@techreport{SchmidtEfimova, author = {Schmidt, Peer and Efimova, Anastasia}, title = {Thermal Characterization of Ionic Liquids}, publisher = {NETZSCH-Ger{\"a}tebau GmbH}, address = {Selb}, pages = {14 -- 17}, abstract = {Ionic liquids (ILs) are currently of high interest due to their high performance physicochemical properties over a wide temperature range of existence of the liquid state. Among the ionic liquids investigated, 1-alkyl-3-methylimidazolium halides were found generally preferred for their low melting points and ease of handling and preparation.}, language = {en} } @misc{WelsSchmidt, author = {Wels, Martin and Schmidt, Peer}, title = {Crystal growth of ternary phases with homogeneity range: Modeling and experiments}, series = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, volume = {642}, journal = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, number = {18}, issn = {1521-3749}, doi = {10.1002/zaac.201690018}, pages = {1066}, abstract = {Synthesizing crystals of ternary solid solutions M2Q3 (M=Bi, Q=Se, Te) with definite composition requires advanced knowledge on the phase relations in the system. By chemical vapor transport [1] the request of homogeneous crystallization can be fulfilled. The experimental scope gets supported by modeling. A phase diagram of the pseudobinary system generated with FactSage [2] (Fig. 1) provides the thermodynamic parameters of the miscibility gap respectively the solid solution. Additionally, these parameters are used to optimize the processes while chemical vapor transport with iodine [3]. The optimum transport conditions of ϑsource = 500 °C and ϑsink = 450 °C has been applied as for the synthesis of the binary compounds [4]. Both by modeling and experiments the congruent transport can be demonstrated, Fig. 2.}, language = {en} } @book{Schmidt, author = {Schmidt, Peer}, title = {Allgemeine Chemie, Teil 1: Atombau und Periodensystem}, publisher = {Springer Spektrum}, address = {Heidelberg [u.a.]}, isbn = {978-3-662-47347-4}, pages = {56}, abstract = {Aufbau der Atome und die Ordnung der chemischen Elemente im Periodensystem}, language = {de} } @book{SchmidtBinnewiesFinze, author = {Schmidt, Peer and Binnewies, Michael and Finze, Maik}, title = {Anorganische Chemie, Band 2: Gruppe 2, Gruppe 13}, edition = {1. Auflage}, publisher = {Springer}, address = {Heidelberg}, isbn = {978-3-662-47549-2}, pages = {61}, abstract = {Elemente der Gruppe 2 (Erdalkalimetalle); Elemente der Gruppe 13}, language = {de} } @book{SchmidtBinnewiesFinze, author = {Schmidt, Peer and Binnewies, Michael and Finze, Maik}, title = {Anorganische Chemie, Band 3: Gruppe 14, Ressourceneffizienz}, edition = {1. Auflage}, publisher = {Springer}, address = {Heidelberg}, isbn = {978-3-662-47561-4}, pages = {62}, abstract = {Elemente der Gruppe 14 (Tetrele); Strategien der Ressourceneffizienz}, language = {de} } @book{SchmidtBinnewiesFinze, author = {Schmidt, Peer and Binnewies, Michael and Finze, Maik}, title = {Anorganische Chemie, Band 4: Gruppen 15 und 16}, edition = {1. Auflage}, publisher = {Springer}, address = {Heidelberg}, isbn = {978-3-662-47565-2}, pages = {70}, abstract = {Gruppe 15 (Pnikogene); Gruppe 16 (Chalkogene)}, language = {de} } @book{SchmidtBinnewiesFinze, author = {Schmidt, Peer and Binnewies, Michael and Finze, Maik}, title = {Anorganische Chemie, Band 5: Gruppen 17 und 18}, edition = {1. Auflage}, publisher = {Springer}, address = {Heidelberg}, isbn = {978-3-662-47547-8}, pages = {57}, abstract = {Gruppe 17 (Halogene); Gruppe 18 (Edelgase)}, language = {de} } @book{BinnewiesFinzeJaeckeletal., author = {Binnewies, Michael and Finze, Maik and J{\"a}ckel, Manfred and Schmidt, Peer and Willner, Helge and Rayner-Canham, Geoff}, title = {Allgemeine und Anorganische Chemie}, edition = {3., vollst{\"a}ndig {\"u}berarbeitetet Auflage}, publisher = {Springer}, address = {Heidelberg}, isbn = {978-3-662-45066-6}, pages = {965}, abstract = {Der Lehrstoff der Allgemeinen und Anorganischen Chemie f{\"u}r die ersten zwei Semester des Chemiestudiums. Ausgewogene Stoffdarstellung mit vielen Einblicken in hochaktuelle Themen und Anwendungen. Mit zahlreichen neuen Inhalten und Aktualisierungen, etwa zu großtechnischen Verfahren, zur zunehmenden Bedeutung seltener Elemente wie Gallium und Indium f{\"u}r Hightech-Produkte, zu Rohstoffen f{\"u}r Zukunftstechnologien, zum Schweißen und L{\"o}ten, zu Magnetwerkstoffen und W{\"a}rmespeichern. Die Nomenklatur ist an die aktuellen IUPAC-Regeln angepasst.}, language = {de} } @book{Schmidt, author = {Schmidt, Peer}, title = {Allgemeine Chemie, Teil 2: Chemische Bindungen 1}, publisher = {Springer Spektrum}, address = {Heidelberg [u.a.]}, isbn = {978-3-662-47516-4}, pages = {54}, abstract = {Prinzipien der chemischen Bindung in Metallen und in Ionenkristallen}, language = {de} } @book{Schmidt, author = {Schmidt, Peer}, title = {Allgemeine Chemie, Teil 3: Chemische Bindungen 2}, publisher = {Springer Spektrum}, address = {Heidelberg [u.a.]}, isbn = {978-3-662-47563-8}, pages = {56}, abstract = {Konzepte zur Beschreibung der Struktur und chemischen Bindung in Molek{\"u}len}, language = {de} } @book{Schmidt, author = {Schmidt, Peer}, title = {Allgemeine Chemie, Teil 4: Thermodynamik und Kinetik}, publisher = {Springer Spektrum}, address = {Heidelberg [u.a.]}, isbn = {978-3-662-47518-8}, pages = {56}, abstract = {Thermodynamische Kenngr{\"o}ßen zu Beschreibung chemischer Gleichgewichte und zeitabh{\"a}ngige Einstellung des chemischen Gleichgewichts}, language = {de} } @book{SchmidtNilges, author = {Schmidt, Peer and Nilges, Tom}, title = {Allgemeine Chemie, Teil 5: Wissenschaftliches Arbeiten}, publisher = {Springer Spektrum}, address = {Berlin [u.a.]}, isbn = {978-3-662-47539-3}, pages = {37}, abstract = {Prinzipien des wissenschaftlichen Arbeitens und Methodik zur Erstellung von Protokollen, Kurzberichten, Projektberichten und wissenschaftlichen Publikationen}, language = {de} } @misc{SchmidtHohmannNilgesetal., author = {Schmidt, Peer and Hohmann, Andrea and Nilges, Tom and K{\"o}pf, Marianne and Weihrich, Richard}, title = {Synthesis of Element Allotropes of Arsenic and Phosphorus by Application of Electromotive Series of Solids}, series = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, volume = {640}, journal = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, number = {11}, issn = {1521-3749}, doi = {10.1002/zaac.201490026}, pages = {2386}, abstract = {Calculation of electromotive series of solids allows easy prediction of reaction pathways[1]. Using the electromotive series of systems As-P-O and As-P-X (X = F, Cl, Br, I) the formation of element allotropes via the oxide and halide compounds in thermite type reactions can be deduced: phosphorous will reduce the arsenic oxides to elemental arsenic, forming grey or black allotrope, depending on reaction mixture composition.}, language = {en} } @misc{WolfDoertStolzeetal., author = {Wolf, Adrian and Doert, Thomas and Stolze, Karoline and Schmidt, Peer}, title = {Modeling of Chemical Vapor Transport of Uranium Phosphide Telluride UPTe}, series = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, volume = {640}, journal = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, number = {11}, issn = {1521-3749}, doi = {10.1002/zaac.201490026}, pages = {2374}, abstract = {The crystallization mechanism of uranium phosphide telluride UPTe by chemical vapor transport reaction [1] is presented based on thermodynamic modelling using TRAGMIN program. Evaluation of standard data of all expected species was performed by modeling of the binary phase diagrams U/Te and U/P. Data of UPTe were deduced from known phosphide tellurides[2,3]. Identifying the viable composition area within the quaternary system U/P/Te/I the temperature depending transport equilibria could be obtained.}, language = {en} } @misc{HeinemannSchmidt, author = {Heinemann, Robert and Schmidt, Peer}, title = {Vapor Transport Investigations using the High-temperature Gas-balance}, series = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, volume = {640}, journal = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, number = {11}, issn = {1521-3749}, doi = {10.1002/zaac.201490026}, pages = {2338}, abstract = {The High-temperature Gas-balance (HTGB[1]) has been established as a new method for investigations of heterogeneous phase equilibria with volatile components [1,2]. This equipment is notably well suited to analyze reversible heterogeneous equilibria which occur during chemical vapor transport reactions (CVT[3]). Experimental proof has been furnished by vapor transports of germanium and germanium(II) telluride using iodine as a transport addition. Initially the sublimation of iodine has been observed (section a - Fig. 1). The formation of GeI4(g) as the actual transport agent follows (b). Finally, the transport reaction occurs under reversible formation GeI2(g) (c).}, language = {en} } @misc{Schmidt, author = {Schmidt, Peer}, title = {Rational Synthesis Design by Application of Electromotive Series of Solid Materials}, series = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, volume = {640}, journal = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, number = {11}, issn = {1521-3749}, doi = {10.1002/zaac.201490026}, pages = {2326}, abstract = {The concept of Electromotive Series of Solids presents an easy tool for prediction and interpretation of red-ox processes of inorganic solid materials. Thus, a rational synthesis design succeeds with low effort compared to complex thermodynamic considerations. The principle has been applied and validated for interpretation of known chemical systems as well for the development of new systems and processes.}, language = {en} } @misc{EfimovaHubrigPfuetzneretal., author = {Efimova, Anastasia and Hubrig, Grit and Pf{\"u}tzner, Linda and Schmidt, Peer}, title = {Thermal Stability of Alkyl-Imidazolium-Ionic Liquids}, series = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, volume = {640}, journal = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, number = {11}, issn = {1521-3749}, doi = {10.1002/zaac.201490026}, pages = {2391}, abstract = {The thermochemical behavior of two groups of ionic liquids (ILs), 1-ethyl-3-methylimidazolium [EtMeIm] and 1-butyl-3-methylimidazolium [BuMeIm] halides (Cl, Br and I) was investigated for their crystalline and liquid states in the temperature range from -100 °C to 600 °C using DSC and thermogravimetric analysis (TGA). Some investigated ILs exhibit significant subcooling effect and the glass state formation [1]. The decomposition mechanism has been identified by means of TGA with coupled mass spectrometry (MS). All investigated ILs decompose with a total mass loss of about 100 \% in the temperature range of Tonset from 230 to 290 °C (Fig. 1). By complete degradation of IL, dominant fragments CnH2n+1+, CnH2n+, CnHn+, NHn+, and the respective alkyl halides (X = Cl, Br, I) are formed.}, language = {en} } @book{SchmidtBinnewiesFinze, author = {Schmidt, Peer and Binnewies, Michael and Finze, Maik}, title = {Anorganische Chemie, Band 1: Elemente, Wasserstoff, Gruppe 1}, edition = {1. Auflage}, publisher = {Springer}, address = {Heidelberg}, isbn = {978-3-662-47557-7}, pages = {52}, abstract = {Entstehung und Vorkommen der chemischen Elemente; periodische Eigenschaften der Elemente; Wasserstoff; Elemente der Gruppe 1 (Alkalimetalle)}, language = {de} } @misc{PielnhoferBachhuberSchmidtetal., author = {Pielnhofer, Florian and Bachhuber, Frederik and Schmidt, Peer and Nilges, Tom and Weihrich, Richard}, title = {Mit DFT-Modellierungen zu neuen Polyanionenverbindungen}, series = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, volume = {638}, journal = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, number = {10}, doi = {10.1002/zaac.201204137}, pages = {S. 1634}, abstract = {Verbindungen mit ionischen Baueinheiten erweisen sich als geeignete Materialien zur Energie- und Ressourcennutzung. Beispiele sind Li-Elektrodenmaterialien oder neue Thermoelektrika, die aufgrund ihrer Teilstrukturen schaltbar werden. Das Design neuer funktionaler Materialien verlangt dabei nach einem grundlegenden Verst{\"a}ndnis von Struktur-Eigenschafts-Beziehungen, metastabilen Strukturen und Umwandlungen. Dies bedarf des Einsatzes kombinierter experimenteller und theoretischer Methoden. Zur systematischen Erforschung metastabiler Strukturen wurde j{\"u}ngst das Konzept der Strukturvorhersage in Energielandschaften mit ab initio Methoden auf das System P1-xAsx angewandt und mit experimentellen Messungen verkn{\"u}pft. Im n{\"a}chsten Schritt wurden Verbindungen mit ionischen Teilstrukturen des As, Sb, Se und Te untersucht. Modellhaft wurden nun Zintl-Systemen wie IrPTe und PtSnTe neue m{\"o}gliche metastabile Strukturen identifiziert und auf Funktionalisierungen untersucht.}, language = {de} } @misc{NilgesOstersSchmidtetal., author = {Nilges, Tom and Osters, Oliver and Schmidt, Peer and Sch{\"o}neich, Michael and Weihrich, Richard and Bachhuber, Frederik}, title = {Untersuchungen zur Bildung von schwarzem Arsen}, series = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, volume = {636}, journal = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, number = {11}, doi = {10.1002/zaac.201008019}, pages = {S. 46}, abstract = {Das Mineralisatorkonzept f{\"u}r Polypniktide, basierend auf PbI2 als Mineralisator, wurde erfolgreich zur Synthese der festen L{\"o}sung von ortho-rhombischem, schwarzen As1-xPx eingesetzt (x = 0.17-1). Die Zellparameter von As0.83P0.17 sind identisch mit den Literaturwerten des As(schwarz). Aus Pulver- und Einkristalldaten bei variabler Zusammensetzung ist es m{\"o}glich, das Zellvolumen und die Gitterparameter von reinem, schwarzen Arsen abzuleiten. Die Analyse der Phasenbildung basiert auf der Bestimmung der Gleichgewichtsdr{\"u}cke der Intermediate Au2P3 und Asgrau sowie von PbI2 im Vergleich zu As1-xPx(schwarz): Die Kondensation erfolgt unterhalb 600 °C aus einer komplexen Gasphase (u.a. AsnP4-n).}, language = {de} } @misc{SchoeneichLorenzBawohletal., author = {Sch{\"o}neich, Michael and Lorenz, Tobias and Bawohl, Melanie and Nilges, Tom and Schmidt, Peer}, title = {Phase Formation in the System Hg/P/I Induced by Evaporation Pressure}, series = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, volume = {636}, journal = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, number = {11}, doi = {10.1002/zaac.201009042}, pages = {S. 2070}, language = {en} } @techreport{PinnauEfimovaSchmidt, author = {Pinnau, Sebastian and Efimova, Anastasia and Schmidt, Peer}, title = {Identifikation technischer Salze als Latentspeichermaterialien im Temperaturbereich von 4 bis 15 °C und deren Verkapselung: Abschlussbericht}, address = {Dresden}, doi = {10.2314/GBV:786966173}, pages = {92}, abstract = {Der Einsatz von thermischen Speichern erlaubt eine bessere Lastanpassung von Erzeugeranlagen zur Geb{\"a}udeklimatisierung sowie eine Optimierung des Betriebsregimes unter energetischen Gesichtspunkten. F{\"u}r solche Anwendungsf{\"a}lle k{\"o}nnen Latentw{\"a}rmespeicher zum Einsatz kommen, bei denen {\"u}blicherweise der Schmelz- und Erstarrungsvorgang sogenannter Phasenwechselmaterialien (Phase Change Materials, PCM) ausgenutzt wird. F{\"u}r die Anwendungstemperaturbereiche der Klimatisierung von etwa 4 °C bis 15 °C und f{\"u}r die K{\"u}hlung bis etwa 25 °C ist die Auswahl an Reinstoffen mit einer passenden Schmelztemperatur sehr begrenzt. Durch die Bildung von eutektischen Gemischen aus zwei oder mehr Komponenten - die {\"a}hnlich wie Reinstoffe einen scharfen Schmelzpunkt aufweisen - kann die Bandbreite an potentiellen PCM's f{\"u}r diesen Temperaturbereich vergr{\"o}ßert werden. F{\"u}r die genannten Temperaturbereiche werden vorzugsweise anorganische Salzhydrate als potentielle Speichermedien betrachtet, da diese gegen{\"u}ber organischen Substanzen h{\"a}ufig gr{\"o}ßere Schmelzenthalpien und geringere Kosten aufweisen.}, language = {de} } @misc{SchoeneichSchmidt, author = {Sch{\"o}neich, Michael and Schmidt, Peer}, title = {Kinetics of phase formation in solid - gas reactions: Iron and Arsenic}, series = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, volume = {638}, journal = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, number = {10}, doi = {10.1002/zaac.201204026}, pages = {S. 1579}, abstract = {Based on the experience of thermo-chemical studies on a High-Temperature Gas-Balance a time dependent analysis has been developed for the investigations of the kinetics of solid-gas reactions. The course of solid-gas reactions can be examined unambiguously by separation of the initial solids. By this setup the visualization of different stages of solid-gas reaction (vaporization, phase formation) becomes feasible. Time dependent analysis of the formation of FeAs results in an assignment of the underlying principles of kinetics derived from the conversion factor α.}, language = {en} } @misc{SchmidtSchoeneichNilgesetal., author = {Schmidt, Peer and Sch{\"o}neich, Michael and Nilges, Tom and Weihrich, Richard}, title = {Identification of Metastable States in Heterogeneous Phase Formation}, series = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, volume = {638}, journal = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, number = {10}, doi = {10.1002/zaac.201204134}, pages = {S. 1633}, language = {en} } @techreport{SchmidtEfimova, author = {Schmidt, Peer and Efimova, Anastasia}, title = {Kristallisationsverhalten von Phasenwechselmaterialien als Latentw{\"a}rmespeicher (KristallLaW): Abschlussbericht}, publisher = {BTU Cottbus - Senftenberg, Fachgebiet Anorganische Chemie}, address = {Senftenberg}, doi = {10.2314/GBV:884496287}, pages = {44}, abstract = {Phasenwechselmaterialien (PCM) sind chemische Verbindungen oder deren Mischungen, die bei einer definierten Temperatur schmelzen bzw. erstarren. Der zyklische Einsatz von W{\"a}rmespeichern erm{\"o}glicht den Ausgleich von {\"U}berlasten f{\"u}r den Bedarf oder den „Abfall" von W{\"a}rme sowie die Vergleichm{\"a}ßigung von W{\"a}rmeprofilen. Bestehende anorganische Materialien weisen {\"u}berwiegend Einschr{\"a}nkungen bez{\"u}glich der Anforderungen an eine geringe Hysterese von Aufheizung und Abk{\"u}hlung auf. Das Maß der Unterk{\"u}hlung der Schmelze sowie ein zyklenstabiler W{\"a}rmeaustausch kann aber durch Zus{\"a}tze als Kristallisationshilfen (Keimbildner) gesteuert werden. Im vorliegenden Bericht werden die Keimbildung und Kristallisation von Phasenwechselmaterialien unter folgenden Gesichtspunkten diskutiert: Methoden der Thermischen Analyse zur Untersuchung der thermochemischen Eigenschaften von PCM, thermochemische Eigenschaften anorganischer Salze und Salzhydrate als PCM, dominierende Kristallstrukturen und Strukturmotive anorganischer Salze und Salzhydrate als PCM, dominierende Kristallstrukturen und Strukturmotive anorganischer Stoffe als homogener und heterogener Keimbildner, {\"A}nderung der thermochemischen Eigenschaften von PCM bei Zusatz von Keimbildnern, geeignete Konzentrationsbereiche von Keimbildnern, Homogenit{\"a}t/Segregation von Phasen.}, language = {de} } @misc{BinnewiesSchmidtSchmidt, author = {Binnewies, Michael and Schmidt, Marcus and Schmidt, Peer}, title = {Chemical Vapor Transport Reactions - Arguments for Choosing a Suitable Transport Agent}, series = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, volume = {643}, journal = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, number = {21}, issn = {1521-3749}, doi = {10.1002/zaac.201700055}, pages = {1295 -- 1311}, abstract = {A variety of processes of crystal growth proceeds via the gas phase. If the initial solid material is volatilized in a heterogeneous reaction under presence of a gaseous reactant, the transport agent, the term Chemical Vapor Transport Reaction (CVT) is applied. Crystallization processes by CVT are known for both elements, intermetallics, binary and complex oxides, halides, chalcogenides, and pnictides. Even if the formation of volatile halides is a common feature of almost all vapor transport reactions, significant differences are there concerning the choice of a suitable transport agent depending on the nature of the initial solid phase. Actually, the appropriateness of transport agents for the respective transport reaction can be described in a thermodynamic way. Besides some basic principles for systematic evaluation more practical recommendations for suitable experimental conditions are given for CVT of different classes of inorganic materials.}, language = {en} } @book{BinnewiesFinzeRadiusetal., author = {Binnewies, Michael and Finze, Maik and Radius, Udo and Schmidt, Peer}, title = {Anorganische Chemie, Band 6: Nebengruppen - Teil 1}, edition = {1. Auflage}, publisher = {Springer}, address = {Heidelberg}, isbn = {978-3-662-55904-8}, pages = {61}, abstract = {Stellung der Nebengruppenelemente im Periodensystem, Gruppeneigenschaften, Gewinnung der Metalle, die Nebengruppen (Gruppen 3 bis 12)}, language = {de} } @book{BinnewiesFinzeRadiusetal., author = {Binnewies, Michael and Finze, Maik and Radius, Udo and Schmidt, Peer}, title = {Anorganische Chemie, Band 7: Nebengruppen - Teil 2}, edition = {1. Auflage}, publisher = {Springer}, address = {Heidelberg}, isbn = {978-3-662-55906-2}, pages = {64}, abstract = {Koordinationschemie,Konzepte der chemischen Bindung in Komplexverbindungen}, language = {de} } @book{BinnewiesFinzeRadiusetal., author = {Binnewies, Michael and Finze, Maik and Radius, Udo and Schmidt, Peer}, title = {Anorganische Chemie, Band 8: Metallorganische Chemie der {\"U}bergangsmetalle}, edition = {1. Auflage}, publisher = {Springer}, address = {Heidelberg}, isbn = {978-3-662-56030-3}, pages = {87}, language = {de} } @book{BinnewiesFinzeRadiusetal., author = {Binnewies, Michael and Finze, Maik and Radius, Udo and Schmidt, Peer}, title = {Anorganische Chemie, Band 9: Festk{\"o}rperchemie}, edition = {1. Auflage}, publisher = {Springer}, address = {Heidelberg}, isbn = {978-3-662-47577-5}, pages = {91}, abstract = {Beschreibung kristalliner Strukturen, Strukturen anorganischer Festk{\"o}rper und Methoden zur Synthese und Kristallz{\"u}chtung}, language = {de} } @book{BinnewiesFinzeRadiusetal., author = {Binnewies, Michael and Finze, Maik and Radius, Udo and Schmidt, Peer}, title = {Anorganische Chemie, Band 10: Lanthanoide}, edition = {1. Auflage}, publisher = {Springer}, address = {Heidelberg}, isbn = {978-3-662-47543-0}, pages = {28}, abstract = {Vorkommen, Gewinnung und Verbindungen der Lanthanoide - Anwendungen der Lanthanoide und ihrer Verbindungen}, language = {de} } @misc{EfimovaVargaMatuscheketal., author = {Efimova, Anastasia and Varga, Janos and Matuschek, Georg and Saraji-Bozorgzad, Mohammad R. and Denner, Thomas and Zimmermann, Ralf and Schmidt, Peer}, title = {Thermal Resilience of Imidazolium-Based Ionic Liquids—Studies on Short- and Long-Term Thermal Stability and Decomposition Mechanism of 1-Alkyl-3-methylimidazolium Halides by Thermal Analysis and Single-Photon Ionization Time-of-Flight Mass Spectrometry}, series = {Journal of Physical Chemistry B}, volume = {122}, journal = {Journal of Physical Chemistry B}, number = {37}, doi = {10.1021/acs.jpcb.8b06416}, pages = {8738 -- 8749}, abstract = {Ionic liquids are often considered as green alternatives of volatile organic solvents. The thermal behavior of the ionic liquids is relevant for a number of emerging large-scale applications at elevated temperature. Knowledge about the degradation products is indispensable for treatment and recycling of the used ionic liquids. The objective of this paper was an investigation of the short- and long-term stability of several 1-alkyl-3-methylimidazolium halides, determination of the degradation products, and the elucidation of their decomposition patterns and structure-stability relations. Short-term stability and mechanism of thermal degradation were investigated by a self-developed, innovative thermal analysis single-photon ionization time-of-flight mass spectrometry device with Skimmer coupling. The applied technology provides real-time monitoring of the forming species and allows tracing their change during the course of the decomposition. Therein, the almost fragment-free soft ionization with vacuum ultraviolet photons plays a crucial role. We have detected unfragmented molecules whose formation was only assumed by electron ionization. Nevertheless, the main decomposition products of the selected ionic liquids were alkyl imidazoles, alkenes, alkyl halides, and hydrogen halides. From the decomposition products, we have deduced the fragmentation patterns and discussed their interrelation with the length of the alkyl chain and the type of the halide anion. Our results did not suggest the evaporation of the investigated ionic liquids prior to their decomposition under atmospheric conditions. Long-term thermal stability and applicability were determined based on thermogravimetric analysis evaluated with a kinetic model. Thus, the time-dependent maximum operation temperature (MOT) for the respective ionic liquids has been calculated. As a rule, the short-term stability overestimates the long-term decomposition temperatures; the calculated MOT are significantly lower (at least 100 K) than the standardly obtained decomposition temperatures.}, language = {en} } @incollection{NilgesSchmidtWeihrich, author = {Nilges, Tom and Schmidt, Peer and Weihrich, Richard}, title = {Phosphorus: The Allotropes, Stability, Synthesis, and Selected Applications}, series = {Encyclopedia of Inorganic and Bioinorganic Chemistry}, booktitle = {Encyclopedia of Inorganic and Bioinorganic Chemistry}, editor = {Scott, Robert A.}, edition = {2. Auflage}, publisher = {John Wiley Sons}, address = {Hoboken, US}, isbn = {978-1-119-95143-8}, doi = {10.1002/9781119951438.eibc2643}, pages = {1 -- 19}, abstract = {Phosphorus, first found in the seventeenth century, played an important role in the definition of the element term by Lavoisier and thus shaped the beginning of the era of modern chemistry. It was discovered for the first time in the most unstable crystalline modification—the white phosphorus. Today, a variety of experimentally proven allotropes are known. The most common allotropes, such as black, violet, and fibrous phosphorus, are described here with respect to their synthesis, crystal structures, thermal, and thermodynamic properties. Besides, more than 50 crystalline allotropes have been predicted, and their stabilities have been estimated using quantum-chemical methods. This way, phosphorus becomes one of the most structurally variable elements of the periodic table. In this article, some of the most reasonable and sophisticated calculations are presented. The applications of elemental phosphorus are mainly connected with its semiconducting properties. Thus, the development of current applications is strongly related to new synthesis methods for direct preparation of individual, phase pure allotropic forms of phosphorus. The past decade supplied basic results on the formation of black phosphorus and other modifications, primarily using the mineralizer concept. Related to graphene and other two-dimensional, layered structures, phosphorene is of drastically rising interest. The pertinent modifications are characterized by corrugated arrangement of six-membered P-rings, where both the boat conformation and the chair conformation are known. The application of phosphorene is in a jumping evolution. Currently, phosphorene is already in use in manifold ways, including as a sensor, optical device, transistor, energy-conversion material, and supercapacitor material.}, language = {en} } @misc{GroenkeSchmidtValldoretal., author = {Gr{\"o}nke, Martin and Schmidt, Peer and Valldor, Martin and Oswald, Steffen and Wolf, Daniel and Lubk, Axel and B{\"u}chner, Bernd and Hampel, Silke}, title = {Chemical vapor growth and delamination of α-RuCl3 nanosheets down to the monolayer limit}, series = {Nanoscale}, volume = {10}, journal = {Nanoscale}, number = {40}, issn = {2040-3372}, doi = {10.1039/C8NR04667K}, pages = {19014 -- 19022}, abstract = {2D layered honeycomb magnet α-ruthenium(III) chloride (α-RuCl3) is a promising candidate to realize a Kitaev spin model. As alteration of physical properties on the nanoscale is additionally intended, new synthesis approaches to obtain phase pure α-RuCl3 nanocrystals have been audited. Thermodynamic simulations of occurring gas phase equilibria were performed and optimization of synthesis conditions was achieved based on calculation results. Crystal growth succeeded via chemical vapor transport (CVT) in a temperature gradient of 973 K to 773 K on YSZ substrates. Single crystal sheets of high crystallinity with heights ≤ 30 nm were obtained via pure CVT. The crystal properties were characterized by means of optical and electron microscopy, AFM, SAED, micro-Raman and XPS proving their composition, morphology, crystallinity and phase-purity. A highlight of our study is the successful individualization of nanocrystals and the delamination of nanosheets on YSZ substrates down to the monolayer limit (≤ 1 nm) which was realized by means of substrate exfoliation and ultrasonication in a very reproducible way.}, language = {en} } @misc{PoddigDonathGebaueretal., author = {Poddig, Hagen and Donath, Tom and Gebauer, Paul and Finzel, Kati and Kohout, Miroslav and Wu, Yuandong and Schmidt, Peer and Doert, Thomas}, title = {Rare Earth Metal Polytellurides RETe1.8 (RE = Gd, Tb, Dy) - Directed Synthesis, Crystal and Electronic Structures, and Bonding Features}, series = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, volume = {644}, journal = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, number = {24}, issn = {1521-3749}, doi = {10.1002/zaac.201800382}, pages = {1886 -- 1896}, abstract = {Single crystals of the polytellurides RETe1.8 of gadolinium, terbium, and dysprosium were prepared by chemical vapor transport and alkali metal halide flux reactions. To determine proper synthesis conditions for the desired target composition, the binary phase diagram Gd-Te was evaluated by CalPhaD methods. The compounds are isostructural to SmTe1.8 and crystallize in space group P4/n (no. 85) with lattice parameters of a = 966.10(4), 960.00(3), and 957.33(2) pm and c = 1794.15(10), 1785.77(6), and 1779.38(5) pm for GdTe1.8, TbTe1.8 and DyTe1.8, respectively. The structures consist of puckered [RETe] double slabs and planar telluride layers composed of Te2 dumbbells and linear Te3 units in accordance with ELI-D based bonding analyses. The latter can be understood as a Te3(4-) anion. GdTe1.8 is a semiconductor with a bandgap of 0.19 eV/0.17 eV (experimental / calculated). Magnetization data confirm trivalent RE ions and indicate antiferromagnetic order at T(N) = 12 K for TbTe1.8 and T(N) = 9.8 K for DyTe1.8, whereas GdTe1.8 remains paramagnetic down to 2 K.}, language = {en} } @misc{KniesKaiserLeAnhetal., author = {Knies, Maximilian and Kaiser, Martin and L{\^e} Anh, Mai and Efimova, Anastasia and Doert, Thomas and Ruck, Michael}, title = {Low-Temperature Ordering in the Cluster Compound (Bi₈)Tl[AlCl₄]₃}, series = {Inorganics}, volume = {7}, journal = {Inorganics}, number = {4}, doi = {10.3390/inorganics7040045}, pages = {1 -- 9}, abstract = {The reaction of Bi, BiCl₃, and TlCl in the ionic liquid [BMIm]Cl·4AlCl₃ (BMIm = 1-n-butyl-3-methylimidazolium) at 180 °C yielded air-sensitive black crystals of (Bi₈)Tl[AlCl₄]₃. X-ray diffraction on single crystals at room temperature revealed a structure containing [Tl(AlCl₄)₃]∞12- strands separated by isolated Bi₈²⁺ square antiprisms. The thallium(I) ion is coordinated by twelve Cl⁻ ions of six [AlCl₄]⁻ groups, resulting in a chain of face-sharing [TlCl₁₂]¹¹⁻ icosahedra. The Bi₈²⁺ polycation is disordered, simulating a threefold axis through its center and overall hexagonal symmetry (space group P6₃/m). Slowly cooling the crystals to 170 K resulted in increased order in the Bi₈ cluster orientations. An ordered structure model in a supercell with a' = 2a, b' = 2b, c' = 3c and the space group P6₅ was refined. The structure resembles a hexagonal perovskite, with complex groups in place of simple ions.}, language = {en} } @misc{ScholzSchoeneichSchmidt, author = {Scholz, Tanja and Sch{\"o}neich, Michael and Schmidt, Peer}, title = {Understanding Solid-State Phase-Formation Processes by Usingthe High-Temperature Gas Balance: The Example of Zr₂PTe₂}, series = {European Journal of Inorganic Chemistry}, journal = {European Journal of Inorganic Chemistry}, number = {21}, doi = {10.1002/ejic.201900281}, pages = {2577 -- 2582}, abstract = {Inorganic solid-state synthesis with phosphorus and tellurium requires a careful control of the reaction parameters because of the high volatility of the components. This initial disadvantage can be used as a benefit for the investigation of phase formation mechanisms by analyzing the individual vapor pressure behavior. The high-temperature gas-balance is introduced as a device for detection of heterogeneous solid-gas equilibria in closed reaction systems. The experimentally challenging synthesis of the phosphide telluride Zr₂PTe₂ is examined as a model system: optimized synthesis runs at lower temperatures (ϑ = 650 °C) in a faster time, while the quantity as well as the crystalline powder quality is increased. A stepwise solid-solid reaction of zirconium and tellurium according to Ostwald's rule of stages and the shrinking core model is revealed while phosphorus sublimes and subsequently condenses to react to the ternary compound. Additional phenomena such as melting, expansion, and mechanical instabilities can be observed that broaden the possibilities of the gas- balance.}, language = {en} } @misc{GroenkePohfleppSchmidtetal., author = {Gr{\"o}nke, Martin and Pohflepp, Danny and Schmidt, Peer and Valldor, Martin and Oswald, Steffen and Wolf, Daniel and Hao, Qi and Steiner, Udo and B{\"u}chner, Bernd and Hampel, Silke}, title = {Simulation and synthesis of alpha-MoCl₃ nanosheets on substrates by short time chemical vapor transport}, series = {Nano-Structures \& Nano-Objects}, journal = {Nano-Structures \& Nano-Objects}, number = {19}, issn = {2352-507X}, doi = {10.1016/j.nanoso.2019.100324}, pages = {1 -- 7}, abstract = {Alpha-molybdenum(III) chloride (MoCl₃) belongs to layered van-der-Waals materials, which are in focus to exhibit interesting properties due to their weak chemical and magnetic interactions. Especially the structure of alpha-MoCl₃ has been discussed in terms of symmetry breaking dimerization of Mo atoms at room temperature, which might led to exotic ground states. By exploiting the 2D materials characteristics, an investigation of physical properties on the nanoscale is intended. We herein demonstrate the probably first approach to synthesize phase pure, as-grown alpha-MoCl₃ few-layer nanosheets by means of a pure short time chemical vapor transport (CVT) process. Vapor growth benefits from a one-step deposition of high crystalline alpha-MoCl₃ nanosheets without stacking faults on a substrate. Thus, mostly applied subsequent delamination, associated with the introduction of structural defects, becomes redundant. According to the CVT process thermodynamic simulations of gas phase equilibria have been performed and the synthesis conditions could be optimized based on the calculation results. By CVT the as-grown nanolayers are deposited on sapphire (Al₂O₃) substrates by applying a temperature gradient of 70 K from 743 K to 673 K. Single crystalline sheets with thicknesses ≤75 nm down to five layer (3 nm) could be obtained by using a pure CVT process. According to the deposited nanostructures we approve the desired composition, morphology, phase purity and high crystallinity by using several microscopy and spectroscopy techniques. Furthermore, we show micro-RAMAN measurements which hint at a slight increase in phonon energies for nanosheets in comparison to the corresponding bulk phase.}, language = {en} } @misc{GroenkeArroziBronkallaetal., author = {Gr{\"o}nke, Martin and Arrozi, Ubed S. F. and Bronkalla, Nadine and Schmidt, Peer and Valldor, Martin and Oswald, Steffen and Woodcock, Thomas G. and Eckert, Victoria and Hao, Qi and Pl{\"u}schke, Laura and Lederer, Albena and Nielsch, Kornelius and B{\"u}chner, Bernd and Kaskel, Stefan and Hampel, Silke}, title = {Layered α-TiCl₃: Microsheets on YSZ Substrates for Ethylene Polymerization with Enhanced Activity}, series = {Chemistry of Materials}, volume = {31}, journal = {Chemistry of Materials}, number = {14}, doi = {10.1021/acs.chemmater.9b01818}, pages = {5305 -- 5313}, abstract = {The transition metal halide α-titanium(III) chloride (α-TiCl₃) is a layered two-dimensional compound and a well-established Ziegler-Natta catalyst for the polymerization of ethylene. A new synthesis technique is used to obtain thin sheets of α-TiCl₃ that show exceptional physical properties in contrast to their bulk counterparts, due to an enlarged surface-to-volume ratio. Chemical vapor transport (CVT) of α-titanium(III) chloride directly on substrates results in microsheets that exhibit an improved catalytic effect. For rational planning of synthesis conditions, thermodynamic simulations of occurring gas-phase equilibria were performed. Based on these calculation results, crystal growth was achieved by adding GaCl₃via pure short term CVT in a temperature gradient of 700-600 K on yttrium-stabilized zirconia (YSZ) substrates. Phase pure, as-grown, single crystal sheets with high crystallinity and a thickness of around 4 μm were obtained. These thin sheets of α-TiCl₃ on YSZ substrates were implemented as catalysts for the ethylene polymerization reaction. A significant improvement of catalytic activity of 16\% was achieved, probably due to an increased surface-to-volume ratio. As a highlight, the as-grown microsheets were exfoliated subsequently to a thickness lower than 200 nm and an even higher catalytic activity of up to 24\% was confirmed experimentally due to delamination effects. This is the first time that an improved catalytic effect of α-TiCl₃ is observed as a result of downscaling from bulk to microsheets by CVT.}, language = {en} } @book{Schmidt, author = {Schmidt, Peer}, title = {Allgemeine Chemie}, edition = {1. Auflage}, publisher = {Springer-Spektrum}, address = {Heidelberg}, isbn = {978-3-662-57846-9}, pages = {268}, abstract = {Atombau, Konzepte der Chemischen Bindung sowie Thermodynamische Kenngr{\"o}ßen zu Beschreibung chemischer Gleichgewichte und zeitabh{\"a}ngige Einstellung des chemischen Gleichgewichts}, language = {de} } @misc{GroenkeBuschbeckSchmidtetal., author = {Gr{\"o}nke, Martin and Buschbeck, Benjamin and Schmidt, Peer and Valldor, Martin and Oswald, Steffen and Hao, Qi and Lubk, Axel and Wolf, Daniel and Steiner, Udo and B{\"u}chner, Bernd and Hampel, Silke}, title = {Chromium Trihalides CrX₃(X = Cl, Br, I): Direct Deposition of Micro- and Nanosheets on Substrates by Chemical Vapor Transport}, series = {Advanced Materials Interfaces}, volume = {6}, journal = {Advanced Materials Interfaces}, number = {24}, issn = {2196-7350}, doi = {10.1002/admi.201901410}, pages = {11}, abstract = {The experimental observation of intrinsic ferromagnetism in single layered chromium trihalides CrX₃ (X = Cl, Br, I) has gained outstanding attention recently due to their possible implementation in spintronic devices. However, the reproducible preparation of highly crystalline chromium(III) halide nanolayers without stacking faults is still an experimental challenge. As chromium trihalides consist of adjacent layers with weak interlayer coupling, the preparation of ultrathin CrX₃ nanosheets directly on substrates via vapor transport proves as an advantageous synthesis technique. It is demonstrated that vapor growth of ultrathin highly crystalline CrX₃ micro- and nanosheets succeeds directly on yttrium stabilized zirconia substrates in a one-step process via chemical vapor transport (CVT) in temperature gradients of 100 K (600°C → 500°C for CrCl₃ and 650°C → 550°C for CrBr₃ or CrI₃) without a need for subsequent delamination. Due to simulation results, optimization of synthesis conditions is realized and phase pure CrX₃ nanosheets with thicknesses ≤25 nm are obtained via short term CVT. The nanosheets morphology, crystallinity, and phase purity are analyzed by several techniques, including microscopy, diffraction, and spectroscopy. Furthermore, a potential subsequent delamination technique is demonstrated to give fast access to CrX₃ monolayers using the example of CrCl₃ .}, language = {en} } @misc{PabstChangFinzeletal., author = {Pabst, Falk and Chang, Jen-Hui and Finzel, Kati and Kohout, Miroslav and Schmidt, Peer and Ruck, Michael}, title = {The Subbromide Bi5Br4 - On the Existence of a Hidden Phase}, series = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, volume = {646}, journal = {Zeitschrift f{\"u}r Anorganische und Allgemeine Chemie}, number = {3}, doi = {10.1002/zaac.201800149}, pages = {149 -- 155}, abstract = {Black and irregularly shaped crystals of the bismuth-rich bromide Bi5Br4 were obtained as a by-product of the reaction of CsBr, Bi, and BiBr3. X-ray diffraction on a single-crystal revealed its orthorhombic structure with the space group Pmmn (no. 59) and lattice parameters a = 1800.0(2) pm, b = 1476.1(1) pm, and c = 924.5(2) pm at 296 K. The structure is composed of Bi82+ and Bi95+ polycations and bromidobismuthate(III) anions according to the structured formula Bi5Br4 = Bi20Br16 = Bi82+Bi95+[BiBr5]2-[Bi2Br11]5-. Bi5Br4 is the bismuth-richest among the bismuth subhalides containing isolated polycations. Extensive differential scanning calorimetry studies indicate that Bi5Br4 decomposes at 262 °C, i.e. one degree below the bismuth-rich eutectic at 263 °C. All attempts towards a rational synthesis yielded predominantly the neighboring phases BiBr and Bi6Br7.}, language = {en} } @misc{LangeErnstTeubneretal., author = {Lange, Felix and Ernst, Owen C. and Teubner, Thomas and Richter, Carsten and Schmidbauer, Martin and Skibitzki, Oliver and Schroeder, Thomas and Schmidt, Peer and Boeck, Torsten}, title = {In-plane growth of germanium nanowires on nanostructured Si(001)/SiO2 substrates}, series = {Nano Futures}, volume = {4}, journal = {Nano Futures}, number = {3}, issn = {2399-1984}, doi = {10.1088/2399-1984/ab82a0}, pages = {1 -- 8}, abstract = {Germanium (Ge) nanowires (NWs) were grown in-plane on nano-structured Si(001)/SiO2 substrates by molecular beam epitaxy using gold (Au) as the solvent. The site-selective NW growth was enabled by a rectangular array of gold droplets on silicon (Si) tips with an Au nuclei density below 0.25 μm-2 on the surrounding silicon oxide (SiO2). The initial growth of Ge NWs starting from Si-Au droplets with SixGe1-x nucleation from ternary alloy is discussed from a thermodynamic point of view. The in-plane NW elongation occurred within ⟨110⟩ directions on the substrate and NWs were mainly bounded by two 55◦ inclined 111 facets and a less pronounced planar (001) top facet. Fully relaxed crystal lattices of Ge NWs were observed from two-dimensional reciprocal space maps of x-ray diffraction measurements.}, language = {en} } @misc{HeinemannSchmidt, author = {Heinemann, Robert and Schmidt, Peer}, title = {Crystal Growth by Chemical Vapor Transport: Process Screening by Complementary Modeling and Experiment}, series = {Crystal Growth \& Design}, volume = {20}, journal = {Crystal Growth \& Design}, number = {9}, issn = {1528-7505}, doi = {10.1021/acs.cgd.0c00679}, pages = {5986 -- 6000}, abstract = {Despite chemical vapor transport (CVT) being a widely used method for crystal growth of inorganic substances, detailed mechanistic studies on the course of the crystallization process are rather few. In this study, an elaborated experimental screening run combined with sophisticated modeling of the respective heterogeneous equilibria is presented: Crystal growth of germanium by vapor transport with the addition of iodine has been chosen as a model system for validation of the applied method spectrum. In order to record the course and the interplay of heterogeneous equilibrium and non-equilibrium reactions in the system Ge-I, the experimental setup of high-temperature gas-balance (HTGB) is applied. Additionally, the observed evaporation processes are compared with saturation curves of corresponding volatile substances and, thus, can be assigned to individual species within the system. In this experimental screening, a phase sequence means to examine how the condensed phases undergo iodine depletion and how the gaseous phase undergoes a germanium enrichment when the temperature is increased. This phase screening combined with annealing experiments in the course of the phase sequence helps to analyze stepwise non-equilibrium products and to identify the characteristic species. Subsequently, for the evaluation of the composition of the gaseous phase, and for the deduction of the vapor transport mechanism, thermodynamic modeling by the CalPhaD method is performed. For the reference system, it is confirmed that iodine does not act as the transport agent. Instead, GeI4 is responsible for the volatilization of germanium, forming GeI2. Nevertheless, investigations clearly illustrate how GeI4 forms naturally in the phase sequence in the system Ge-I, which makes direct addition of it unnecessary. The recommended temperature range for vapor transport of germanium spans from 460 to 800 °C. Modeling shows that migration rates for germanium reaches a maximum at a mean temperature between 540 and 550 °C. Finally, vapor transport experiments were performed from 565 to 515 °C and from 690 to 590 °C. By increasing the deposition temperature, a slight decrease of the migration rate was observed, though a positive impact on the crystal's morphology was also found.}, language = {en} } @misc{JurischkaDinterEfimovaetal., author = {Jurischka, Christoph and Dinter, Franziska and Efimova, Anastasia and Weiss, Romano and Schiebel, Juliane and Schulz, Christian and Fayziev, Bekzodjon and Schierack, Peter and Fischer, Thomas and R{\"o}diger, Stefan}, title = {An explorative study of polymers for 3D printing of bioanalytical test systems}, series = {Clinical Hemorheology and Microcirculation}, volume = {75}, journal = {Clinical Hemorheology and Microcirculation}, number = {1}, issn = {1875-8622}, doi = {10.3233/CH-190713}, pages = {57 -- 84}, abstract = {Background: The 3D printing is relevant as a manufacturing technology of functional models for forensic, pharmaceutical and bioanalytical applications such as drug delivery systems, sample preparation and point-of-care tests. Objective: Melting behavior and autofluorescence of materials are decisive for optimal printing and applicability of the product which are influenced by varying unknown additives. Methods: We have produced devices for bioanalytical applications from commercially available thermoplastic polymers using a melt-layer process. We characterized them by differential scanning calorimetry, fluorescence spectroscopy and functional assays (DNA capture assay, model for cell adhesion, bacterial adhesion and biofilm formation test). Results: From 14 tested colored, transparent and black materials we found only deep black acrylonitrile-butadiene-styrene (ABS) and some black polylactic acid (PLA) useable for fluorescence-based assays, with low autofluorescence only in the short-wave range of 300-400 nm. PLA was suitable for standard bioanalytical purposes due to a glass transition temperature of approximately 60°C, resistance to common laboratory chemicals and easy print processing. For temperature-critical methods, such as hybridization reactions up to 90°C, ABS was better suited. Conclusions: Autofluorescence was not a disadvantage per se but can also be used as a reference signal in assays. The rapid development of individual protocols for sample processing and analysis required the availability of a material with consistent quality over time. For fluorescence-based assays, the use of commercial standard materials did not seem to meet this requirement.}, language = {en} } @misc{HansenWelsFroeschkeetal., author = {Hansen, Felix and Wels, Martin and Froeschke, Samuel and Popov, Alexey and Wolf, Daniel and B{\"u}chner, Bernd and Schmidt, Peer and Hampel, Silke}, title = {Thermodynamic Evaluation and Chemical Vapor Transport of Few-Layer WTe2}, series = {Crystal Growth and Design}, volume = {20}, journal = {Crystal Growth and Design}, number = {11}, issn = {1528-7505}, doi = {10.1021/acs.cgd.0c01004}, pages = {7341 -- 7349}, abstract = {Tungsten telluride WTe2 is the sole candidate of a group of two-dimensional layered transition metal dichalcogenides (TMDCs) MX2 with a thermodynamically stable 1T′-structure at room temperature. The binary system W/Te was audited with respect to a rational approach of planning and realization of a bottom-up synthesis of WTe2 nanostructures. Thus, the parameters of the synthesis via chemical vapor transports (CVT) were derived by thermodynamic simulations of the reaction pathway according to the Calphad method. Reflecting on the peritectic melting behavior at 1020 °C, the values of ΔfHm° (298 K) = -26.5 kJ·mol-1 and Sm° (298 K) = 132 J·mol-1 ·K-1 have been obtained. According to modeling, crystal growth by short time vapor transport is reasonable under the addition of bromine or TeBr4 in the temperature range between 650 and 750 °C. Experimental implementation of crystal growth of WTe2 nanosheets succeeded in a temperature gradient from 725 to 675 °C on yttria-stabilized zirconia (YSZ) (111) substrates, observing the deposition of single crystal sheets of high crystallinity with thicknesses of 15-20 nm (∼20-30 layers). The high crystallinity, pristine morphology, and overall quality of the deposited nanosheets is shown by means of atomic resolution transmission electron microscopy, selected area electron diffraction (SAED), and atomic force microscopy as well as profound double-polarized Raman spectroscopy.}, language = {en} } @misc{GaraiBonEfimovaetal., author = {Garai, Bikash and Bon, Volodymyr and Efimova, Anastasia and Gerlach, Martin and Senkovska, Irena and Kaskel, Stefan}, title = {Reversible switching between positive and negative thermal expansion in a metal-organic framework DUT-49}, series = {Journal of Materials Chemistry A}, volume = {39}, journal = {Journal of Materials Chemistry A}, number = {8}, issn = {2050-7496}, doi = {10.1039/D0TA06830F}, pages = {20420 -- 20428}, abstract = {Three-dimensional architectures constructed via coordination of organic ligands to metal ions (broadly termed metal-organic frameworks, MOFs), are highly interesting for many demanding applications such as gas adsorption, molecular separation, heterogeneous catalysis, molecular sensing, etc. Being constructed from heterogeneous components, such framework solids show characteristic features from both the individual components and framework-specific features. One such interesting physicochemical property is thermal expansion, which arises from thermal vibration from the organic linker and metal ions. Herein, we show a very unique example of thermal responsiveness for the DUT-49 framework, a MOF well-known for its distinctive negative gas adsorption (NGA) properties. In the guest-free form, the framework shows another counter-intuitive phenomenon of negative thermal expansion (NTE), i.e. the lattice size increases with decrease of temperature. However, in the solvated state, it shows both NTE and positive thermal expansion (i.e. lattice size decreases with lowering of temperature, PTE) based on a specific temperature range. When the solvent exists in the liquid form inside the MOF pore, it retains the pristine NTE nature of the bare framework. But freezing of the solvent inside the pores induces the strain, which causes a structural transformation through in-plane bending of the linker and this squeezes the framework by ∼10\% of the unit cell volume. This effect has been verified using 3 different solvents where the structural contraction occurs immediately at the freezing point of the individual solvent. Furthermore, studies on a series of DUT-49(M) frameworks with varying metals confirm the general applicability of this mechanism.}, language = {en} } @misc{KnorrIckerEfimovaetal., author = {Knorr, Monika and Icker, Maik and Efimova, Anastasia and Schmidt, Peer}, title = {Reactivity of Ionic Liquids: Studies on Thermal Decomposition Behavior of 1-Butyl-3-methylimidazolium Tetrafluoroborate}, series = {Thermochimica Acta}, volume = {Vol. 694}, journal = {Thermochimica Acta}, issn = {0040-6031}, doi = {10.1016/j.tca.2020.178786}, pages = {1 -- 11}, abstract = {The Ionic Liquid 1-butyl-3-methylimidazolium tetrafluoroborate [C4C1im]BF4 serves as a commonly solvent in inorganic material synthesis and analytics. Nevertheless, its application is frequently associated with trial and error approaches. Thereupon, detailed knowledge on the thermal behavior is the key information for understanding the reactivity of [C4C1im]BF4. 1-butyl-3-methylimidazolium tetrafluoroborate behaves as a glass in the cold, its glass transition temperature being ϑg = -83 °C. During heating with 10 K·min-1 [C4C1im]BF4 appears to be stable above 350 °C with onset temperatures ϑonset, DSC = 375 °C, ϑonset, DTG = 422 °C, and ϑonset, TG = 437 °C. Thereby, thermal decomposition occurs in a single step reaction forming 1-methyl-1H-imidazole (CH3C3H3N2 or C4H6N2), but-1-ene (C4H8), fluoromethane (CH3F) and boron trifluoride (BF3) as main species, as determined by thermogravimetry coupled with mass spectrometry and FTIR spectroscopy. To be more specific in thermal behavior, the temperature and time dependent stability is evaluated here on the basis of the kinetic model of maximum operation temperature - MOT. Clearly, thermal stability rises with application time, thus being 193 °C for one hour, while reaching only 141 °C for one day, and 114 °C for one week. The incipient decomposition (≤ 1 \%) at the calculated time dependent maximum operation temperature finally is verified by optical analysis, infrared (IR), and nuclear magnetic resonance (NMR) spectroscopy.}, language = {en} } @misc{KnorrSchmidt, author = {Knorr, Monika and Schmidt, Peer}, title = {Reactivity of ionic liquids: Reductive effect of [C4C1im]BF4 to form particles of red amorphous selenium and Bi2Se3 from oxide precursors}, series = {ChemistryOpen}, volume = {10}, journal = {ChemistryOpen}, number = {2}, issn = {2191-1363}, doi = {10.1002/open.202000264}, pages = {125 -- 140}, abstract = {Temperature-induced change in reactivity of the frequently used ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([C4C1im]BF4) is presented as a prerequisite for the rational screening of reaction courses in material synthesis. [C4C1im]BF4 becomes active with oxidic precursor compounds in reduction reaction at ϑ > 200°C, even without the addition of an external reducing agent. The reaction mechanism of forming red amorphous selenium from SeO2 is investigated as a model system and can be described similarly to the Riley oxidation. The reactive species but-1-ene, which is formed during the decomposition of [C4C1im]BF4, reacts with SeO2 and form but-3-en-2-one, water, and selenium. Elucidation of the mechanism was achieved by thermoanalytical investigations. The mono-tropic phase transition of selenium was analyzed by the differential scanning calorimetry. Beyond, the suitability of the single source oxide precursor Bi2Se3O9 for the synthesis of Bi2Se3 particles was confirmed. Identification, characterization of formed solids succeeded by using light microscopy, XRD, SEM, and EDX.}, language = {en} } @misc{KlepelUtgenanntVormelchertetal., author = {Klepel, Olaf and Utgenannt, Stephan and Vormelchert, Carolin and K{\"o}nig, Mark and Meißner, Andr{\´e} and Hansen, Felix and B{\"o}lte, Jens-Henning Ingo Holger and Sieber, Tim and Heinemann, Robert and Bron, Michael and Rokicinska, Anna and Jarczewski, Sebastian and Kustrowski, Piotr}, title = {Redox catalysts based on amorphous porous carbons}, series = {Microporous Mesoporous Materials}, volume = {323}, journal = {Microporous Mesoporous Materials}, issn = {1387-1811}, doi = {10.1016/j.micromeso.2021.111257}, pages = {12}, language = {en} } @misc{MeissnerEfimovaSchmidt, author = {Meißner, Andr{\´e} and Efimova, Anastasia and Schmidt, Peer}, title = {Impacts of TGA furnace parameters for prediction of long-term thermal stability of ionic liquids}, series = {Thermochimica Acta}, volume = {704}, journal = {Thermochimica Acta}, doi = {10.1016/j.tca.2021.178917}, pages = {178917-1 -- 178917-7}, abstract = {The concept of maximum operation temperature is established for the prediction of the time dependent thermal stability of ionic liquids based on kinetic evaluation of thermogravimetric analysis. The influence of the furnace control parameters on the maximum operation temperature (MOT) is shown using the example of 1-methyl-3-propylimidazolium iodide ([C3C1im]I) with respect to three different parameter sets of a programmed proportional integral derivative (PID) controller of the TGA. Kinetics of thermal decomposition of [C3C1im]I have been investigated with the implementation of an improved kinetic model. The activation energy obtained using the Kissinger-Akahira-Sunose equation showed variations apparently due to the decomposition degree. The model compound is decomposed by a one-step kinetics, which results from pseudo zero order relationship of the activation energy to the conversion rate. The activation energy, pre-exponential factor, and the activation energy are strongly dependent on the parameters of TGA furnace controller.}, language = {en} }