TY - JOUR
AB - The multicomponent approach allows to incorporate several functionalities into a single covalent organic framework (COF) and consequently allows the construction of bifunctional materials for cooperative catalysis. The well-defined structure of such multicomponent COFs is furthermore ideally suited for structure-activity relationship studies. We report a series of multicomponent COFs that contain acridine- and 2,2’-bipyridine linkers connected through 1,3,5-benzenetrialdehyde derivatives. The acridine motif is responsible for broad light absorption, while the bipyridine unit enables complexation of nickel catalysts. These features enable the usage of the framework materials as catalysts for light-mediated carbon−heteroatom cross-couplings. Variation of the node units shows that the catalytic activity correlates to the keto-enamine tautomer isomerism. This allows switching between high charge-carrier mobility and persistent, localized charge-separated species depending on the nodes, a tool to tailor the materials for specific reactions. Moreover, nickel-loaded COFs are recyclable and catalyze cross-couplings even using red light irradiation.
AU - Traxler, Michael
AU - Reischauer, Susanne
AU - Vogl, Sarah
AU - Roeser, Jérôme
AU - Rabeah, Jabor
AU - Penschke, Christopher
AU - Saalfrank, Peter
AU - Pieber, Bartholomäus
AU - Thomas, Arne
ID - 12920
IS - 4
JF - Chemistry – A European Journal
KW - General Chemistry
KW - Catalysis
KW - Organic Chemistry
SN - 0947-6539
TI - Programmable photocatalytic activity of multicomponent covalent organic frameworks used as metallaphotocatalysts
VL - 29
ER -
TY - JOUR
AB - Integrating light-sensitive molecules within nanoparticle (NP) assemblies is an attractive approach to fabricate new photoresponsive nanomaterials. Here, we describe the concept of photocleavable anionic glue (PAG): small trianions capable of mediating interactions between (and inducing the aggregation of) cationic NPs by means of electrostatic interactions. Exposure to light converts PAGs into dianionic products incapable of maintaining the NPs in an assembled state, resulting in light-triggered disassembly of NP aggregates. To demonstrate the proof-of-concept, we work with an organic PAG incorporating the UV-cleavable o-nitrobenzyl moiety and an inorganic PAG, the photosensitive trioxalatocobaltate(III) complex, which absorbs light across the entire visible spectrum. Both PAGs were used to prepare either amorphous NP assemblies or regular superlattices with a long-range NP order. These NP aggregates disassembled rapidly upon light exposure for a specific time, which could be tuned by the incident light wavelength or the amount of PAG used. Selective excitation of the inorganic PAG in a system combining the two PAGs results in a photodecomposition product that deactivates the organic PAG, enabling nontrivial disassembly profiles under a single type of external stimulus.
AU - Wang, Jinhua
AU - Peled, Tzuf Shay
AU - Klajn, Rafal
ID - 13354
IS - 7
JF - Journal of the American Chemical Society
KW - Colloid and Surface Chemistry
KW - Biochemistry
KW - General Chemistry
KW - Catalysis
SN - 0002-7863
TI - Photocleavable anionic glues for light-responsive nanoparticle aggregates
VL - 145
ER -
TY - JOUR
AB - The power factor of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) film can be significantly improved by optimizing the oxidation level of the film in oxidation and reduction processes. However, precise control over the oxidation and reduction effects in PEDOT:PSS remains a challenge, which greatly sacrifices both S and σ. Here, we propose a two-step post-treatment using a mixture of ethylene glycol (EG) and Arginine (Arg) and sulfuric acid (H2SO4) in sequence to engineer high-performance PEDOT:PSS thermoelectric films. The high-polarity EG dopant removes the excess non-ionized PSS and induces benzenoid-to-quinoid conformational change in the PEDOT:PSS films. In particular, basic amino acid Arg tunes the oxidation level of PEDOT:PSS and prevents the films from over-oxidation during H2SO4 post-treatment, leading to increased S. The following H2SO4 post-treatment further induces highly orientated lamellar stacking microstructures to increase σ, yielding a maximum power factor of 170.6 μW m−1 K−2 at 460 K. Moreover, a novel trigonal-shape thermoelectric device is designed and assembled by the as-prepared PEDOT:PSS films in order to harvest heat via a vertical temperature gradient. An output power density of 33 μW cm−2 is generated at a temperature difference of 40 K, showing the potential application for low-grade wearable electronic devices.
AU - Zhang, Li
AU - Liu, Xingyu
AU - Wu, Ting
AU - Xu, Shengduo
AU - Suo, Guoquan
AU - Ye, Xiaohui
AU - Hou, Xiaojiang
AU - Yang, Yanling
AU - Liu, Qingfeng
AU - Wang, Hongqiang
ID - 12113
JF - Applied Surface Science
KW - Surfaces
KW - Coatings and Films
KW - Condensed Matter Physics
KW - Surfaces and Interfaces
KW - General Physics and Astronomy
KW - General Chemistry
SN - 0169-4332
TI - Two-step post-treatment to deliver high performance thermoelectric device with vertical temperature gradient
VL - 613
ER -
TY - JOUR
AB - The influence of structural modifications on the catalytic activity of carbon materials is poorly understood. A collection of carbonaceous materials with different pore networks and high nitrogen content was characterized and used to catalyze four reactions to deduce structure–activity relationships. The CO2 cycloaddition and Knoevenagel reaction depend on Lewis basic sites (electron-rich nitrogen species). The absence of large conjugated carbon domains resulting from the introduction of large amounts of nitrogen in the carbon network is responsible for poor redox activity, as observed through the catalytic reduction of nitrobenzene with hydrazine and the catalytic oxidation of 3,3′,5,5′-tetramethylbenzidine using hydroperoxide. The material with the highest activity towards Lewis acid catalysis (in the hydrolysis of (dimethoxymethyl)benzene to benzaldehyde) is the most effective for small molecule activation and presents the highest concentration of electron-poor nitrogen species.
AU - Lepre, Enrico
AU - Rat, Sylvain
AU - Cavedon, Cristian
AU - Seeberger, Peter H.
AU - Pieber, Bartholomäus
AU - Antonietti, Markus
AU - López‐Salas, Nieves
ID - 12922
IS - 2
JF - Angewandte Chemie International Edition
KW - General Chemistry
KW - Catalysis
SN - 1433-7851
TI - Catalytic properties of high nitrogen content carbonaceous materials
VL - 62
ER -
TY - JOUR
AB - Characterizing and controlling entanglement in quantum materials is crucial for the development of next-generation quantum technologies. However, defining a quantifiable figure of merit for entanglement in macroscopic solids is theoretically and experimentally challenging. At equilibrium the presence of entanglement can be diagnosed by extracting entanglement witnesses from spectroscopic observables and a nonequilibrium extension of this method could lead to the discovery of novel dynamical phenomena. Here, we propose a systematic approach to quantify the time-dependent quantum Fisher information and entanglement depth of transient states of quantum materials with time-resolved resonant inelastic x-ray scattering. Using a quarter-filled extended Hubbard model as an example, we benchmark the efficiency of this approach and predict a light-enhanced many-body entanglement due to the proximity to a phase boundary. Our work sets the stage for experimentally witnessing and controlling entanglement in light-driven quantum materials via ultrafast spectroscopic measurements.
AU - Hales, Jordyn
AU - Bajpai, Utkarsh
AU - Liu, Tongtong
AU - Baykusheva, Denitsa Rangelova
AU - Li, Mingda
AU - Mitrano, Matteo
AU - Wang, Yao
ID - 13989
JF - Nature Communications
KW - General Physics and Astronomy
KW - General Biochemistry
KW - Genetics and Molecular Biology
KW - General Chemistry
KW - Multidisciplinary
TI - Witnessing light-driven entanglement using time-resolved resonant inelastic X-ray scattering
VL - 14
ER -
TY - JOUR
AB - Physical catalysts often have multiple sites where reactions can take place. One prominent example is single-atom alloys, where the reactive dopant atoms can preferentially locate in the bulk or at different sites on the surface of the nanoparticle. However, ab initio modeling of catalysts usually only considers one site of the catalyst, neglecting the effects of multiple sites. Here, nanoparticles of copper doped with single-atom rhodium or palladium are modeled for the dehydrogenation of propane. Single-atom alloy nanoparticles are simulated at 400–600 K, using machine learning potentials trained on density functional theory calculations, and then the occupation of different single-atom active sites is identified using a similarity kernel. Further, the turnover frequency for all possible sites is calculated for propane dehydrogenation to propene through microkinetic modeling using density functional theory calculations. The total turnover frequencies of the whole nanoparticle are then described from both the population and the individual turnover frequency of each site. Under operating conditions, rhodium as a dopant is found to almost exclusively occupy (111) surface sites while palladium as a dopant occupies a greater variety of facets. Undercoordinated dopant surface sites are found to tend to be more reactive for propane dehydrogenation compared to the (111) surface. It is found that considering the dynamics of the single-atom alloy nanoparticle has a profound effect on the calculated catalytic activity of single-atom alloys by several orders of magnitude.
AU - Bunting, Rhys
AU - Wodaczek, Felix
AU - Torabi, Tina
AU - Cheng, Bingqing
ID - 13216
IS - 27
JF - Journal of the American Chemical Society
KW - Colloid and Surface Chemistry
KW - Biochemistry
KW - General Chemistry
KW - Catalysis
SN - 0002-7863
TI - Reactivity of single-atom alloy nanoparticles: Modeling the dehydrogenation of propane
VL - 145
ER -
TY - GEN
AB - Cover Page
AU - Becker, Lea Marie
AU - Berbon, Mélanie
AU - Vallet, Alicia
AU - Grelard, Axelle
AU - Morvan, Estelle
AU - Bardiaux, Benjamin
AU - Lichtenecker, Roman
AU - Ernst, Matthias
AU - Loquet, Antoine
AU - Schanda, Paul
ID - 14861
IS - 19
KW - General Chemistry
KW - Catalysis
SN - 1433-7851
T2 - Angewandte Chemie International Edition
TI - Cover Picture: The rigid core and flexible surface of amyloid fibrils probed by Magic‐Angle‐Spinning NMR spectroscopy of aromatic residues
VL - 62
ER -
TY - JOUR
AB - The short history of research on Li-O2 batteries has seen a remarkable number of mechanistic U-turns over the years. From the initial use of carbonate electrolytes, that were then found to be entirely unsuitable, to the belief that (su)peroxide was solely responsible for degradation, before the more reactive singlet oxygen was found to form, to the hypothesis that capacity depends on a competing surface/solution mechanism before a practically exclusive solution mechanism was identified. Herein, we argue for an ever-fresh look at the reported data without bias towards supposedly established explanations. We explain how the latest findings on rate and capacity limits, as well as the origin of side reactions, are connected via the disproportionation (DISP) step in the (dis)charge mechanism. Therefrom, directions emerge for the design of electrolytes and mediators on how to suppress side reactions and to enable high rate and high reversible capacity.
AU - Jethwa, Rajesh B
AU - Mondal, Soumyadip
AU - Pant, Bhargavi
AU - Freunberger, Stefan Alexander
ID - 14687
JF - Angewandte Chemie International Edition
KW - General Chemistry
KW - Catalysis
SN - 1433-7851
TI - To DISP or not? The far‐reaching reaction mechanisms underpinning Lithium‐air batteries
ER -
TY - JOUR
AB - Aromatic side chains are important reporters of the plasticity of proteins, and often form important contacts in protein--protein interactions. By studying a pair of structurally homologous cross-β amyloid fibrils, HET-s and HELLF, with a specific isotope-labeling approach and magic-angle-spinning (MAS) NMR, we have characterized the dynamic behavior of Phe and Tyr aromatic rings to show that the hydrophobic amyloid core is rigid, without any sign of "breathing motions" over hundreds of milliseconds at least. Aromatic residues exposed at the fibril surface have a rigid ring axis but undergo ring flips, on a variety of time scales from ns to µs. Our approach provides direct insight into hydrophobic-core motions, enabling a better evaluation of the conformational heterogeneity generated from a NMR structural ensemble of such amyloid cross-β architecture.
AU - Becker, Lea Marie
AU - Berbon, Mélanie
AU - Vallet, Alicia
AU - Grelard, Axelle
AU - Morvan, Estelle
AU - Bardiaux, Benjamin
AU - Lichtenecker, Roman
AU - Ernst, Matthias
AU - Loquet, Antoine
AU - Schanda, Paul
ID - 12675
IS - 19
JF - Angewandte Chemie International Edition
KW - General Chemistry
KW - Catalysis
SN - 1433-7851
TI - The rigid core and flexible surface of amyloid fibrils probed by Magic‐Angle Spinning NMR of aromatic residues
VL - 62
ER -
TY - JOUR
AB - We demonstrate that several visible-light-mediated carbon−heteroatom cross-coupling reactions can be carried out using a photoactive NiII precatalyst that forms in situ from a nickel salt and a bipyridine ligand decorated with two carbazole groups (Ni(Czbpy)Cl2). The activation of this precatalyst towards cross-coupling reactions follows a hitherto undisclosed mechanism that is different from previously reported light-responsive nickel complexes that undergo metal-to-ligand charge transfer. Theoretical and spectroscopic investigations revealed that irradiation of Ni(Czbpy)Cl2 with visible light causes an initial intraligand charge transfer event that triggers productive catalysis. Ligand polymerization affords a porous, recyclable organic polymer for heterogeneous nickel catalysis of cross-coupling reactions. The heterogeneous catalyst shows stable performance in a packed-bed flow reactor during a week of continuous operation.
AU - Cavedon, Cristian
AU - Gisbertz, Sebastian
AU - Reischauer, Susanne
AU - Vogl, Sarah
AU - Sperlich, Eric
AU - Burke, John H.
AU - Wallick, Rachel F.
AU - Schrottke, Stefanie
AU - Hsu, Wei‐Hsin
AU - Anghileri, Lucia
AU - Pfeifer, Yannik
AU - Richter, Noah
AU - Teutloff, Christian
AU - Müller‐Werkmeister, Henrike
AU - Cambié, Dario
AU - Seeberger, Peter H.
AU - Vura‐Weis, Josh
AU - van der Veen, Renske M.
AU - Thomas, Arne
AU - Pieber, Bartholomäus
ID - 12924
IS - 46
JF - Angewandte Chemie International Edition
KW - General Chemistry
KW - Catalysis
SN - 1433-7851
TI - Intraligand charge transfer enables visible‐light‐mediated Nickel‐catalyzed cross-coupling reactions
VL - 61
ER -
TY - JOUR
AB - Photoredox-mediated Ni-catalyzed cross-couplings are powerful transformations to form carbon–heteroatom bonds and are generally photocatalyzed by noble metal complexes. Low-cost and easy-to-prepare carbon dots (CDs) are attractive quasi-homogeneous photocatalyst alternatives, but their applicability is limited by their short photoluminescence (PL) lifetimes. By tuning the surface and PL properties of CDs, we designed colloidal CD nano-photocatalysts for a broad range of Ni-mediated cross-couplings between aryl halides and nucleophiles. In particular, a CD decorated with amino groups permitted coupling to a wide range of aryl halides and thiols under mild, base-free conditions. Mechanistic studies suggested dynamic quenching of the CD excited state by the Ni co-catalyst and identified that pyridinium iodide (pyHI), a previously used additive in metallaphotocatalyzed cross-couplings, can also act as a photocatalyst in such transformations.
AU - Zhao, Zhouxiang
AU - Pieber, Bartholomäus
AU - Delbianco, Martina
ID - 12923
IS - 22
JF - ACS Catalysis
KW - Catalysis
KW - General Chemistry
TI - Modulating the surface and photophysical properties of carbon dots to access colloidal photocatalysts for cross-couplings
VL - 12
ER -
TY - JOUR
AB - Molecular confinement effects can profoundly alter the physicochemical properties of the confined species. A plethora of organic molecules were encapsulated within the cavities of supramolecular hosts, and the impact of the cavity size and polarity was widely investigated. However, the extent to which the properties of the confined guests can be affected by the symmetry of the cage─which dictates the shape of the cavity─remains to be understood. Here we show that cage symmetry has a dramatic effect on the equilibrium between two isomers of the encapsulated spiropyran guests. Working with two Pd-based coordination cages featuring similarly sized but differently shaped hydrophobic cavities, we found a highly selective stabilization of the isomer whose shape matches that of the cavity of the cage. A Td-symmetric cage stabilized the spiropyrans’ colorless form and rendered them photochemically inert. In contrast, a D2h-symmetric cage favored the colored isomer, while maintaining reversible photoswitching between the two states of the encapsulated spiropyrans. We also show that the switching kinetics strongly depend on the substitution pattern on the spiropyran scaffold. This finding was used to fabricate a time-sensitive information storage medium with tunable lifetimes of the encoded messages.
AU - Wang, Jinhua
AU - Avram, Liat
AU - Diskin-Posner, Yael
AU - Białek, Michał J.
AU - Stawski, Wojciech
AU - Feller, Moran
AU - Klajn, Rafal
ID - 13348
IS - 46
JF - Journal of the American Chemical Society
KW - Colloid and Surface Chemistry
KW - Biochemistry
KW - General Chemistry
KW - Catalysis
SN - 0002-7863
TI - Altering the properties of spiropyran switches using coordination cages with different symmetries
VL - 144
ER -
TY - JOUR
AB - Confining molecules within well-defined nanosized spaces can profoundly alter their physicochemical characteristics. For example, the controlled aggregation of chromophores into discrete oligomers has been shown to tune their optical properties whereas encapsulation of reactive species within molecular hosts can increase their stability. The resazurin/resorufin pair has been widely used for detecting redox processes in biological settings; yet, how tight confinement affects the properties of these two dyes remains to be explored. Here, we show that a flexible PdII6L4 coordination cage can efficiently encapsulate both resorufin and resazurin in the form of dimers, dramatically modulating their optical properties. Furthermore, binding within the cage significantly decreases the reduction rate of resazurin to resorufin, and the rate of the subsequent reduction of resorufin to dihydroresorufin. During our studies, we also found that upon dilution, the PdII6L4 cage disassembles to afford PdII2L2 species, which lacks the ability to form inclusion complexes – a process that can be reversed upon the addition of the strongly binding resorufin/resazurin guests. We expect that the herein disclosed ability of a water-soluble cage to reversibly modulate the optical and chemical properties of a molecular redox probe will expand the versatility of synthetic fluorescent probes in biologically relevant environments.
AU - Yanshyna, Oksana
AU - Białek, Michał J.
AU - Chashchikhin, Oleg V.
AU - Klajn, Rafal
ID - 13347
JF - Communications Chemistry
KW - Materials Chemistry
KW - Biochemistry
KW - Environmental Chemistry
KW - General Chemistry
TI - Encapsulation within a coordination cage modulates the reactivity of redox-active dyes
VL - 5
ER -
TY - JOUR
AB - Molecular recognition is at the heart of the noncovalent synthesis of supramolecular assemblies and, at higher length scales, supramolecular materials. In a recent publication in Nature, Stoddart and co-workers demonstrate that the formation of host-guest complexes can be catalyzed by one of the simplest possible catalysts: the electron.
AU - Gemen, Julius
AU - Klajn, Rafal
ID - 13351
IS - 5
JF - Chem
KW - Materials Chemistry
KW - Biochemistry (medical)
KW - General Chemical Engineering
KW - Environmental Chemistry
KW - Biochemistry
KW - General Chemistry
SN - 2451-9308
TI - Electron catalysis expands the supramolecular chemist’s toolbox
VL - 8
ER -
TY - JOUR
AB - Confinement within molecular cages can dramatically modify the physicochemical properties of the encapsulated guest molecules, but such host-guest complexes have mainly been studied in a static context. Combining confinement effects with fast guest exchange kinetics could pave the way toward stimuli-responsive supramolecular systems—and ultimately materials—whose desired properties could be tailored “on demand” rapidly and reversibly. Here, we demonstrate rapid guest exchange between inclusion complexes of an open-window coordination cage that can simultaneously accommodate two guest molecules. Working with two types of guests, anthracene derivatives and BODIPY dyes, we show that the former can substantially modify the optical properties of the latter upon noncovalent heterodimer formation. We also studied the light-induced covalent dimerization of encapsulated anthracenes and found large effects of confinement on reaction rates. By coupling the photodimerization with the rapid guest exchange, we developed a new way to modulate fluorescence using external irradiation.
AU - Gemen, Julius
AU - Białek, Michał J.
AU - Kazes, Miri
AU - Shimon, Linda J.W.
AU - Feller, Moran
AU - Semenov, Sergey N.
AU - Diskin-Posner, Yael
AU - Oron, Dan
AU - Klajn, Rafal
ID - 13350
IS - 9
JF - Chem
KW - Materials Chemistry
KW - Biochemistry (medical)
KW - General Chemical Engineering
KW - Environmental Chemistry
KW - Biochemistry
KW - General Chemistry
SN - 2451-9308
TI - Ternary host-guest complexes with rapid exchange kinetics and photoswitchable fluorescence
VL - 8
ER -
TY - JOUR
AB - We show that the optical properties of indigo carmine can be modulated by encapsulation within a coordination cage. Depending on the host/guest molar ratio, the cage can predominantly encapsulate either one or two dye molecules. The 1 : 1 complex is fluorescent, unique for an indigo dye in an aqueous solution. We have also found that binding two dye molecules stabilizes a previously unknown conformation of the cage.
AU - Yanshyna, Oksana
AU - Avram, Liat
AU - Shimon, Linda J. W.
AU - Klajn, Rafal
ID - 13353
IS - 21
JF - Chemical Communications
KW - Materials Chemistry
KW - Metals and Alloys
KW - Surfaces
KW - Coatings and Films
KW - General Chemistry
KW - Ceramics and Composites
KW - Electronic
KW - Optical and Magnetic Materials
KW - Catalysis
SN - 1359-7345
TI - Coexistence of 1:1 and 2:1 inclusion complexes of indigo carmine
VL - 58
ER -
TY - JOUR
AB - The mammalian hippocampal formation (HF) plays a key role in several higher brain functions, such as spatial coding, learning and memory. Its simple circuit architecture is often viewed as a trisynaptic loop, processing input originating from the superficial layers of the entorhinal cortex (EC) and sending it back to its deeper layers. Here, we show that excitatory neurons in layer 6b of the mouse EC project to all sub-regions comprising the HF and receive input from the CA1, thalamus and claustrum. Furthermore, their output is characterized by unique slow-decaying excitatory postsynaptic currents capable of driving plateau-like potentials in their postsynaptic targets. Optogenetic inhibition of the EC-6b pathway affects spatial coding in CA1 pyramidal neurons, while cell ablation impairs not only acquisition of new spatial memories, but also degradation of previously acquired ones. Our results provide evidence of a functional role for cortical layer 6b neurons in the adult brain.
AU - Ben Simon, Yoav
AU - Käfer, Karola
AU - Velicky, Philipp
AU - Csicsvari, Jozsef L
AU - Danzl, Johann G
AU - Jonas, Peter M
ID - 11951
JF - Nature Communications
KW - General Physics and Astronomy
KW - General Biochemistry
KW - Genetics and Molecular Biology
KW - General Chemistry
KW - Multidisciplinary
SN - 2041-1723
TI - A direct excitatory projection from entorhinal layer 6b neurons to the hippocampus contributes to spatial coding and memory
VL - 13
ER -
TY - JOUR
AB - Germline determination is essential for species survival and evolution in multicellular organisms. In most flowering plants, formation of the female germline is initiated with specification of one megaspore mother cell (MMC) in each ovule; however, the molecular mechanism underlying this key event remains unclear. Here we report that spatially restricted auxin signaling promotes MMC fate in Arabidopsis. Our results show that the microRNA160 (miR160) targeted gene ARF17 (AUXIN RESPONSE FACTOR17) is required for promoting MMC specification by genetically interacting with the SPL/NZZ (SPOROCYTELESS/NOZZLE) gene. Alterations of auxin signaling cause formation of supernumerary MMCs in an ARF17- and SPL/NZZ-dependent manner. Furthermore, miR160 and ARF17 are indispensable for attaining a normal auxin maximum at the ovule apex via modulating the expression domain of PIN1 (PIN-FORMED1) auxin transporter. Our findings elucidate the mechanism by which auxin signaling promotes the acquisition of female germline cell fate in plants.
AU - Huang, Jian
AU - Zhao, Lei
AU - Malik, Shikha
AU - Gentile, Benjamin R.
AU - Xiong, Va
AU - Arazi, Tzahi
AU - Owen, Heather A.
AU - Friml, Jiří
AU - Zhao, Dazhong
ID - 12130
JF - Nature Communications
KW - General Physics and Astronomy
KW - General Biochemistry
KW - Genetics and Molecular Biology
KW - General Chemistry
KW - Multidisciplinary
SN - 2041-1723
TI - Specification of female germline by microRNA orchestrated auxin signaling in Arabidopsis
VL - 13
ER -
TY - JOUR
AB - The inadequate understanding of the mechanisms that reversibly convert molecular sulfur (S) into lithium sulfide (Li2S) via soluble polysulfides (PSs) formation impedes the development of high-performance lithium-sulfur (Li-S) batteries with non-aqueous electrolyte solutions. Here, we use operando small and wide angle X-ray scattering and operando small angle neutron scattering (SANS) measurements to track the nucleation, growth and dissolution of solid deposits from atomic to sub-micron scales during real-time Li-S cell operation. In particular, stochastic modelling based on the SANS data allows quantifying the nanoscale phase evolution during battery cycling. We show that next to nano-crystalline Li2S the deposit comprises solid short-chain PSs particles. The analysis of the experimental data suggests that initially, Li2S2 precipitates from the solution and then is partially converted via solid-state electroreduction to Li2S. We further demonstrate that mass transport, rather than electron transport through a thin passivating film, limits the discharge capacity and rate performance in Li-S cells.
AU - Prehal, Christian
AU - von Mentlen, Jean-Marc
AU - Drvarič Talian, Sara
AU - Vizintin, Alen
AU - Dominko, Robert
AU - Amenitsch, Heinz
AU - Porcar, Lionel
AU - Freunberger, Stefan Alexander
AU - Wood, Vanessa
ID - 12208
JF - Nature Communications
KW - General Physics and Astronomy
KW - General Biochemistry
KW - Genetics and Molecular Biology
KW - General Chemistry
KW - Multidisciplinary
SN - 2041-1723
TI - On the nanoscale structural evolution of solid discharge products in lithium-sulfur batteries using operando scattering
VL - 13
ER -
TY - JOUR
AB - The development dynamics and self-organization of glandular branched epithelia is of utmost importance for our understanding of diverse processes ranging from normal tissue growth to the growth of cancerous tissues. Using single primary murine pancreatic ductal adenocarcinoma (PDAC) cells embedded in a collagen matrix and adapted media supplementation, we generate organoids that self-organize into highly branched structures displaying a seamless lumen connecting terminal end buds, replicating in vivo PDAC architecture. We identify distinct morphogenesis phases, each characterized by a unique pattern of cell invasion, matrix deformation, protein expression, and respective molecular dependencies. We propose a minimal theoretical model of a branching and proliferating tissue, capturing the dynamics of the first phases. Observing the interaction of morphogenesis, mechanical environment and gene expression in vitro sets a benchmark for the understanding of self-organization processes governing complex organoid structure formation processes and branching morphogenesis.
AU - Randriamanantsoa, S.
AU - Papargyriou, A.
AU - Maurer, H. C.
AU - Peschke, K.
AU - Schuster, M.
AU - Zecchin, G.
AU - Steiger, K.
AU - Öllinger, R.
AU - Saur, D.
AU - Scheel, C.
AU - Rad, R.
AU - Hannezo, Edouard B
AU - Reichert, M.
AU - Bausch, A. R.
ID - 12217
JF - Nature Communications
KW - General Physics and Astronomy
KW - General Biochemistry
KW - Genetics and Molecular Biology
KW - General Chemistry
KW - Multidisciplinary
SN - 2041-1723
TI - Spatiotemporal dynamics of self-organized branching in pancreas-derived organoids
VL - 13
ER -