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 - Chewle, Surahit A1 - Emmerling, Franziska A1 - Weber, M. T1 - Effect of choice of solvent on crystallization pathway of paracetamol: An experimental and theoretical case study JF - Crystals N2 - The choice of solvents influences crystalline solid formed during the crystallization of active pharmaceutical ingredients (API). The underlying effects are not always well understood because of the complexity of the systems. Theoretical models are often insufficient to describe this phenomenon. In this study, the crystallization behavior of the model drug paracetamol in different solvents was studied based on experimental and molecular dynamics data. The crystallization process was followed in situ using time-resolved Raman spectroscopy. Molecular dynamics with simulated annealing algorithm was used for an atomistic understanding of the underlying processes. The experimental and theoretical data indicate that paracetamol molecules adopt a particular geometry in a given solvent predefining the crystallization of certain polymorphs KW - Crystallization KW - Nucleation KW - Polymorphism KW - Raman spectroscopy KW - Cassical nucleation theory PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-520052 DO - https://doi.org/10.3390/cryst10121107 SN - 2073-4352 VL - 10 IS - 12 SP - 1 EP - 10 PB - MDPI CY - Basel AN - OPUS4-52005 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 - Joester, Maike A1 - Seifert, Stephan A1 - Emmerling, Franziska A1 - Kneipp, Janina T1 - Physiological influence of silica on germinating pollen as shown by Raman spectroscopy JF - Journal of Biophotonics N2 - The process of silicification in plants and the biochemical effects of silica in plant tissues are largely unknown. To study the molecular changes occurring in growing cells that are exposed to higher than normal concentration of silicic acid, Raman spectra of germinating pollen grains of three species (Pinus nigra, Picea omorika, and Camellia japonica) were analyzed in a multivariate classification approach that takes into account the variation of biochemical composition due to species, plant tissue structure, and germination condition. The results of principal component analyses of the Raman spectra indicate differences in the utilization of stored lipids, a changed mobilization of storage carbohydrates in the pollen grain bodies, and altered composition and/or structure of cellulose of the developing pollen tube cell walls. These biochemical changes vary in the different species. KW - Silica KW - Raman spectroscopy KW - Principal component analysis PY - 2017 DO - https://doi.org/10.1002/jbio.201600011 SN - 1864-063X SN - 1864-0648 VL - 10 IS - 4 SP - 542 EP - 552 AN - OPUS4-40090 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nguyen, Thi Yen A1 - Roessler, Ernst A1 - Rademann, Klaus A1 - Emmerling, Franziska T1 - Control of organic polymorph formation: crystallization pathways in acoustically levitated droplets JF - Zeitschrift für Kristallographie - Crystalline Materials N2 - Theoretical and experimental studies indicate that crystal nucleation can take more complex pathways than expected on the ground of the classical nucleation theory. Among these pathways are the formation of pre-nucleation clusters and amorphous precursor phases. A direct in situ observation of the different pathways of nucleation from solution is challenging since the paths can be influenced by heterogeneous nucleation sites, such as container walls. Here, we provide insights into the crystallization process using the in situ combination of an acoustic levitator, Raman spectroscopy, and X-ray scattering. The contactless sample holder enables the observation of homogeneous crystallization processes and the detection of intermediates and final crystalline forms. We provide evidence for the existence of multiple pathways of nucleation based on the investigation of the crystallization of organic molecules from different solvents. Starting from a diluted solution, a supersaturation is reached during the experiment due to the evaporation of the solvent. The highly supersaturated solution reveals different pathways of crystallization. Depending on the degree of supersaturation either the thermodynamically stable or the metastable crystal form is observed. KW - Crystallization KW - In situ XRD KW - Polymorphism KW - Polyamorphism KW - Raman spectroscopy PY - 2017 DO - https://doi.org/10.1515/zkri-2016-1964 SN - 2194-4946 SN - 2196-7105 VL - 232 IS - 1-3 SP - 15 EP - 24 PB - De Gruyter CY - Berlin AN - OPUS4-39708 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Batzdorf, Lisa A1 - Nguyen, Thi Yen A1 - Rump, Doreen A1 - Emmerling, Franziska T1 - Crystallization behavior of carbamazepine JF - Zeitschrift für physikalische Chemie N2 - Carbamazepine (CBZ) is known for its variety of anhydrous and hydrous polymorphs. Herein, a thorough analysis of the crystallization behavior of CBZ is presented. The influence of the solvent and the concentration on the crystallization behavior under different environmental conditions is investigated by combined in situ XRD and Raman spectroscopy measurements. Crystallization studies conducted via conventional crystallization in glass tubes and in levitated droplets using an acoustic levitator indicate a dependence of the crystallization process from solvent and surface. KW - Carbamazepine KW - Polymorphism KW - Acoustic levitation KW - XRD KW - Raman spectroscopy PY - 2014 DO - https://doi.org/10.1515/zpch-2013-0452 SN - 0942-9352 SN - 2196-7156 SN - 0044-3336 SN - 0044-3328 SN - 0942-9352 N1 - Geburtsname von Batzdorf, Lisa: Tröbs, L. - Birth name of Batzdorf, Lisa: Tröbs, L. VL - 228 IS - 4-5 SP - 493 EP - 501 PB - Oldenbourg CY - München AN - OPUS4-30627 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Batzdorf, Lisa A1 - Emmerling, Franziska T1 - Mechanochemical synthesis and characterisation of cocrystals and metal-organic compounds JF - Faraday discussions N2 - The mechanochemical synthesis of two model compounds, a metal organic framework ([Bi(1,4-bdc)2]*(Im) (bdc = benzene dicarboxylate, Im = imidazole cation)) and a cocrystal (Carbamazepine:Indometacin 1:1) were followed ex situ by combined analytical methods. Powder X-ray diffraction (XRD) and Raman spectroscopy data were evaluated for the synthesis of the metal organic framework. XRD measurements and REM images were analysed for the synthesis of the cocrystal. The measurements revealed that both model compounds were synthesised within minutes. The metal organic framework [Bi(1,4-bdc)2]*(Im) is synthesised via an intermediate structure. The cocrystal Carbamazepine:Indometacin 1:1 is formed within few seconds and afterwards the crystallite size decreases extremely. KW - Powder X-ray diffraction (XRD) KW - Raman spectroscopy KW - mechanochemical synthesis PY - 2014 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-306305 UR - http://pubs.rsc.org/en/content/articlepdf/2014/fd/c3fd00163f DO - https://doi.org/10.1039/C3FD00163F SN - 1359-6640 SN - 1364-5498 N1 - Geburtsname von Batzdorf, Lisa: Tröbs, L. - Birth name of Batzdorf, Lisa: Tröbs, L. SP - 109 EP - 119 PB - RSC CY - Cambridge [u.a.] AN - OPUS4-30630 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gnutzmann, Tanja A1 - Kahlau, R. A1 - Scheifler, S. A1 - Friedrichs, Ferdinand A1 - Rössler, A. A1 - Rademann, Klaus A1 - Emmerling, Franziska T1 - Crystal growth rates and molecular dynamics of nifedipine JF - CrystEngComm N2 - The unusually fast crystallization of the organic compound nifedipine has been investigated in detail using different solutions as precursors for the formation of the initial glassy nifedipine films. Starting from these amorphous films the crystallization process was investigated by time-resolved light microscopy at different temperatures around Tg of nifedipine. In all studied cases (acetone, acetonitrile, ethyl acetate, dichloromethane, tetrahydrofuran) the measured mean crystallization rates are, on average, 10000 times higher than rates reported in previous studies. Such high rates cannot be explained by a classical diffusional crystal growth mechanism of nifedipine. Instead, nifedipine shows a strong propensity for diffusionless growth. Solvent assisted or solvent induced preordering of the glassy modification is suggested to be the most probable driving force behind these fast crystallization processes. The nifedipine crystallization rates can be controlled not only by specific solvent–molecule interactions but also by temperature. Below 40 °C, the temperature dependence of the rates is generally small. Above 40 °C, a slowing down of the crystallization rates with increasing temperatures indicates a kinetic competition between different polymorphs. The molecular dynamics of nifedipine molecules in the amorphous phase as well as the relaxation times are studied by dielectric measurements. The dielectric data corroborate the inherently strong propensity of nifedipine to crystallize diffusionlessly under all conditions. KW - Fast crystallization KW - Diffusionless growth KW - Polymorphism KW - Nifedipine KW - Preordering KW - Raman spectroscopy KW - Dielectric spectroscopy PY - 2013 DO - https://doi.org/10.1039/c2ce26911b SN - 1466-8033 VL - 15 IS - 20 SP - 4017 EP - 4202 CY - London, UK AN - OPUS4-28307 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gnutzmann, Tanja A1 - Rademann, K. A1 - Emmerling, Franziska T1 - Fast crystallization of organic glass formers JF - Chemical communications N2 - An unusually fast crystallization of the organic glass former nifedipine has been observed. The crystallization process, starting from an amorphous film to crystalline material, was investigated by time resolved Raman microspectroscopy. The crystallization rates of the initially crystallizing metastable β-form are four orders of magnitude higher than those of previous studies. KW - Polymorphism KW - Raman spectroscopy KW - Crystallization KW - Nifedipine PY - 2012 DO - https://doi.org/10.1039/c1cc16301a SN - 0022-4936 SN - 0009-241x SN - 1359-7345 SN - 1364-548x VL - 48 SP - 1638 EP - 1640 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-27735 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klimakow, Maria A1 - Leiterer, Jork A1 - Kneipp, Janina A1 - Rössler, E. A1 - Panne, Ulrich A1 - Rademann, K. A1 - Emmerling, Franziska T1 - Combined synchrotron XRD/Raman measurements: In situ identification of polymorphic transitions during crystallization processes JF - Langmuir N2 - A combination of two analytical methods, time-resolved X-ray diffraction (XRD) and Raman spectroscopy, is presented as a novel tool for crystallization studies. An acoustic levitator was employed as sample environment. This setup enables the acquisition of XRD and Raman data in situ simultaneously within a 20 s period and hence permits investigation of polymorphic phase transitions during the crystallization process in different solvents (methanol, ethanol, acetone, dichloromethane, acetonitrile). These real time measurements allow the determination of the phase content from the onset of the first crystalline molecular assemblies to the stable system. To evaluate the capability of this approach, the setup was applied to elucidate the crystallization process of the polymorphic compound nifedipine. The results indicate the existence of solvent-dependent transient phases during the crystallization process. The quality of the data allowed the assignment of the lattice constants of the hitherto unknown crystal structure of the β-polymorph. KW - Synchrotron radiation KW - XRD KW - Raman spectroscopy KW - Polymorphism KW - Crystallization KW - Acoustic levitation KW - Nifedipine PY - 2010 DO - https://doi.org/10.1021/la100540q SN - 0743-7463 SN - 1520-5827 VL - 26 IS - 13 SP - 11233 EP - 11237 PB - American Chemical Society CY - Washington, DC AN - OPUS4-21396 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -