for simple, straight-forward chemical guidelines. T2 - Seminar Anorganische Chemie Universität Kiel CY - Kiel, Germany DA - 22.10.19 KW - Mechanochemistry KW - XRD PY - 2019 AN - OPUS4-50134 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - May the force be with you - in situ investigation of mechanochemical reactions N2 - The past decade has seen a reawakening of solid-state to chemical synthesis, driven by the search for new, cleaner synthetic methodologies. Mechanochemistry has advanced to a widely applicable technique. T2 - SALSA's "Make and Measure 2019 CY - Berlin, Germany DA - 25.10.2019 KW - Mechanochemistry KW - Metal–organic frameworks PY - 2019 AN - OPUS4-50138 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Mechanochemistrry - a time resolved perspective on unconventional crystallization N2 - Green chemsistry apporoach for the synthesis of metal organic frameworks. T2 - IFW BAM Workshop CY - Berlin, Germany DA - 25.11.2019 KW - Mechanochemistry KW - XRD KW - Metal-organic-frameworks PY - 2019 AN - OPUS4-50110 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Linberg, Kevin A1 - Ali, Naveed Zafar A1 - Etter, M. A1 - Michalchuk, Adam A1 - Rademann, K. A1 - Emmerling, Franziska T1 - A Comparative Study of the Ionic Cocrystals NaX (α-d-Glucose)2 (X = Cl, Br, I) JF - Crystal growth & design N2 - The mechanochemical formation of the ionic cocrystals of glucose (Glc) and sodium salts Glc2NaCl·H2O (1) and Glc2NaX (X = Br (2), I (3)) is presented. Products are formed by co-milling Glc with three sodium salts (NaCl, NaBr, NaI). The ionic cocrystals were obtained under both neat grinding and liquid-assisted grinding conditions, the later found to accelerate the reaction kinetics. The crystal structures of the ionic cocrystals (2) and (3) were solved from powder X-ray diffraction data. The structure solution contrasts with the structure of Glc2NaCl·H2O (1) where the electron density at three halide crystallographic sites is modeled as of being the intermediate between water molecule and a chloride ion. The reaction pathways of the three ionic cocrystals were investigated in real time using our tandem approach comprising a combination of in situ synchrotron powder X-ray diffraction and Raman spectroscopy. The results indicate the rapid formation of each cocrystal directly from their respective starting materials without any intermediate moiety formation. The products were further characterized by DTA-TG and elemental analysis. KW - In situ KW - Co-crystal KW - Mechanochemistry KW - Glucose PY - 2019 DO - https://doi.org/10.1021/acs.cgd.8b01929 VL - 19 IS - 8 SP - 4293 EP - 4299 PB - ACS Publications AN - OPUS4-48781 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stroh, Julia A1 - Feiler, Torvid A1 - Ali, N. Z. A1 - Minas da Piedade, M. E. A1 - Emmerling, Franziska T1 - Mechanistic Insights into a Sustainable Mechanochemical Synthesis of Ettringite JF - ChemistryOpen N2 - Mechanochemistry offers an environmentally benign and facile synthesis method for a variety of cement paste constituents. In addition, these methods can be used to selectively tune the properties of cement components. The mineral ettringite is an important component of cementitious materials and has additional technological potential due to its ion exchange properties. Synthesis of ettringite via mechanochemistry is an environmentally friendly alternative to conventional wet-chemical synthesis established in industry. This contribution explores the mechanism of a two-step mechanochemical synthesis of ettringite, which was previously found to greatly improve the reaction conversion as compared with one-pot synthesis. The crystallinity of Al(OH)3 was found to decrease during the first stage of this mechanochemical synthesis. This was correlated to a significant decrease in the particle size of Al(OH)3 in this stage. No other significant changes were found for the other components, suggesting that mechanochemical activation of Al(OH)3 is responsible for the enhanced formation of ettringite by the two-step approach. The environmentally friendly approach developed for ettringite synthesis offers a versatile synthetic strategy, which can be applied to synthesise further cementitious materials. KW - Ettringite KW - Mechanochemistry KW - Sustainability KW - X-ray diffraction PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-489172 DO - https://doi.org/10.1002/open.201900215 VL - 8 IS - 7 SP - 1012 EP - 1019 PB - ChemPubSoc AN - OPUS4-48917 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 JF - ChemComm 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 - Al-Terkawi, Abdal-Azim A1 - Prinz, Carsten A1 - Scholz, Gudrun A1 - Kemnitz, Erhard A1 - Emmerling, Franziska T1 - Ca-, Sr-, and Ba-Coordination polymers based on anthranilic acid via mechanochemistry JF - Daltron Transaction N2 - Ca-, Sr-, and Ba-Based coordination polymers (CPs) were prepared mechanochemically by milling metal-hydroxide samples with anthranilic acid (oABAH). {[Ca(oABA)2(H2O)3]}n consists of one-dimensional polymeric chains that are further connected by a hydrogen-bonding network. {[Sr(oABA)2(H2O)2]·H2O}n is a one-dimensional CP in which water molecules bridge Sr2+ ions and increase the dimensionality by building an extended network. {[Ba(oABA)2(H2O)]}n crystallizes as a two-dimensional CP comprising one bridging water molecule. The cation radii influence the inorganic connectivity and dimensionality of the resulting crystal structures. The crystal structures were refined from powder X-ray diffraction data using the Rietveld method. The local coordination environments were studied via extended X-ray absorption fine structure (EXAFS) measurements. The compounds were further characterized using comprehensive analytical methods such as elemental analysis, thermal analysis, MAS NMR, imaging, and dynamic vapor sorption (DVS) measurements. Compounds 1, 2, and 3 exhibit small surface areas which decrease further after thermal annealing experiments. All compounds exhibit a phase transformation upon heating, which is only reversible in 3. KW - Mechanochemistry KW - XRD PY - 2019 DO - https://doi.org/10.1039/c9dt00991d SN - 1477-9226 SN - 1477-9234 VL - 48 IS - 19 SP - 6513 EP - 6521 PB - Royal Society of Chemistry AN - OPUS4-48014 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Surov, A. A1 - Vasilev, N. A1 - Voronin, A. A1 - Churakov, A. A1 - Emmerling, Franziska A1 - Perlovich, G. T1 - Ciprofloxacin salts with benzoic acid derivatives: structural aspects, solid-state properties and solubility performance JF - Crystengcomm N2 - n this work, three new pharmaceutical hydrated salts of ciprofloxacin with selected derivatives of benzoic acid, namely 4-hydroxybenzoic acid, 4-aminobenzoic acid and gallic acid, were obtained and systematically investigated by several solid-state analytical techniques. In situ Raman spectroscopy was applied to elucidate the alternative pathways of the solid forms' formation under mechanochemical conditions. Crystal structure analysis and a CSD survey allowed us to establish a distinct supramolecular motif formed by infinite columnar stacks of ciprofloxacin dimers arranged in the “head-to-tail” manner. An alternative “head-to-head” packing arrangement was only observed in the crystal of the hydrated ciprofloxacin salt with 4-aminobenzoic acid. In addition, the pH-solubility behavior of the solid forms was thoroughly investigated. Furthermore, a distinct structure–property relationship between the specific features of the supramolecular organization of the hydrated salts and their solubility was observed and discussed. KW - Mechanochemistry KW - XRD PY - 2020 DO - https://doi.org/10.1039/D0CE00514B VL - 22 IS - 25 SP - 4238 EP - 4249 AN - OPUS4-51818 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Opitz, P. A1 - Asta, M. A1 - Fernandez-Martinez, A. A1 - Panthöfer, M. A1 - Kabelitz, Anke A1 - Emmerling, Franziska A1 - Mondeshki, M. A1 - Tremel, W. T1 - Monitoring a Mechanochemical Syntheses of Isostructural Luminescent Cocrystals of 9-Anthracenecarboxylic Acid with two Dipyridines Coformers JF - Crystal Growth and Design N2 - Amorphous calcium carbonate (ACC) is an important precursor in the biomineralization of crystalline CaCO3. In nature, it serves as a storage material or as a permanent structural element, whose lifetime is regulated by an organic matrix. The relevance of ACC in materials science is primarily related to our understanding of CaCO3 crystallization pathways and CaCO3/(bio)polymer nanocomposites. ACC can be synthesized by liquid–liquid phase separation, and it is typically stabilized with macromolecules. We have prepared ACC by milling calcite in a planetary ball mill. Phosphate “impurities” were added in the form of monetite (CaHPO4) to substitute the carbonate anions, thereby stabilizing ACC by substitutional disorder. The phosphate anions do not simply replace the carbonate anions. They undergo shear-driven acid/base and condensation reactions, where stoichiometric (10%) phosphate contents are required for the amorphization to be complete. The phosphate anions generate a strained network that hinders ACC recrystallization kinetically. The amorphization reaction and the structure of BM-ACC were studied by quantitative Fourier transform infrared spectroscopy and solid state 31P, 13C, and 1H magic angle spinning nuclear magnetic resonance spectroscopy, which are highly sensitive to symmetry changes of the local environment. In the first—and fast—reaction step, the CO32– anions are protonated by the HPO42– groups. The formation of unprecedented hydrogen carbonate (HCO3–) and orthophosphate anions appears to be the driving force of the reaction, because the phosphate group has a higher Coulomb energy and the tetrahedral PO43– unit can fill space more efficiently. In a competing second—and slow—reaction step, pyrophosphate anions are formed in a condensation reaction. No pyrophosphates are formed at higher carbonate contents. High strain leads to such a large energy barrier that any reaction is suppressed. Our findings aid in the understanding of the mechanochemical amorphization of calcium carbonate and emphasize the effect of impurities for the stabilization of the amorphous phases in general. Our approach allowed the synthesis of new amorphous alkaline earth defect variants containing the unique HCO3– anion. Our approach outlines a general strategy to obtain new amorphous solids for a variety of carbonate/phosphate systems that offer promise as biomaterials for bone regeneration. KW - Crystallization KW - Mechanochemistry KW - PDF PY - 2020 DO - https://doi.org/10.1021/acs.cgd.0c00912 VL - 20 IS - 10 SP - 6831 EP - 6846 PB - American Chemical Society AN - OPUS4-51819 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - de Olivera, Paulo A1 - Michalchuk, Adam A1 - Marquardt, Julien A1 - Feiler, Torvid A1 - Prinz, Carsten A1 - Torresi, R. A1 - Camargo, P. A1 - Emmerling, Franziska T1 - Investigating the role of reducing agents on mechanosynthesis of Au nanoparticles JF - CrystEngComm N2 - Control over the bottom up synthesis of metal nanoparticles (NP) depends on many experimental factors, including the choice of stabilising and reducing agents. By selectively manipulating these species, it is possible to control NP characteristics through solution-phase synthesis strategies. It is not known, however, whether NPs produced from mechanochemical syntheses are governed by the same rules. Using the Au NPs mechanosynthesis as a model system, we investigate how a series of common reducing agents affect both the reduction kinetics and size of Au NPs. It is shown that the relative effects of reducing agents on mechanochemical NP synthesis differ significantly from their role in analogous solution-phase reactions. Hence, strategies developed for control over NP growth in solution are not directly transferrable to environmentally benign mechanochemical approaches. This work demonstrates a clear need for dedicated, systematic studies on NP mechanosynthesis. KW - Mechanochemistry KW - Metal nanoparicels PY - 2020 DO - https://doi.org/10.1039/d0ce00826e VL - 22 IS - 38 SP - 6261 EP - 6267 PB - Royal Society of Chemistry AN - OPUS4-51757 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -