TY - JOUR A1 - Mondal, Suvendu Sekhar A1 - Behrens, Karsten A1 - Kelling, Alexandra A1 - Nabein, Hans-Peter A1 - Schilde, Uwe A1 - Holdt, Hans-Jürgen T1 - Two Cd-II/Co-II-Imidazolate Coordination Polymers: Syntheses, Crystal Structures, Stabilities, and Luminescent/Magnetic Properties JF - Zeitschrift für anorganische und allgemeine Chemie N2 - Cadmium(II) based 2D coordination polymer [Cd(L1)(2)(DMF)(2)] (1) (L1 = 4,5-dicyano-2-methylimidazolate, DMF = N,N'-dimethylformamide) and 2D cobalt(II)-imidazolate framework [Co(L3)(4)] (2) (L3 = 4,5-diamide-2-ethoxyimidazolate) were synthesized under solvothermal reaction conditions. The materials were characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, powder X-ray diffraction measurement (PXRD) and single-crystal X-ray diffraction. Compound 1 has hexacoordinate Cd-II ions and forms a zigzag chain-like coordination polymer structure, whereas compound 2 exhibits a 2D square grid type structure. The thermal stability analysis reveals that 2 showed an exceptional thermal stability up to 360 degrees C. Also, 2 maintained its fully crystalline integrity in boiling water as confirmed by PXRD. The solid state luminescent property of 1 was not observed at room temperature. Compound 2 showed an independent high spin central Co-II atom. KW - Cobalt KW - Cadmium KW - Coordination polymers KW - Crystal structures KW - Imidazole Y1 - 2015 U6 - https://doi.org/10.1002/zaac.201500526 SN - 0044-2313 SN - 1521-3749 VL - 641 IS - 11 SP - 1991 EP - 1997 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Hovestadt, Maximilian A1 - Bendt, Stephan A1 - Mondal, Suvendu Sekhar A1 - Behrens, Karsten A1 - Reif, Florian A1 - Dopken, Merle A1 - Holdt, Hans-Jürgen A1 - Keil, Frerich J. A1 - Hartmann, Martin T1 - Experimental and Theoretical Analysis of the Influence of Different Linker Molecules in Imidazolate Frameworks Potsdam (IFP-n) on the Separation of Olefin-Paraffin Mixtures JF - Langmuir N2 - Four metal organic frameworks with similar topology but different chemical environment inside the pore structure, namely, IFP-1, IFP-3, IFP-5, and IFP-7, have been investigated with respect to the separation potential for olefin paraffin mixtures as well as the influence of the different linkers on adsorption properties using experiments and Monte Carlo simulations. All IFP structures show a higher adsorption of ethane compared to ethene with the exception of IFP-7 which shows no selectivity in breakthrough experiments. For propane/propane separation, all adsorbents show a higher adsorption for the olefin. The experimental results agree quite well with the simulated values except for the IFP-7, which is presumably due to the flexibility of the structure. Moreover, the experimental and simulated isotherms were confirmed with breakthrough experiments that render IFP-1, IFP-3, and IFP-5 as suitable for the purification of ethene from ethane. Y1 - 2017 U6 - https://doi.org/10.1021/acs.langmuir.7b02016 SN - 0743-7463 VL - 33 SP - 11170 EP - 11179 PB - American Chemical Society CY - Washington ER - TY - THES A1 - Behrens, Karsten T1 - Mikrowellen-assistierte Synthese von IFPs und Darstellung von lumineszierenden Lanthanid-IFP-Materialien Y1 - 2017 ER - TY - GEN A1 - Behrens, Karsten A1 - Balischewski, Christian A1 - Sperlich, Eric A1 - Menski, Antonia Isabell A1 - Balderas-Valadez, Ruth Fabiola A1 - Pacholski, Claudia A1 - Günter, Christina A1 - Lubahn, Susanne A1 - Kelling, Alexandra A1 - Taubert, Andreas T1 - Mixed chloridometallate(ii) ionic liquids with tunable color and optical response for potential ammonia sensors T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Eight d-metal-containing N-butylpyridinium ionic liquids (ILs) with the nominal composition (C4Py)2[Ni0.5M0.5Cl4] or (C4Py)2[Zn0.5M0.5Cl4] (M = Cu, Co, Mn, Ni, Zn; C4Py = N-butylpyridinium) were synthesized, characterized, and investigated for their optical properties. Single crystal and powder X-ray analysis shows that the compounds are isostructural to existing examples based on other d-metal ions. Inductively coupled plasma optical emission spectroscopy measurements confirm that the metal/metal ratio is around 50 : 50. UV-Vis spectroscopy shows that the optical absorption can be tuned by selection of the constituent metals. Moreover, the compounds can act as an optical sensor for the detection of gases such as ammonia as demonstrated via a simple prototype setup. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1316 Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-587512 SN - 1866-8372 IS - 1316 SP - 35072 EP - 35082 ER - TY - JOUR A1 - Balischewski, Christian A1 - Behrens, Karsten A1 - Zehbe, Kerstin A1 - Günter, Christina A1 - Mies, Stefan A1 - Sperlich, Eric A1 - Kelling, Alexandra A1 - Taubert, Andreas T1 - Ionic liquids with more than one metal BT - optical and rlectrochemical properties versus d-block metal vombinations JF - Chemistry - a European journal N2 - Thirteen N-butylpyridinium salts, including three monometallic [C4Py](2)[MCl4], nine bimetallic [C4Py](2)[(M1-xMxCl4)-M-a-Cl-b] and one trimetallic compound [C4Py](2)[(M1-y-zMyMz (c) Cl4)-M-a-M-b] (M=Co, Cu, Mn; x=0.25, 0.50 or 0.75 and y=z=0.33), were synthesized and their structure and thermal and electrochemical properties were studied. All compounds are ionic liquids (ILs) with melting points between 69 and 93 degrees C. X-ray diffraction proves that all ILs are isostructural. The conductivity at room temperature is between 10(-4) and 10(-8) S cm(-1). Some Cu-based ILs reach conductivities of 10(-2) S cm(-1), which is, however, probably due to IL dec. This correlates with the optical bandgap measurements indicating the formation of large bandgap semiconductors. At elevated temperatures approaching the melting points, the conductivities reach up to 1.47x10(-1) S cm(-1) at 70 degrees C. The electrochemical stability windows of the ILs are between 2.5 and 3.0 V. KW - bandgap KW - electrochemistry KW - ionic liquids KW - metal-containing ionic KW - liquids KW - tetrahalido metallates Y1 - 2020 U6 - https://doi.org/10.1002/chem.202003097 SN - 0947-6539 SN - 1521-3765 VL - 26 IS - 72 SP - 17504 EP - 17513 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Behrens, Karsten A1 - Balischewski, Christian A1 - Sperlich, Eric A1 - Menski, Antonia Isabell A1 - Balderas-Valadez, Ruth Fabiola A1 - Pacholski, Claudia A1 - Günter, Christina A1 - Lubahn, Susanne A1 - Kelling, Alexandra A1 - Taubert, Andreas T1 - Mixed chloridometallate(ii) ionic liquids with tunable color and optical response for potential ammonia sensors JF - RSC Advances N2 - Eight d-metal-containing N-butylpyridinium ionic liquids (ILs) with the nominal composition (C4Py)2[Ni0.5M0.5Cl4] or (C4Py)2[Zn0.5M0.5Cl4] (M = Cu, Co, Mn, Ni, Zn; C4Py = N-butylpyridinium) were synthesized, characterized, and investigated for their optical properties. Single crystal and powder X-ray analysis shows that the compounds are isostructural to existing examples based on other d-metal ions. Inductively coupled plasma optical emission spectroscopy measurements confirm that the metal/metal ratio is around 50 : 50. UV-Vis spectroscopy shows that the optical absorption can be tuned by selection of the constituent metals. Moreover, the compounds can act as an optical sensor for the detection of gases such as ammonia as demonstrated via a simple prototype setup. Y1 - 2022 U6 - https://doi.org/10.1039/d2ra05581c SN - 2046-2069 VL - 12 SP - 35072 EP - 35082 PB - RSC CY - London ER - TY - JOUR A1 - Balischewski, Christian A1 - Bhattacharyya, Biswajit A1 - Sperlich, Eric A1 - Günter, Christina A1 - Beqiraj, Alkit A1 - Klamroth, Tillmann A1 - Behrens, Karsten A1 - Mies, Stefan A1 - Kelling, Alexandra A1 - Lubahn, Susanne A1 - Holtzheimer, Lea A1 - Nitschke, Anne A1 - Taubert, Andreas T1 - Tetrahalidometallate(II) ionic liquids with more than one metal BT - the effect of bromide versus chloride JF - Chemistry - a European journal N2 - Fifteen N-butylpyridinium salts - five monometallic [C4Py](2)[MBr4] and ten bimetallic [C4Py](2)[(M0.5M0.5Br4)-M-a-Br-b] (M=Co, Cu, Mn, Ni, Zn) - were synthesized, and their structures and thermal and electrochemical properties were studied. All the compounds are ionic liquids (ILs) with melting points between 64 and 101 degrees C. Powder and single-crystal X-ray diffraction show that all ILs are isostructural. The electrochemical stability windows of the ILs are between 2 and 3 V. The conductivities at room temperature are between 10(-5) and 10(-6) S cm(-1). At elevated temperatures, the conductivities reach up to 10(-4) S cm(-1) at 70 degrees C. The structures and properties of the current bromide-based ILs were also compared with those of previous examples using chloride ligands, which illustrated differences and similarities between the two groups of ILs. KW - electrochemistry KW - ionic liquids KW - metal-containing ionic liquids; KW - N-butylpyridinium bromide KW - tetrahalidometallates Y1 - 2022 U6 - https://doi.org/10.1002/chem.202201068 SN - 1521-3765 VL - 28 IS - 64 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Balischewski, Christian A1 - Choi, Hyung-Seok A1 - Behrens, Karsten A1 - Beqiraj, Alkit A1 - Körzdörfer, Thomas A1 - Gessner, Andre A1 - Wedel, Armin A1 - Taubert, Andreas T1 - Metal sulfide nanoparticle synthesis with ionic liquids state of the art and future perspectives JF - ChemistryOpen N2 - Metal sulfides are among the most promising materials for a wide variety of technologically relevant applications ranging from energy to environment and beyond. Incidentally, ionic liquids (ILs) have been among the top research subjects for the same applications and also for inorganic materials synthesis. As a result, the exploitation of the peculiar properties of ILs for metal sulfide synthesis could provide attractive new avenues for the generation of new, highly specific metal sulfides for numerous applications. This article therefore describes current developments in metal sulfide nano-particle synthesis as exemplified by a number of highlight examples. Moreover, the article demonstrates how ILs have been used in metal sulfide synthesis and discusses the benefits of using ILs over more traditional approaches. Finally, the article demonstrates some technological challenges and how ILs could be used to further advance the production and specific property engineering of metal sulfide nanomaterials, again based on a number of selected examples. KW - Ionic liquids KW - ionic liquid crystals KW - ionic liquid precursors KW - metal KW - sulfides KW - catalysis KW - electrochemistry KW - energy materials KW - LED KW - solar KW - cells Y1 - 2021 U6 - https://doi.org/10.1002/open.202000357 SN - 2191-1363 VL - 10 IS - 2 SP - 272 EP - 295 PB - Wiley-VCH CY - Weinheim ER - TY - GEN A1 - Taubert, Andreas A1 - Balischewski, Christian A1 - Hentrich, Doreen A1 - Elschner, Thomas A1 - Eidner, Sascha A1 - Günter, Christina A1 - Behrens, Karsten A1 - Heinze, Thomas T1 - Water-soluble cellulose derivatives are sustainable additives for biomimetic calcium phosphate mineralization N2 - The effect of cellulose-based polyelectrolytes on biomimetic calcium phosphate mineralization is described. Three cellulose derivatives, a polyanion, a polycation, and a polyzwitterion were used as additives. Scanning electron microscopy, X-ray diffraction, IR and Raman spectroscopy show that, depending on the composition of the starting solution, hydroxyapatite or brushite precipitates form. Infrared and Raman spectroscopy also show that significant amounts of nitrate ions are incorporated in the precipitates. Energy dispersive X-ray spectroscopy shows that the Ca/P ratio varies throughout the samples and resembles that of other bioinspired calcium phosphate hybrid materials. Elemental analysis shows that the carbon (i.e., polymer) contents reach 10% in some samples, clearly illustrating the formation of a true hybrid material. Overall, the data indicate that a higher polymer concentration in the reaction mixture favors the formation of polymer-enriched materials, while lower polymer concentrations or high precursor concentrations favor the formation of products that are closely related to the control samples precipitated in the absence of polymer. The results thus highlight the potential of (water-soluble) cellulose derivatives for the synthesis and design of bioinspired and bio-based hybrid materials. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 354 KW - cellulose KW - polyamine KW - polyammonium salt KW - polycarboxylate KW - polyzwitterion KW - calcium phosphate KW - biomineralization KW - brushite KW - hydroyxapatite KW - biomaterial Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-400453 ER - TY - JOUR A1 - Taubert, Andreas A1 - Balischewski, Christian A1 - Hentrich, Doreen A1 - Elschner, Thomas A1 - Eidner, Sascha A1 - Günter, Christina A1 - Behrens, Karsten A1 - Heinze, Thomas T1 - Water-Soluble Cellulose Derivatives Are Sustainable Additives for Biomimetic Calcium Phosphate Mineralization JF - Inorganics : open access journal N2 - The effect of cellulose-based polyelectrolytes on biomimetic calcium phosphate mineralization is described. Three cellulose derivatives, a polyanion, a polycation, and a polyzwitterion were used as additives. Scanning electron microscopy, X-ray diffraction, IR and Raman spectroscopy show that, depending on the composition of the starting solution, hydroxyapatite or brushite precipitates form. Infrared and Raman spectroscopy also show that significant amounts of nitrate ions are incorporated in the precipitates. Energy dispersive X-ray spectroscopy shows that the Ca/P ratio varies throughout the samples and resembles that of other bioinspired calcium phosphate hybrid materials. Elemental analysis shows that the carbon (i.e., polymer) contents reach 10% in some samples, clearly illustrating the formation of a true hybrid material. Overall, the data indicate that a higher polymer concentration in the reaction mixture favors the formation of polymer-enriched materials, while lower polymer concentrations or high precursor concentrations favor the formation of products that are closely related to the control samples precipitated in the absence of polymer. The results thus highlight the potential of (water-soluble) cellulose derivatives for the synthesis and design of bioinspired and bio-based hybrid materials. KW - cellulose KW - polyamine KW - polyammonium salt KW - polycarboxylate KW - polyzwitterion KW - calcium phosphate KW - biomineralization KW - brushite KW - hydroyxapatite KW - biomaterial Y1 - 2016 U6 - https://doi.org/10.3390/inorganics4040033 SN - 2304-6740 VL - 4 PB - MDPI CY - Basel ER - TY - JOUR A1 - Debatin, Franziska A1 - Behrens, Karsten A1 - Weber, Jens A1 - Baburin, Igor A. A1 - Thomas, Arne A1 - Schmidt, Johannes A1 - Senkovska, Irena A1 - Kaskel, Stefan A1 - Kelling, Alexandra A1 - Hedin, Niklas A1 - Bacsik, Zoltan A1 - Leoni, Stefano A1 - Seifert, Gotthard A1 - Jäger, Christian A1 - Günter, Christina A1 - Schilde, Uwe A1 - Friedrich, Alwin A1 - Holdt, Hans-Jürgen T1 - An isoreticular family of microporous metal-organic frameworks based on zinc and 2-substituted imidazolate-4-amide-5-imidate Syntheses, structures and properties JF - Chemistry - a European journal N2 - We report on a new series of isoreticular frameworks based on zinc and 2-substituted imidazolate-4-amide-5-imidate (IFP-14, IFP=imidazolate framework Potsdam) that form one-dimensional, microporous hexagonal channels. Varying R in the 2-substitued linker (R=Me (IFP-1), Cl (IFP-2), Br (IFP-3), Et (IFP-4)) allowed the channel diameter (4.01.7 angstrom), the polarisability and functionality of the channel walls to be tuned. Frameworks IFP-2, IFP-3 and IFP-4 are isostructural to previously reported IFP-1. The structures of IFP-2 and IFP-3 were solved by X-ray crystallographic analyses. The structure of IFP-4 was determined by a combination of PXRD and structure modelling and was confirmed by IR spectroscopy and 1H MAS and 13C CP-MAS NMR spectroscopy. All IFPs showed high thermal stability (345400?degrees C); IFP-1 and IFP-4 were stable in boiling water for 7 d. A detailed porosity analysis was performed on the basis of adsorption measurements by using various gases. The potential of the materials to undergo specific interactions with CO2 was investigated by measuring the isosteric heats of adsorption. The capacity to adsorb CH4 (at 298 K), CO2 (at 298 K) and H2 (at 77 K) at high pressure were also investigated. In situ IR spectroscopy showed that CO2 is physisorbed on IFP-14 under dry conditions and that both CO2 and H2O are physisorbed on IFP-1 under moist conditions. KW - adsorption KW - metal- organic frameworks KW - microporous materials KW - N KW - O ligands KW - zinc Y1 - 2012 U6 - https://doi.org/10.1002/chem.201200889 SN - 0947-6539 VL - 18 IS - 37 SP - 11630 EP - 11640 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Behrens, Karsten A1 - Mondal, Suvendu Selchar A1 - Nöske, Robert A1 - Baburin, Igor A. A1 - Leoni, Stefano A1 - Günter, Christina A1 - Weber, Jens A1 - Holdt, Hans-Jürgen T1 - Microwave-Assisted Synthesis of Defects Metal-Imidazolate-Amide-Imidate Frameworks and Improved CO2 Capture JF - Inorganic chemistry N2 - In this work, we report three isostructural 3D frameworks, named IFP-11 (R = Cl), IFP-12 (R = Br), and IFP-13 (R = Et) (IFP = Imidazolate Framework Potsdam) based on a cobalt(II) center and the chelating linker 2-substituted imidazolate-4-amide-5-imidate. These chelating ligands were generated in situ by partial hydrolysis of 2-substituted 4,5-dicyanoimidazoles under microwave (MW)-assisted conditions in DMF. Structure determination of these IFPs was investigated by IR spectroscopy and a combination of powder X-ray diffraction (PXRD) with structure modeling. The structural models were initially built up from the single-crystal X-ray structure determination of IFP-5 (a cobalt center and 2-methylimidazolate-4-amide-5-imidate linker based framework) and were optimized by using density functional theory calculations. Substitution on position 2 of the linker (R = Cl, Br, and Et) in the isostructural IFP-11, -12, and -13 allowed variation of the potential pore window in 1D hexagonal channels (3.8 to 1.7 angstrom A). The potential of the materials to undergo specific interactions with CO2 was measured by the isosteric heat adsorption. Further, we resynthesized zinc based IFPs, namely IFP-1 = Me), IFP-2 (R = Cl), IFP-3 (R = Br), and IFP-4 (R = Et), and cobalt based IFP-5 under MW-assisted conditions with higher yield. The transition from a nucleation phase to the pure crystalline material of IFP-1 in MW-assisted synthesis depends on reaction time. IFP-1, -3, and -5, which are synthesized by MW-assisted conditions, showed an enhancement of N-2 and CO2, compared to the analogous conventional electrical (CE) heating method based materials due to crystal defects. Y1 - 2015 U6 - https://doi.org/10.1021/acs.inorgchem.5b01952 SN - 0020-1669 SN - 1520-510X VL - 54 IS - 20 SP - 10073 EP - 10080 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Alrefai, Anas A1 - Mondal, Suvendu Sekhar A1 - Wruck, Alexander A1 - Kelling, Alexandra A1 - Schilde, Uwe A1 - Brandt, Philipp A1 - Janiak, Christoph A1 - Schoenfeld, Sophie A1 - Weber, Birgit A1 - Rybakowski, Lawrence A1 - Herrman, Carmen A1 - Brennenstuhl, Katlen A1 - Eidner, Sascha A1 - Kumke, Michael Uwe A1 - Behrens, Karsten A1 - Günter, Christina A1 - Müller, Holger A1 - Holdt, Hans-Jürgen T1 - Hydrogen-bonded supramolecular metal-imidazolate frameworks: gas sorption, magnetic and UV/Vis spectroscopic properties JF - Journal of Inclusion Phenomena and Macrocyclic Chemistry N2 - By varying reaction parameters for the syntheses of the hydrogen-bonded metal-imidazolate frameworks (HIF) HIF-1 and HIF-2 (featuring 14 Zn and 14 Co atoms, respectively) to increase their yields and crystallinity, we found that HIF-1 is generated in two different frameworks, named as HIF-1a and HIF-1b. HIF-1b is isostructural to HIF-2. We determined the gas sorption and magnetic properties of HIF-2. In comparison to HIF-1a (Brunauer-Emmett-Teller (BET) surface area of 471m(2) g(-1)), HIF-2 possesses overall very low gas sorption uptake capacities [BET(CO2) surface area=85m(2) g(-1)]. Variable temperature magnetic susceptibility measurement of HIF-2 showed antiferromagnetic exchange interactions between the cobalt(II) high-spin centres at lower temperature. Theoretical analysis by density functional theory confirmed this finding. The UV/Vis-reflection spectra of HIF-1 (mixture of HIF-1a and b), HIF-2 and HIF-3 (with 14 Cd atoms) were measured and showed a characteristic absorption band centered at 340nm, which was indicative for differences in the imidazolate framework. KW - Gas-sorption KW - Ligand design KW - Magnetic properties KW - Supramolecular chemistry KW - Solvothermal synthesis Y1 - 2019 U6 - https://doi.org/10.1007/s10847-019-00926-6 SN - 1388-3127 SN - 1573-1111 VL - 94 IS - 3-4 SP - 155 EP - 165 PB - Springer CY - Dordrecht ER -