TY - JOUR A1 - Dolai, Malay A1 - Saha, Urmila A1 - Goswami, Juli Nanda A1 - Bhattacharya, Biswajit A1 - Emmerling, Franziska A1 - Ifseisi, Ahmad A. A1 - Biswas, Surajit ED - Bhattacharya, Biswajit T1 - Nickel(II)-mediated in situ complex formation with unexpected ligand transformations: crystal structures, DFT calculations, and catalytic activity in CO2 fixation reactions N2 - Two transformed ligands, namely 1,3,5-triazapentadienato(imidoylamidinato) and N-(methoxy(pyrimidin-2-yl)(pyrimidine-2-carboxamido)methyl)pyrimidine-2-carboxamide, are reported here as the first products derived from 2-cyano pyridine/pyrimidine, respectively, under nickel metal mediation in the presence of hydroxylamine hydrochloride in situ. Two different nickel-coordinated complexes (1 and 2) were formed. Single crystal X-ray diffraction revealed that complex 1 is a mononuclear complex with tetra-coordinated square planar geometry, whereas complex 2 is a dinuclear complex with hexa-coordinated distorted octahedral geometry. The synthetic pathways of both transformed ligands are explained with the support of energy calculations of different states via density functional theory (DFT) calculations. The catalytic addition reactions of epoxides and carbon dioxide efficiently produce organic cyclic carbonates in the presence of complexes 1–2, attributed to the presence of Lewis acidic nickel and Lewis basic centers, such as free amine, imine, methoxy, or nitrogen in complexes 1 and 2. Under mild reaction conditions (1 atm CO2 pressure and 60 °C temperature), different types of epoxides (exocyclic, endocyclic, and aromatic epoxides) yield high levels of respective cyclic carbonates in the presence of both complexes 1–2 as catalysts, with tert-butylammonium bromide (TBAB) acting as a co-catalyst. The high turnover number (TON) and turnover frequency (TOF) of these catalytic reactions clearly indicate the efficacy of the two catalysts. KW - Catalytic activity in CO2 fixation reactions DFT calculations KW - Nickel(II)-complex KW - In situ complex formation KW - Crystal Structure PY - 2025 DO - https://doi.org/10.1039/d4nj01801j SN - 1369-9261 VL - 49 IS - 11 SP - 4451 EP - 4463 PB - Royal Society of Chemistry (RSC) AN - OPUS4-62782 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sun, Yijuan A1 - Gawlitza, Kornelia A1 - Valderrey, Virginia A1 - Bhattacharya, Biswajit A1 - Rurack, Knut T1 - Ratiometric Molecularly Imprinted Particle Probes for Reliable Fluorescence Signaling of Carboxylate-Containing Molecules N2 - In addition to sensitivity, selectivity, and portability, chemical sensing systems must generate reliable signals and offer modular configurability to address various small molecule targets, particularly in environmental applications. We present a versatile, modular strategy utilizing ratiometric molecularly imprinted particle probes based on BODIPY indicators and dyes for recognition and internal referencing. Our approach employs polystyrene core particles doped with a red fluorescent BODIPY as an internal standard, providing built-in reference for environmental influences. A molecularly imprinted polymer (MIP) recognition shell, incorporating a green-fluorescent BODIPY indicator monomer with a thiourea binding site for carboxylate containing analytes, is grafted from the core particles in the presence of the analyte as the template. The dual-fluorescent MIP probe detects fexofenadine as the model analyte with a change in green emission signal referenced against a stable red signal, achieving a detection limit of 0.13 μM and a broad dynamic range from 0.16 μM to 1.2 mM, with good discrimination against other antibiotics in acetonitrile. By selecting a versatile dye scaffold and recognition element, this approach can be extended to other carboxylate-containing analytes and/or wavelength combinations, potentially serving as a robust multiplexing platform. KW - Core-shell particles KW - Molecular imprinting KW - Pharmaceutical contaminants KW - Self-referenced measurements KW - Fluorescence PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-609385 DO - https://doi.org/10.1021/acsami.4c09990 SP - 1 EP - 13 PB - American Chemical Society (ACS) AN - OPUS4-60938 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Parthasarathy, Thiyagaraj A1 - Bhowmik, Aritra A1 - Bhattacharya, Biswajit A1 - Mishra, Manish Kumar A1 - Ghosh, Soumyajit T1 - Reversible twisting-induced crystalline–polycrystalline transformation in cyanoacrylate crystals N2 - Centimeter-long single crystals of cyanoacrylate derivatives exhibit 1D elasticity, 2D plasticity and can be manually twisted and untwisted without any visible fractures, demonstrating exceptional mechanical flexibility and structural resilience. KW - Weak intermolecular interactions KW - Crystals KW - Mechanical flexiblity KW - Micro-focus Raman spectroscopy KW - Single-crystal X-ray diffraction PY - 2025 DO - https://doi.org/10.1039/D5CC05852J SN - 1359-7345 SP - 1 EP - 4 PB - Royal Society of Chemistry (RSC) AN - OPUS4-64962 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kumari, N. A1 - Bhattacharya, Biswajit A1 - Roy, P. A1 - Michalchuk, Adam A1 - Ghosh, A. A1 - Emmerling, Franziska T1 - Enhancing the Pharmaceutical Properties of Pirfenidone by Mechanochemical Cocrystallization N2 - Pirfenidone is an important drug molecule used in the treatment of idiopathic lung fibrosis. Although approved by the USFDA in 2014, pirfenidone’s aqueous solubility is too high and must be mitigated by additives. In this work, the cocrystallization of pirfenidone is explored as an alternative approach to reducing its solubility. Herein, an anhydrous form of pirfenidone is reported, alongside its first two reported cocrystals. The new crystalline solids are thoroughly characterized by single crystal X-ray diffraction (SCXRD), powder X-ray diffraction analysis (PXRD), Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Equilibrium solubility and intrinsic dissolution rates (IDR) are studied for the cocrystals and compared to that of the parent drug. Both cocrystal forms exhibit drastically lower aqueous solubility (by up to 90%) and dissolution rates, rationalized based on both lattice energy calculations and consideration of intermolecular interactions in the solid state. Furthermore, we compare the physicochemical properties of solution-based material with that of material produced mechanochemically. Importantly, no differences are observed between the two production methods. This work demonstrates the strength of crystal Engineering strategies to beneficially modify important pharmaceutical properties and highlights the potential of mechanochemistry to facilitate this in an environmentally benign way. KW - Mechanochemistry PY - 2019 DO - https://doi.org/10.1021/acs.cgd.9b00932 VL - 19 IS - 11 SP - 6482 EP - 6492 PB - ACS Publications AN - OPUS4-49828 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bhattacharya, Biswajit A1 - Michalchuk, Adam A1 - Silbernagl, Dorothee A1 - Rautenberg, Max A1 - Schmid, Thomas A1 - Feiler, Torvid A1 - Reimann, K. A1 - Ghalgaoui, A. A1 - Sturm, Heinz A1 - Paulus, B. A1 - Emmerling, Franziska T1 - A Mechanistic Perspective on Plastically Flexible Coordination Polymers N2 - Mechanical flexibility in single crystals of covalently bound materials is a fascinating and poorly understood phenomenon. We present here the first example of a plastically flexible one-dimensional (1D) coordination polymer. The compound [Zn(m-Cl)2(3,5-dichloropyridine)2]n is flexible over two crystallographic faces. Remarkably, the single crystal remains intact when bent to 1808. A combination of microscopy, diffraction, and spectroscopic studies have been used to probe the structural response of the crystal lattice to mechanical bending. Deformation of the covalent polymer chains does not appear to be responsible for the observed macroscopic bending. Instead, our results suggest that mechanical bending occurs by displacement of the coordination polymer chains. Based on experimental and theoretical evidence, we propose a new model for mechanical flexibility in 1D coordination polymers. Moreover, our calculations propose a cause of the different mechanical properties of this compound and a structurally similar elastic material KW - Coordination polymer KW - Flexible crystals KW - Mechanical properties KW - Plastic deformation PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-504755 DO - https://doi.org/10.1002/anie.201914798 VL - 59 IS - 14 SP - 5557 EP - 5561 PB - Wiley-VCH AN - OPUS4-50475 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Feiler, Torvid A1 - Bhattacharya, Biswajit A1 - Michalchuk, Adam A1 - Schröder, V. A1 - List-Kratochvil, E. A1 - Emmerling, Franziska T1 - Mechanochemical Syntheses of Isostructural Luminescent Cocrystals of 9-Anthracenecarboxylic Acid with two Dipyridines Coformers N2 - Tuning and controlling the solid-state photophysical properties of organic luminophore are very important to develop next-generation organic luminescent materials. With the aim of discovering new functional luminescent materials, new cocrystals of 9-anthracene carboxylic acid (ACA) were prepared with two different dipyridine coformers: 1,2-bis(4-pyridyl)ethylene and 1,2-bis(4-pyridyl)ethane. The cocrystals were successfully obtained by both mechanochemical approaches and conventional solvent crystallization. The newly obtained crystalline solids were characterized thoroughly using a combination of single crystal X-ray diffraction, powder X-ray diffraction, Fourier-transform infrared spectroscopy, differential thermal analysis, and thermogravimetric analysis. Structural analysis revealed that the cocrystals are isostructural, exhibiting two-fold interpenetrated hydrogen bonded networks. While the O–H···N hydrogen bonds adopts a primary role in the stabilization of the cocrystal phases, the C–H···O hydrogen bonding interactions appear to play a significant role in guiding the three-dimensional assembly. Both π···π and C–H···π interactions assist in stabilizing the interpenetrated structure. The photoluminescence properties of both the starting materials and cocrystals were examined in their solid states. All the cocrystals display tunable photophysical properties as compared to pure ACA. Density functional theory simulations suggest that the modified optical properties result from charge transfers between the ACA and coformer molecules in each case. This study demonstrates the potential of crystal engineering to design solid-state luminescence switching materials through cocrystallization. KW - Cocrystal KW - Mechanochemical synthesis KW - Luminescence KW - X-ray diffraction KW - DFT calculation PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-518226 DO - https://doi.org/10.3390/cryst10100889 VL - 10 IS - 10 SP - 889 PB - MDPI AN - OPUS4-51822 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 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 - Liu, X. A1 - Michalchuk, Adam A1 - Bhattacharya, Biswajit A1 - Emmerling, Franziska A1 - Pulham, C. T1 - High-pressure reversibility in a plastically flexible coordination polymer crystal N2 - Single crystals which exhibit mechanical flexibility are promising materials for advanced technological applications. Before such materials can be used, a detailed understanding of the mechanisms of bending is needed. Using single crystal X-ray diffraction and microfocus Raman spectroscopy, we study in atomic detail the high-pressure response of the plastically flexible coordination polymer [Zn(μ-Cl)2(3,5-dichloropyridine)2]n (1). Contradictory to three-point bending, quasi-hydrostatic compression of (1) is completely reversible, even following compression to over 9 GPa. A structural phase transition is observed at ca. 5 GPa. DFT calculations show this transition to result from the pressure-induced softening of low-frequency vibrations. This phase transition is not observed during three-point-bending. Microfocus synchrotron X-ray diffraction revealed that bending yields significant mosaicity, as opposed to compression. Hence, our studies indicate of overall disparate mechanical responses of bulk flexibility and quasi-hydrostatic compression within the same crystal lattice. We suspect this to be a general feature of plastically bendable materials. KW - High pressure KW - Density functional theory KW - Mechanically flexible crystals PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-530360 DO - https://doi.org/10.1038/s41467-021-24165-x VL - 12 IS - 1 SP - 3871 AN - OPUS4-53036 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Karafiludis, Stephanos A1 - Bhattacharya, Biswajit A1 - de Oliveira Guilherme Buzanich, Ana A1 - Fink, Friedrich A1 - Feldmann, Ines A1 - ten Elshof, J. E. A1 - Emmerling, Franziska A1 - Stawski, Tomasz T1 - Thermally processed Ni-and Co-struvites as functional materials for proton conductivity N2 - We present how mesoporosity can be engineered in transition metal phosphate (TMPs) materials in a template-free manner. The method involves the transformation of a precursor metal phosphate phase, called M-struvite (NH4MPO4·6H2O, M = Mg2+, Ni2+, Co2+, NixCo1−x2+). It relies on the thermal decomposition of crystalline M-struvite precursors to an amorphous and simultaneously mesoporous phase, which forms during degassing of NH3 and H2O. The temporal evolution of mesoporous frameworks and the response of the metal coordination environment were followed by in situ and ex situ scattering and diffraction, as well as X-ray spectroscopy. Despite sharing the same precursor struvite structure, different amorphous and mesoporous structures were obtained depending on the involved transition metal. We highlight the systematic differences in absolute surface area, pore shape, pore size, and phase transitions depending on the metal cation present in the analogous M-struvites. The amorphous structures of thermally decomposed Mg-, Ni- and NixCo1−x-struvites exhibit high surface areas and pore volumes (240 m2 g−1 and 0.32 cm−3 g−1 for Mg and 90 m2 g−1 and 0.13 cm−3 g−1 for Ni). We propose that the low-cost, environmentally friendly M-struvites could be obtained as recycling products from industrial and agricultural wastewaters. These waste products could be then upcycled into mesoporous TMPs through a simple thermal treatment for further application, for instance in (electro)catalysis. KW - Struvite KW - Phosphates KW - Transition metals KW - Proton conductivity PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-575862 DO - https://doi.org/10.1039/D3DT00839H SN - 1477-9226 SP - 1 EP - 13 PB - Royal Society of Chemisty (RSC) CY - London/Cambridge AN - OPUS4-57586 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rautenberg, Max A1 - Akhmetova, Irina A1 - Das, Chayanika A1 - Bhattacharya, Biswajit A1 - Emmerling, Franziska T1 - Synthesis and In Situ Monitoring of Mechanochemical Preparation of Highly Proton Conductive Hydrogen-Bonded Metal Phosphonates N2 - Crystalline porous materials are recognized as promising proton conductors for the proton exchange membrane (PEM) in fuel cell technology owing to their tunable framework structure. However, it is still a challenging bulk synthesis for real-world applications of these materials. Herein, we report the mechanochemical gram-scale synthesis of two isostructural metal hydrogen-bonded organic frameworks (MHOFs) of Co(II) and Ni(II) based on 1-hydroxyethylidenediphosphonic acid (HEDPH4) with 2,2′-bipyridine (2,2′-bipy): Co(HEDPH3)2(2,2′-bipy)·H2O (1) and Ni(HEDPH3)2(2,2′-bipy)·H2O (2). In situ monitoring of the mechanochemical synthesis using different synchrotron-based techniques revealed a one-step mechanism – the starting materials are directly converted to the product. With the existence of extensive hydrogen bonds with amphiprotic uncoordinated phosphonate hydroxyl and oxygen atoms, both frameworks exhibited proton conduction in the range of 10–4 S cm–1 at room temperature under humid conditions. This study demonstrates the potential of green mechanosynthesis for bulk material preparation of framework-based solid-state proton conductors. KW - Mechanochemistry KW - Proton conductivity KW - Metal Organic Frameworks PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-577777 DO - https://doi.org/10.1021/acssuschemeng.2c07509 VL - 8 IS - 19 SP - 16687 EP - 16693 PB - ACS Publications AN - OPUS4-57777 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska A1 - Michalchuk, Adam A1 - Bhattacharya, Biswajit A1 - Rodríguez Sánchez, Noelia A1 - Gugin, Nikita T1 - Advancing sustainable synthesis through in situ monitoring and industrial scale-up of mechanochemical processes N2 - Mechanochemistry has emerged as a powerful approach for sustainable materials synthesis and processing, with significant potential to meet the UN Sustainable Development Goals. This presentation will highlight our recent advancements in understanding, monitoring, and scaling-up mechanochemical transformations, focusing on the balance between fundamental understanding of reaction mechanisms and its practical applications in energy storage and energy transfer materials. Our research has made significant strides in elucidating the fundamental mechanisms of mechanochemical reactions. We have investigated delayed polymorphism under mechanochemical conditions, revealing new insights into the interplay between mechanical impact, thermal effects, and structural transformations in molecular crystals. By employing variable temperature ball milling, we have demonstrated unprecedented control over polymorphic forms in organic cocrystals, opening new avenues for tailoring material properties. A central focus of our work has been the development and application of time-resolved in situ monitoring techniques for mechanochemical processes. Our research on real-time synchrotron X-ray diffraction has enabled unprecedented insights into reaction pathways and kinetics. Recently, we have successfully applied energy-dispersive X-ray diffraction for time-resolved in situ monitoring of reactive extrusion, marking a significant step towards ‘lighting up’ industrial-scale mechanochemistry. Bridging fundamental understanding with practical applications, we have explored the mechanochemical synthesis of functional materials for energy storage and transfer, making process in the mechanochemical synthesis of highly proton-conductive metal phosphonates, demonstrating the potential of mechanochemistry to manufacture advanced materials for energy applications. Addressing the challenges of industrial scale-up, we have investigated the role of solvent polarity in mechanochemical reactions, providing valuable guidance for optimizing organic syntheses such as the Knoevenagel condensation. This work contributes to our broader efforts to develop more efficient and sustainable chemical manufacturing processes. Looking to the future, we will discuss emerging directions in mechanochemistry, including the development of continuous flow processes and the integration of machine learning approaches for reaction prediction and optimization. As we anticipate the next decade of research, we envision mechanochemistry playing an increasingly crucial role in sustainable chemical manufacturing and materials processing, with far-reaching implications for addressing global energy and environmental challenges. T2 - Mech’cheM 2025: New forces in Mechanochemistry Conference CY - Montpellier, France DA - 04.06.2025 KW - Phosphonates KW - Biocomposites PY - 2025 AN - OPUS4-64845 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska A1 - Michalchuk, Adam A1 - Bhattacharya, Biswajit A1 - Rodríguez Sánchez, Noelia A1 - Gugin, Nikita T1 - Mechanochemical innovations for sustainable synthesis of framework materials and industrial scaleup N2 - Mechanochemistry has emerged as a powerful approach for sustainable materials synthesis and processing, with significant potential to meet the UN Sustainable Development Goals. This presentation will highlight our recent advancements in understanding, monitoring, and scaling-up mechanochemical synthesis of framework materials, focusing on the balance between fundamental understanding of reaction mechanisms and its practical applications in energy storage and energy transfer materials. A central focus of our work has been the development and application of time-resolved in situ monitoring techniques for mechanochemical processes. Our research on real-time synchrotron X-ray diffraction has enabled unprecedented insights into reaction pathways and kinetics. Recently, we have successfully applied energy-dispersive X-ray diffraction for time-resolved in situ monitoring of reactive extrusion, marking a significant step towards ‘lighting up’ industrial-scale mechanochemistry. Bridging fundamental understanding with practical applications, we have explored the mechanochemical synthesis of functional materials for energy storage and transfer, making process in the mechanochemical synthesis of highly proton-conductive metal phosphonates, demonstrating the potential of mechanochemistry to manufacture advanced materials for energy applications. T2 - 17. international-conference für Materialchemie CY - Edinburgh, United Kingdom DA - 07.07.2025 KW - MOF KW - Synchrotron KW - ZIF PY - 2025 AN - OPUS4-64841 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ravi, J. A1 - Feiler, Torvid A1 - Mondal, A. A1 - Michalchuk, Adam A1 - Reddy, C. M. A1 - Bhattacharya, Biswajit A1 - Emmerling, Franziska A1 - Chandrasekar, R. T1 - Plastically bendable organic crystals for monolithic and hybrid micro-optical circuits N2 - Fluorescent plastically bendable crystals are a promising alternative to silicon-based materials for fabricating photonic integrated circuits, owing to their optical attributes and mechanical compliance. Mechanically bendable plastic organic crystals are rare. Their formation requires anisotropic intermolecular interactions and slip planes in the crystal lattice. This work presents three fluorescent plastically bendable crystalline materials namely, 2-((E)-(6-methylpyridin-2-ylimino)methyl)-4-chlorophenol (SB1), 2-((E)-(6-methylpyridin-2-ylimino)methyl)-4-bromophenol (SB2), and 2-((E)-(6-Bromopyridin-2-ylimino)methyl)-4-bromophenol (SB3) molecules. The crystal plasticity in response to mechanical stress facilitates the fabrication of various monolithic and hybrid (with a tip-to-tip coupling) photonic circuits using mechanical micromanipulation with an atomic force microscope cantilever tip. These plastically bendable crystals act as active (self-guiding of fluorescence) and passive waveguides both in straight and extremely bent (U-, J-, and O-shaped) geometries. These microcircuits use active and passive waveguiding principles and reabsorbance and energy-transfer mechanisms for their operation, allowing input-selective and direction-specific signal transduction. KW - Flexible crystals KW - Flexible waveguide PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-565302 DO - https://doi.org/10.1002/adom.202201518 SN - 2195-1071 SP - 1 EP - 10 PB - Wiley-VCH CY - Weinheim AN - OPUS4-56530 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bhattacharya, Biswajit A1 - Michalchuk, Adam A1 - Silbernagl, Dorothee A1 - Yasuda, N. A1 - Feiler, Torvid A1 - Sturm, Heinz A1 - Emmerling, Franziska T1 - An atomistic mechanism for elasto-plastic bending in molecular crystals N2 - Mechanically flexible single crystals of molecular materials offer potential for a multitude of new directions in advanced materials design. Before the full potential of such materials can be exploited, insight into their mechanisms of action must be better understood. Such insight can be only obtained through synergistic use of advanced experimentation and simulation. We herein report the first detailed mechanistic study of elasto-plastic flexibility in a molecular solid. An atomistic origin for this mechanical behaviour is proposed through a combination of atomic force microscopy, μ-focus synchrotron X-ray diffraction, Raman spectroscopy, ab initio simulation, and computed elastic tensors. Our findings suggest that elastic and plastic bending are intimately linked and result from extensions of the same molecular deformations. The proposed mechanism bridges the gap between contested mechanisms, suggesting its applicability as a general mechanism for elastic and plastic bending in organic molecular crystals. KW - Mechanical property KW - Mechanical flexibility KW - Organic crystal PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-577722 DO - https://doi.org/10.1039/D2SC06470G SN - 2041-6520 VL - 14 IS - 13 SP - 3441 EP - 3450 PB - Royal Society of Chemisty (RSC) CY - London/Cambridge AN - OPUS4-57772 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lakshmipathi, M. A1 - Dey, S. A1 - Emmerling, Franziska A1 - Bhattacharya, Biswajit A1 - Michalchuk, Adam T1 - Designing Dual Mechanical Response in Molecular Crystals through Cocrystallization N2 - Two isomorphous crystals are reported based on a naphthylvinylpyridine coformer. The crystals are mechanically flexible and exhibit photosalient response to UV irradiation. We therefore show how multiple mechanical phenomena can be simultaneously designed into a single material by cocrystallization. KW - Cocrystal KW - Mechanical response PY - 2022 DO - https://doi.org/10.1021/acs.cgd.2c00913 SN - 1528-7483 VL - 22 SP - 6838 EP - 6843 PB - ACS Publ. CY - Washington, DC AN - OPUS4-56561 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Feiler, Torvid A1 - Yasuda, N. A1 - Michalchuk, Adam A1 - Emmerling, Franziska A1 - Bhattacharya, Biswajit T1 - Mechanistic Investigation of an Elastically Flexible Organic Crystal N2 - Mechanical flexibility in molecular crystals is a fascinating behavior with potential for developing advanced technologies. However, the phenomenon of mechanical bending is poorly understood. We explore for the first time the atomistic origin of elastic bending in a single component organic crystal using a combination of μ-focus synchrotron X-ray diffraction and ab initio simulation. KW - Flexible crystals KW - DFT calculation KW - Bending mechanism PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-581949 DO - https://doi.org/10.1021/acs.cgd.3c00473 SN - 1528-7483 VL - 23 IS - 9 SP - 6244 EP - 6249 PB - ACS Publications AN - OPUS4-58194 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rodríguez-Sánchez, Noelia A1 - Bhattacharya, Biswajit A1 - Emmerling, Franziska A1 - Prinz, Carsten A1 - Prieto-Laria, P. A1 - Ruiz-Salvador, A.R. A1 - Ballesteros, M. T1 - Engineering a multivariate cobalt metal–organic framework for high photocatalytic activity: the impact of mixed ligands and metal incorporation in a visible light-driven heterogeneous photo-Fenton reaction for water treatment N2 - Metal–organic frameworks (MOFs) have attracted increasing attention for the removal of organic pollutants in wastewater via photocatalysis. Here, we design a multivariate modification of ZIF-9 to tune its electronic properties for use in visible light photocatalysis. A controllable synthesis of ZIF-9 and its multivariate forms with the incorporation of copper and the 2-imidazolecarboxaldehyde (ica) ligand was carried out. The materials are tested for the removal of the model dye methylene blue (MB) by a heterogeneous photo-Fenton-like reaction at neutral pH and room temperature. Cu-ZIF-9-ica (UPO-3) shows high photocatalytic activity under both visible and ultraviolet A (UVA) light, achieving 94% MB degradation in 45 min, compared to 65% MB degradation in 120 min using bare ZIF-9. The study revealed a first-order rate constant of 0.0475 min−1 for Cu-ZIF-9-ica compared to 0.0088 min−1 for ZIF-9 under visible light. The improvement of the catalyst was clearly attributed to the co-incorporation of Cu and the ica ligand in the MOF, which reduces the band gap, in agreement with DFT calculations. Reproducibility and recyclability tests proved that Cu-ZIF-9-ica can be used for at least 3 cycles without a significant loss of efficiency, making it a promising material for the study and application of wastewater treatment. KW - Metal-Organic Framework (MOF) KW - Heterogeneous photo-Fenton KW - ZIF-9 KW - Methylene Blue PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630797 DO - https://doi.org/10.1039/d4na00954a SN - 2516-0230 VL - 7 IS - 8 SP - 2255 EP - 2265 PB - Royal Society of Chemistry AN - OPUS4-63079 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rodríguez-Sánchez, Noelia A1 - Domínguez-Santos, J. Enrique A1 - Bhattacharya, Biswajit A1 - Prinz, Carsten A1 - Canosa, Inés A1 - Flores, Amando A1 - Jiménez-Rodríguez, Antonia A1 - Ruiz-Salvador, A. Rabdel A1 - Emmerling, Franziska A1 - Ballesteros, Menta T1 - Mechanochemical synthesis of multivariate UPO-3 (Cu-ZIF-9-ica) MOF for inactivation of antibiotic-resistant bacteria and irrigation-quality water production via heterogeneous photo-Fenton catalysis N2 - Water scarcity and pollution are critical global challenges, particularly in agriculture, the largest consumer of water. The development of sustainable, effective, and environmentally friendly disinfection methods is essential to address the risks posed by antibiotic-resistant bacteria and to ensure safe reuse of water for irrigation. In this study, we report the synthesis of the metal-organic framework (MOF) Universidad Pablo de Olavide-3 (UPO-3) via a mechanochemical approach, a scalable and sustainable method compared to traditional solvothermal synthesis. The resulting UPO-3/H2O2 system exhibits robust photocatalytic properties under visible light, achieving effective and broad-spectrum antibacterial activity. The disinfection efficiency of the catalyst was evaluated against Escherichia coli as a model of microbial pathogen in two saline matrices, considering the key parameters of the heterogeneous photo-Fenton process, including catalyst dosage, initial H2O2 concentration, and light irradiation. Notably, it inactivated two important virulent and antibiotic-resistant bacterial pathogens (Staphylococcus aureus and Pseudomonas aeruginosa). Furthermore, UPO-3 shows exceptional performance under real-world conditions, such as river water disinfection, achieving >5-log reduction of E. coli, fulfilling a critical criterion for Class A water reuse under Regulation (EU) 2020/741. These results highlight UPO-3 as a versatile and sustainable solution for water reuse, addressing water scarcity and advancing efforts to achieve United Nations Sustainable Development Goal 6. KW - Water reuse KW - Antibiotic-resistant bacteria KW - Water disinfection KW - Mechanochemical synthesis KW - Metal organic framework PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-639766 DO - https://doi.org/10.1016/j.chemosphere.2025.144610 SN - 0045-6535 VL - 386 SP - 1 EP - 11 PB - Elsevier Ltd. AN - OPUS4-63976 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Feiler, Torvid A1 - Emmerling, Franziska A1 - Bhattacharya, Biswajit T1 - Sustainable mechanochemical approach for the selective synthesis of multicomponent organic solids: real-time in situ insights N2 - Crystalline multicomponent organic solids (MOSs) such as cocrystals and ionic cocrystals hold immense potential in diverse functional applications, ranging from pharmaceuticals to optoelectronics. However, conventional solution-based crystallization methods often result in polymorphic mixtures and lack precise control over product composition. Herein, we report a comparative investigation of solution crystallization versus mechanochemical synthesis for constructing MOSs from 9-anthracenecarboxylic acid (ACA) and 4,4 '-bipyridine (BPY). Solution-based approaches consistently yielded concomitant formation of neutral cocrystal (CC) and ionic cocrystal (ICC) forms, regardless of the solvent used. The resulting multicomponent solids were comprehensively characterized using a combination of single crystal X-ray diffraction, powder X-ray diffraction, Fourier-transform infrared spectroscopy, differential thermal analysis, and thermogravimetric analysis. In contrast, mechanochemical methods, including neat grinding (without solvent) and liquid-assisted grinding (with minimum solvent), enabled selective formation of either a phase pure CC or ICC form. Less polar and nonpolar organic solvents favor the kinetic CC, while polar water promotes formation of the thermodynamically stable ICC. Time-resolved in situ powder X-ray diffraction (TRIS-PXRD) captures the dynamic evolution of solid-state phases and reveals the complete transformation of the CC into ICC under neat grinding or water-assisted conditions. This study highlights the powerful role of mechanochemistry and in situ monitoring in steering solid-state reactivity and offers a sustainable pathway for the targeted and scalable synthesis of pure multicomponent organic materials. KW - Cocrystal KW - Synchrotron X-ray powder diffraction KW - Time-resolved in situ investigation PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-641409 DO - https://doi.org/10.1039/D5CE00663E SN - 1466-8033 SP - 1 EP - 9 PB - Royal Society of Chemistry (RSC) CY - Cambridge AN - OPUS4-64140 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Paul, Sagar A1 - Dolai, Malay A1 - Nanda Goswami, Juli A1 - Bhattacharya, Biswajit A1 - Emmerling, Franziska A1 - Drew, Michael G. B. A1 - Chattopadhyay, Shouvik A1 - Sarkar, Rabi Sankar A1 - Sunil, Appu A1 - Novitchi, Ghenadie A1 - Moreno-Pineda, Eufemio A1 - Wernsdorfer, Wolfgang T1 - From strong to weak interaction: Reconciling SQUID and μSQUID-EPR data in anomalous Co(ii) dimers N2 - Magnetic molecules have been proposed as scaffolds for novel quantum technologies, ranging from quantum sensing and quantum memory to multilevel quantum bits (qudits) and fault-tolerant quantum computation. Integration of magnetic molecules into cutting-edge applications hinges on a deep understanding and tunability of their spin states. To date, the strategic manipulation of the local environment of the ion and careful selection of the magnetic core have enabled the desired tunability and scalability of the spin states. For such goals, however, extracting the anisotropic parameters that dictate the characteristics of the Spin Hamiltonian is challenging, especially for molecules consisting of multiple magnetic cores. We address these challenges by studying two cobalt(II) dinuclear systems, complicated by inherent spin–orbit coupling. We explore the magnetic properties of these systems in two temperature regimes: (i) at sub-Kelvin temperatures employing single crystals at 30 mK using a unique μSQUID-EPR technique that examines the microwave absorption peaks in the magnetisation data and their variation with field angle and frequency; and (ii) in bulk employing convectional SQUID magnetometry above 2 K i.e., χMT(T) and M(H). Unexpectedly, sub-Kelvin temperature investigations reveal a negligible interaction, whereas the SQUID data reveal a much stronger interaction between the Co(II) ions. An understanding of these data is developed based on a strong coupling model and the coupling of two moieties with a spin-effective ground state. KW - cOBALT(II)-complex KW - In situ complex formation KW - Magnetic property KW - Crystal structure PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-641421 DO - https://doi.org/10.1039/D5QI01387A SN - 2052-1553 SP - 1 EP - 13 PB - Royal Society of Chemistry (RSC) CY - Cambridge AN - OPUS4-64142 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -