TY - JOUR A1 - Jelicic, Aleksandra A1 - Yasin, Muttaqin A1 - Beuermann, Sabine T1 - Toward the description and prediction of solvent induced variations in Methacrylate Propagation Rate Coefficients on the basis of Solvatochromic Parameters JF - Macromolecular reaction engineering N2 - Benzyl methacrylate (BzMA) propagation rate coefficients, k(p), were determined in ionic liquids and common organic solvents via pulsed-laser polymerizations with subsequent polymer analysis by size-exclusion chromatography (PLP-SEC). The aim of the work is to gain a deeper understanding of the solvent influence on k(p) and to develop a general correlation between solvent-induced variations in k(p) and solvent properties. Applying a linear solvation energy relationship (LSER), which correlates k(p) to solvent solvatochromic parameters, suggests that dipolarity/polarizability determines the solvent influence on k(p). To compare the solvent influence on BzMA k(p) with data for methyl methacrylate, hydroxypropyl methacrylate, and 2-ethoxyethyl methacrylate normalized k(p) data were treated by a single LSER, providing a universal treatment of the solvent influence on the propagation kinetics of the four monomers. Further, the predictive capabilities of this universal correlation were tested with additional monomers from the methacrylate family. KW - ionic liquid KW - kinetics (polym.) KW - radical polymerization KW - solvent influence Y1 - 2011 U6 - https://doi.org/10.1002/mren.201000058 SN - 1862-832X VL - 5 IS - 5-6 SP - 232 EP - 242 PB - Wiley-Blackwell CY - Malden ER - TY - JOUR A1 - Winter, Alette A1 - Zabel, Andre A1 - Strauch, Peter T1 - Tetrachloridocuprates(II)-Synthesis and Electron Paramagnetic Resonance (EPR) Spectroscopy JF - International journal of molecular sciences N2 - Ionic liquids (ILs) on the basis of metal containing anions and/or cations are of interest for a variety of technical applications e.g., synthesis of particles, magnetic or thermochromic materials. We present the synthesis and the results of electron paramagnetic resonance (EPR) spectroscopic analyses of a series of some new potential ionic liquids based on tetrachloridocuprates(II), [CuCl4](2-), with different sterically demanding cations: hexadecyltrimethylammonium 1, tetradecyltrimethylammonium 2, tetrabutylammonium 3 and benzyltriethylammonium 4. The cations in the new compounds were used to achieve a reasonable separation of the paramagnetic Cu(II) ions for EPR spectroscopy. The EPR hyperfine structure was not resolved. This is due to the exchange broadening, resulting from still incomplete separation of the paramagnetic Cu(II) centers. Nevertheless, the principal values of the electron Zeemann tensor (g parallel to and g perpendicular to) of the complexes could be determined. Even though the solid substances show slightly different colors, the UV/Vis spectra are nearly identical, indicating structural changes of the tetrachloridocuprate moieties between solid state and solution. The complexes have a promising potential e.g., as high temperature ionic liquids, as precursors for the formation of copper chloride particles or as catalytic paramagnetic ionic liquids. KW - tetrachloridocuprate(II) KW - electron paramagnetic resonance KW - copper(II) KW - ionic liquid Y1 - 2012 U6 - https://doi.org/10.3390/ijms13021612 SN - 1661-6596 VL - 13 IS - 2 SP - 1612 EP - 1619 PB - MDPI CY - Basel ER - TY - THES A1 - Mondal, Suvendu Sekhar T1 - Design of isostructural metal-imidazolate frameworks : application for gas storage T1 - Synthese isostruktureller Metall-Imidazolat Frameworks : Anwendung für Gasspeicherung N2 - The sharply rising level of atmospheric carbon dioxide resulting from anthropogenic emissions is one of the greatest environmental concerns facing our civilization today. Metal-organic frameworks (MOFs) are a new class of materials that constructed by metal-containing nodes bonded to organic bridging ligands. MOFs could serve as an ideal platform for the development of next generation CO2 capture materials owing to their large capacity for the adsorption of gases and their structural and chemical tunability. The ability to rationally select the framework components is expected to allow the affinity of the internal pore surface toward CO2 to be precisely controlled, facilitating materials properties that are optimized for the specific type of CO2 capture to be performed (post-combustion capture, precombustion capture, or oxy-fuel combustion) and potentially even for the specific power plant in which the capture system is to be installed. For this reason, significant effort has been made in recent years in improving the gas separation performance of MOFs and some studies evaluating the prospects of deploying these materials in real-world CO2 capture systems have begun to emerge. We have developed six new MOFs, denoted as IFPs (IFP-5, -6, -7, -8, -9, -10, IFP = Imidazolate Framework Potsdam) and two hydrogen-bonded molecular building block (MBB, named as 1 and 2 for Zn and Co based, respectively) have been synthesized, characterized and applied for gas storage. The structure of IFP possesses 1D hexagonal channels. Metal centre and the substituent groups of C2 position of the linker protrude into the open channels and determine their accessible diameter. Interestingly, the channel diameters (range : 0.3 to 5.2 Å) for IFP structures are tuned by the metal centre (Zn, Co and Cd) and substituent of C2 position of the imidazolate linker. Moreover hydrogen bonded MBB of 1 and 2 is formed an in situ functionalization of a ligand under solvothermal condition. Two different types of channels are observed for 1 and 2. Materials contain solvent accessible void space. Solvent could be easily removed by under high vacuum. The porous framework has maintained the crystalline integrity even without solvent molecules. N2, H2, CO2 and CH4 gas sorption isotherms were performed. Gas uptake capacities are comparable with other frameworks. Gas uptake capacity is reduced when the channel diameter is narrow. For example, the channel diameter of IFP-5 (channel diameter: 3.8 Å) is slightly lower than that of IFP-1 (channel diameter: 4.2 Å); hence, the gas uptake capacity and Brunauer-Emmett-Teller (BET) surface area are slightly lower than IFP-1. The selectivity does not depend only on the size of the gas components (kinetic diameter: CO2 3.3 Å, N2 3.6 Å and CH4 3.8 ) but also on the polarizability of the surface and of the gas components. IFP-5 and-6 have the potential applications for the separation of CO2 and CH4 from N2-containing gas mixtures and CO2 and CH4 containing gas mixtures. Gas sorption isotherms of IFP-7, -8, -9, -10 exhibited hysteretic behavior due to flexible alkoxy (e.g., methoxy and ethoxy) substituents. Such phenomenon is a kind of gate effects which is rarely observed in microporous MOFs. IFP-7 (Zn-centred) has a flexible methoxy substituent. This is the first example where a flexible methoxy substituent shows the gate opening behavior in a MOF. Presence of methoxy functional group at the hexagonal channels, IFP-7 acted as molecular gate for N2 gas. Due to polar methoxy group and channel walls, wide hysteretic isotherm was observed during gas uptake. The N2 The estimated BET surface area for 1 is 471 m2 g-1 and the Langmuir surface area is 570 m2 g-1. However, such surface area is slightly higher than azolate-based hydrogen-bonded supramolecular assemblies and also comparable and higher than some hydrogen-bonded porous organic molecules. N2 - Metallorganische Gerüstverbindungen (MOFs) sind eine neue Klasse von porösen Koordinationspolymeren, die aus Metall-Knoten und verbrückenden Liganden bestehen. MOFs können Gasgemische trennen und Gase speichern. Aufgrund ihres modularen Aufbaus können die MOF-Eigenschaften systematisch variiert werden. Ein wichtiges Ziel für das Design von MOFs ist die Synthese von Materialien, die eine hohe selektive Aufnahmefähigkeit und -kapazität für Kohlenstoffdioxid besitzen. Im Rahmen der Arbeit ist es gelungen sechs neue MOFs (IFP-5, -6, -7, -8, -9 und -10) zu synthetisieren. Diese MOFs tragen die Kurzbezeichnung IFP. IFP steht als Abkürzung für Imidazolat-Framework-Potsdam (Imidazolat-basierte Gerüstverbindung Potsdam). In diesen IFPs wurde der Metallknoten (Zink, Cobalt, Cadmium) und der Brückenligand, ein 2-substituiertes Imidazolat-amid-imidat, in der Position variiert, um gute und selektive Sorptionseigenschaften für Kohlenstoffdioxid zu erzielen. Von den synthetisierten Verbindungen hat das IFP-5 die besten Sorptionseigenschaften für Kohlenstoffdioxid. Es konnte weiter gezeigt werden, dass sich die IFP-Struktur bei der Wahl von geeigneten Substituenten 2, wie z.B. Methoxy und Ethoxy auch für das Design von gate-opening (Tür-öffnenden) Effekten eignet. Diese Effekte können wiederum genutzt werden, um selektiv Gasmischungen zu trennen. Wenn man das 4,5-Dicyano-2-methoxy-imidazol in Gegenwart von Zink- und Cobalt-Salzen unter solvothermalen Bedingungen zur Reaktion bringt, erhält man beispiellose supramolekulare Wasserstoffbrückenbindungen zu einem dreidimensionalen Netzwerk, die mit Kanälen verknüpft sind. Diese Kanäle können von Lösungsmittelmolekülen (Wasser und Dimethylformamid) befreit werden und Gase aufnehmen. Insgesamt besteht nun die neue MOF-Klasse der Imidazolat-basierten IFPs aus Vertretern. Das Potential der 2-substituierten 4,5-Dicyanoimidazole ist nicht nur auf die Bildung von porösen Koordinationspolymeren beschränkt, sondern kann auch für die Synthese von bisher unbekannten supramolekularen Strukturen genutzt werden. KW - Metal-organic framework KW - Gas Sorption KW - Cobalt KW - Zinc KW - Ionic Liquid KW - metal-organic framework KW - gas sorption KW - cobalt KW - zinc KW - ionic liquid Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-69692 ER - TY - GEN A1 - Winter, Alette A1 - Thiel, Kerstin A1 - Zabel, André A1 - Klamroth, Tillmann A1 - Pöppl, Andreas A1 - Kelling, Alexandra A1 - Schilde, Uwe A1 - Taubert, Andreas A1 - Strauch, Peter T1 - Tetrahalidocuprates(II) – structure and EPR spectroscopy BT - Part 2: tetrachloridocuprates(II) N2 - We present and discuss the results of crystallographic and electron paramagnetic resonance (EPR) spectroscopic analyses of five tetrachloridocuprate(II) complexes to supply a useful tool for the structural characterisation of the [CuCl4]2− moiety in the liquid state, for example in ionic liquids, or in solution. Bis(benzyltriethylammonium)-, bis(trimethylphenylammonium)-, bis(ethyltriphenylphosphonium)-, bis(benzyltriphenylphosphonium)-, and bis(tetraphenylarsonium)tetrachloridocuprate(II) were synthesised and characterised by elemental, IR, EPR and X-ray analyses. The results of the crystallographic analyses show distorted tetrahedral coordination geometry of all [CuCl4]2− anions in the five complexes and prove that all investigated complexes are stabilised by hydrogen bonds of different intensities. Despite the use of sterically demanding ammonium, phosphonium and arsonium cations to obtain the separation of the paramagnetic Cu(II) centres for EPR spectroscopy no hyperfine structure was observed in the EPR spectra but the principal values of the electron Zeeman tensor, g∥ and g⊥, could be determined. With these EPR data and the crystallographic parameters we were able to carry out a correlation study to anticipate the structural situation of tetrachloridocuprates in different physical states. This correlation is in good agreement with DFT calculations. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 240 KW - electron-spin resonance KW - liquid-crystal precursors KW - copper(II) halide salts KW - ionic liquid KW - square planar KW - tetrachlorocuprate(II) salts KW - molecular-structure KW - magnetic-properties KW - paramagnetic-resonance KW - temperature phase Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-95012 SP - 1019 EP - 1030 ER - TY - JOUR A1 - Salama, Ahmed A1 - Neumann, Mike A1 - Günter, Christina A1 - Taubert, Andreas T1 - Ionic liquid-assisted formation of cellulose/calcium phosphate hybrid materials JF - Beilstein journal of nanotechnology N2 - Cellulose/calcium phosphate hybrid materials were synthesized via an ionic liquid-assisted route. Scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, infrared spectroscopy, and thermogravimetric analysis/differential thermal analysis show that, depending on the reaction conditions, cellulose/hydroxyapatite, cellulose/ chlorapatite, or cellulose/monetite composites form. Preliminary studies with MC3T3-E1 pre-osteoblasts show that the cells proliferate on the hybrid materials suggesting that the ionic liquid-based process yields materials that are potentially useful as scaffolds for regenerative therapies. KW - biomineralization KW - calcium phosphate KW - carbohydrates KW - cellulose KW - hybrid materials KW - ionic liquid Y1 - 2014 U6 - https://doi.org/10.3762/bjnano.5.167 SN - 2190-4286 VL - 5 SP - 1553 EP - 1568 PB - Beilstein-Institut zur Förderung der Chemischen Wissenschaften CY - Frankfurt, Main ER - TY - GEN A1 - Tao, Lumi A1 - Liu, Yuchuan A1 - Wu, Dan A1 - Wei, Qiao-Hua A1 - Taubert, Andreas A1 - Xie, Zailai T1 - Luminescent Ionogels with Excellent Transparency, High Mechanical Strength, and High Conductivity T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - The paper describes a new kind of ionogel with both good mechanical strength and high conductivity synthesized by confining the ionic liquid (IL) 1-butyl-3-methylimidazolium bis(trifluoromethane sulfonyl)imide ([Bmim][NTf₂]) within an organic–inorganic hybrid host. The organic–inorganic host network was synthesized by the reaction of methyltrimethoxysilane (MTMS), tetraethoxysilane (TEOS), and methyl methacrylate (MMA) in the presence of a coupling agent, offering the good mechanical strength and rapid shape recovery of the final products. The silane coupling agent 3-methacryloxypropyltrimethoxysilane (KH-570) plays an important role in improving the mechanical strength of the inorganic–organic hybrid, because it covalently connected the organic component MMA and the inorganic component SiO₂. Both the thermal stability and mechanical strength of the ionogel significantly increased by the addition of IL. The immobilization of [Bmim][NTf₂] within the ionogel provided the final ionogel with an ionic conductivity as high as ca. 0.04 S cm⁻¹ at 50 °C. Moreover, the hybrid ionogel can be modified with organosilica-modified carbon dots within the network to yield a transparent and flexible ionogel with strong excitation-dependent emission between 400 and 800 nm. The approach is, therefore, a blueprint for the construction of next-generation multifunctional ionogels. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1058 KW - ionic liquid KW - ionogel KW - carbon dots KW - organic–inorganic hybrid KW - luminescence KW - mechanical strength Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-487334 SN - 1866-8372 IS - 1058 ER - TY - JOUR A1 - Tao, Lumi A1 - Liu, Yuchuan A1 - Wu, Dan A1 - Wei, Qiao-Hua A1 - Taubert, Andreas A1 - Xie, Zailai T1 - Luminescent Ionogels with Excellent Transparency, High Mechanical Strength, and High Conductivity JF - Nanomaterials N2 - The paper describes a new kind of ionogel with both good mechanical strength and high conductivity synthesized by confining the ionic liquid (IL) 1-butyl-3-methylimidazolium bis(trifluoromethane sulfonyl)imide ([Bmim][NTf₂]) within an organic–inorganic hybrid host. The organic–inorganic host network was synthesized by the reaction of methyltrimethoxysilane (MTMS), tetraethoxysilane (TEOS), and methyl methacrylate (MMA) in the presence of a coupling agent, offering the good mechanical strength and rapid shape recovery of the final products. The silane coupling agent 3-methacryloxypropyltrimethoxysilane (KH-570) plays an important role in improving the mechanical strength of the inorganic–organic hybrid, because it covalently connected the organic component MMA and the inorganic component SiO₂. Both the thermal stability and mechanical strength of the ionogel significantly increased by the addition of IL. The immobilization of [Bmim][NTf₂] within the ionogel provided the final ionogel with an ionic conductivity as high as ca. 0.04 S cm⁻¹ at 50 °C. Moreover, the hybrid ionogel can be modified with organosilica-modified carbon dots within the network to yield a transparent and flexible ionogel with strong excitation-dependent emission between 400 and 800 nm. The approach is, therefore, a blueprint for the construction of next-generation multifunctional ionogels. KW - ionic liquid KW - ionogel KW - carbon dots KW - organic–inorganic hybrid KW - luminescence KW - mechanical strength Y1 - 2020 U6 - https://doi.org/10.3390/nano10122521 SN - 2079-4991 VL - 10 IS - 12 PB - MDPI CY - Basel ER - TY - JOUR A1 - Sperlich, Eric A1 - Köckerling, Martin T1 - Cluster salts [Nb6Cl12(HIm)(6)]A(n) (with HIm=1H-imidazole and A=Mineral Acid Anion, n=1 or 2) made in and with Bronsted-basic ionic liquids and liquid mixtures JF - ChemistryOpen N2 - Four new hexanuclear niobium cluster compounds of the general formula [Nb6Cl12(HIm)(6)](A)(n) . x(solvent molecule) (HIm=1H-imidazole, A=mineral acid anion, Cl- (n=2) (1), (SO4)(2-) (n=1) (2), (CrO4)(2-) (n=1) (3), and (HAsO4)(2-) (n=1) (4)) were prepared. Their synthesis can be done in basic ionic liquids, which form on the addition of a mineral acid, which also delivers the counter anion for the final cluster compound, to an excess of the 1H-imidazole. Some addition of an auxiliary solvent, like methanol, improves the speed of crystallisation. The cluster unit comprises a hexanuclear Nb-6 unit of octahedral shape with the edges bridged by Cl atoms and the exo sites being occupied by N-bonded 1H-imidazole ligands. The cluster cation carries sixteen cluster-based electrons. Between the NH groups of the ligands of the cluster unit, the anions and the co-crystallised water (1), or 1H-imidazole and methanol molecules (2, 3, and 4) a network of hydrogen bonds exists. KW - cluster KW - ionic liquid KW - structure elucidation KW - heterocyclic ligand KW - Niobium Y1 - 2021 U6 - https://doi.org/10.1002/open.202000266 SN - 2191-1363 VL - 10 IS - 2 SP - 248 EP - 254 PB - Wiley-VCH CY - Weinheim ER -