TY  - JOUR
A1  - Bhattacharyya, Biswajit
A1  - Balischewski, Christian
A1  - Sperlich, Eric
A1  - Günter, Christina
A1  - Mies, Stefan
A1  - Kelling, Alexandra
A1  - Taubert, Andreas
T1  - N-Butyl Pyridinium Diiodido Argentate(I)
BT  - A One-Dimensional Ag-I Network with Superior Solid-State Ionic Conductivity at Room Temperature
JF  - Advanced materials interfaces
N2  - A new solid-state material, N-butyl pyridinium diiodido argentate(I), is synthesized using a simple and effective one-pot approach. In the solid state, the compound exhibits 1D ([AgI2](-))(n) chains that are stabilized by the N-butyl pyridinium cation. The 1D structure is further manifested by the formation of long, needle-like crystals, as revealed from electron microscopy. As the general composition is derived from metal halide-based ionic liquids, the compound has a low melting point of 100-101 degrees C, as confirmed by differential scanning calorimetry. Most importantly, the compound has a conductivity of 10(-6) S cm(-1) at room temperature. At higher temperatures the conductivity increases and reaches to 10(-4 )S cm(-1) at 70 degrees C. In contrast to AgI, however, the current material has a highly anisotropic 1D arrangement of the ionic domains. This provides direct and tuneable access to fast and anisotropic ionic conduction. The material is thus a significant step forward beyond current ion conductors and a highly promising prototype for the rational design of highly conductive ionic solid-state conductors for battery or solar cell applications.
KW  - AgI
KW  - ionic conductivity
KW  - Ionic liquids
KW  - thermal properties
Y1  - 2023
U6  - https://doi.org/10.1002/admi.202202363
SN  - 2196-7350
VL  - 10
IS  - 12
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - GEN
A1  - Bhattacharyya, Biswajit
A1  - Balischewski, Christian
A1  - Sperlich, Eric
A1  - Günter, Christina
A1  - Mies, Stefan
A1  - Kelling, Alexandra
A1  - Taubert, Andreas
T1  - N-Butyl Pyridinium Diiodido Argentate(I)
BT  - A One-Dimensional Ag-I Network with Superior Solid-State Ionic Conductivity at Room Temperature
T2  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - A new solid-state material, N-butyl pyridinium diiodido argentate(I), is synthesized using a simple and effective one-pot approach. In the solid state, the compound exhibits 1D ([AgI2](-))(n) chains that are stabilized by the N-butyl pyridinium cation. The 1D structure is further manifested by the formation of long, needle-like crystals, as revealed from electron microscopy. As the general composition is derived from metal halide-based ionic liquids, the compound has a low melting point of 100-101 degrees C, as confirmed by differential scanning calorimetry. Most importantly, the compound has a conductivity of 10(-6) S cm(-1) at room temperature. At higher temperatures the conductivity increases and reaches to 10(-4 )S cm(-1) at 70 degrees C. In contrast to AgI, however, the current material has a highly anisotropic 1D arrangement of the ionic domains. This provides direct and tuneable access to fast and anisotropic ionic conduction. The material is thus a significant step forward beyond current ion conductors and a highly promising prototype for the rational design of highly conductive ionic solid-state conductors for battery or solar cell applications.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1341 
KW  - AgI
KW  - ionic conductivity
KW  - Ionic liquids
KW  - thermal properties
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-604874
SN  - 1866-8372
IS  - 1341
ER  - 
TY  - JOUR
A1  - Sperlich, Eric
A1  - Kelling, Alexandra
A1  - Kwesiga, George
A1  - Schmidt, Bernd
T1  - Intermolecular interactions in the solid-state structures of isoflavones
BT  - the relationship between supramolecular structure, torsion angle, and macroscopic properties
JF  - CrystEngComm / The Royal Society of Chemistry
N2  - The molecular structures of three closely related isoflavones have been determined by single crystal X-ray diffraction and have been analysed by geometry matching with the CSD, Hirshfeld surface analysis and analysis of stacking interactions with the Aromatic Analyser program (CSD). The formation of the supramolecular structure by non-covalent interactions was studied and substantial differences in the macroscopic properties e.g., the solubility, were correlated with hydrogen bonding and pi-stacking interactions. Moreover, a correlation between the supramolecular structure, the torsion angle (between benzopyran group and aryl group), and macroscopic properties was determined in the three compounds.
Y1  - 2022
U6  - https://doi.org/10.1039/d2ce00169a
SN  - 1466-8033
VL  - 24
IS  - 26
SP  - 4731
EP  - 4739
PB  - Royal Society of Chemistry
CY  - London
ER  - 
TY  - JOUR
A1  - Wessig, Pablo
A1  - Badetko, Dominik
A1  - Czarnecki, Maciej
A1  - Wichterich, Lukas
A1  - Schmidt, Peter
A1  - Brudy, Cosima
A1  - Sperlich, Eric
A1  - Kelling, Alexandra
T1  - Studies toward the total synthesis of arylnaphthalene lignans via a Photo-Dehydro-Diels-Alder (PDDA) reaction
JF  - The journal of organic chemistry
N2  - An efficient method for the preparation of arylnaphthalene lignans (ANLs) was developed, which is based on thePhoto-Dehydro-DIELS-ALDER(PDDA) reaction. While intermolecular PDDA reactions turned out to be inefficient, theintramolecular variant using suberic acid as tether linking two aryl propiolic esters smoothly provided naphthalenophanes. Theirradiations were performed with a previously developed annular continuous-flow reactor and UVB lamps. In this way, the naturalproducts Alashinol D, Taiwanin C, and an unnamed ANL could be prepared.
Y1  - 2022
U6  - https://doi.org/10.1021/acs.joc.2c00195
SN  - 0022-3263
SN  - 1520-6904
VL  - 87
IS  - 9
SP  - 5904
EP  - 5915
PB  - American Chemical Society
CY  - Washington
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  - 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  - Fudickar, Werner
A1  - Metz, Melanie
A1  - Mai-Linde, Yasemin
A1  - Krüger, Tobias
A1  - Kelling, Alexandra
A1  - Sperlich, Eric
A1  - Linker, Torsten
T1  - Influence of functional groups on the ene reaction of singlet oxygen with 1,4-cyclohexadienes
JF  - Photochemistry and photobiology : the official journal of the American Society for Photobiology
N2  - The photooxygenation of 1,4-cyclohexadienes has been studied with a special focus on regio- and stereoselectivities. In all examples, only the methyl-substituted double bond undergoes an ene reaction with singlet oxygen, to afford hydroperoxides in moderate to good yields. We explain the high regioselectivities by a "large-group effect" of the adjacent quaternary stereocenter. Nitriles decrease the reactivity of singlet oxygen, presumably by quenching, but can stabilize proposed per-epoxide intermediates by polar interactions resulting in different stereoselectivities. Spiro lactams and lactones show an interesting effect on regio- and stereoselectivities of the ene reactions. Thus, singlet oxygen attacks the double bond preferentially anti to the carbonyl group, affording only one regioisomeric hydroperoxide. If the reaction occurs from the opposite face, the other regioisomer is exclusively formed by severe electrostatic repulsion in a perepoxide intermediate. We explain this unusual behavior by the fixed geometry of spiro compounds and call it a "spiro effect" in singlet oxygen ene reactions.
Y1  - 2021
U6  - https://doi.org/10.1111/php.13422
SN  - 0031-8655
SN  - 1751-1097
VL  - 97
IS  - 6
SP  - 1289
EP  - 1297
PB  - Wiley
CY  - Malden, Mass.
ER  - 
TY  - JOUR
A1  - Krüger, Tobias
A1  - Bramborg, Andrea
A1  - Kelling, Alexandra
A1  - Sperlich, Eric
A1  - Linker, Torsten
T1  - Birch Reduction of Arenes as an Easy Entry to γ-Spirolactones
JF  - European journal of organic chemistry
N2  - A convenient method for the synthesis of γ-spirolactones in only 2–3 steps is described. Birch reduction of inexpensive and commercially available aromatic carboxylic acids in the presence of ethylene oxide affords hydroxy acids, which undergo direct lactonization during work-up. Suitable precursors are methyl-substituted benzoic acids, naphthoic, and dicarboxylic acids. Subsequent hydrogenation proceeds smoothly with Pd/C as catalyst and saturated γ-spirolactones are isolated in excellent yields and stereoselectivities. Thus, up to 3 new stereogenic centers can be constructed as sole diastereomers from achiral benzoic acids. Furthermore, it is possible to control the degree of saturation with Raney nickel or Wilkinson's catalyst to obtain products with 1 double bond. Overall, more than 30 new γ-spirolactones have been synthesized in analytically pure form.
KW  - Arenes
KW  - Birch reduction
KW  - Hydrogenation
KW  - Lactones
KW  - Synthetic methods
Y1  - 2021
U6  - https://doi.org/10.1002/ejoc.202101018
SN  - 1434-193X
SN  - 1099-0690
VL  - 2021
IS  - 46
SP  - 6383
EP  - 6391
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Schwarze, Thomas
A1  - Sperlich, Eric
A1  - Müller, Thomas
A1  - Kelling, Alexandra
A1  - Holdt, Hans-Jürgen
T1  - Synthesis efforts of acyclic bis(monoalkylamino)maleonitriles and macrocyclic bis(dialkylamino)maleonitriles as fluorescent probes for cations and a new colorimetric copper(II) chemodosimeter
JF  - Helvetica chimica acta
N2  - In this article, we report on the synthesis of acyclic bis(monoalkylamino)maleonitriles and on the intended synthesis of macrocyclic bis(dialkylamino)maleonitriles to get fluorescent probes for cations. During our efforts to synthesize macrocyclic bis(dialkylamino)maleonitriles, we were only able to isolate macrocyclic bis(dialkylamino)-fumaronitriles. The synthesis of macrocyclic bis(dialkylamino)maleonitriles is challenging, due to the fact that bis-(dialkylamino)fumaronitriles are thermodynamically more stable than the corresponding bis(dialkylamino)-maleonitriles. Further, it turned out that the acyclic bis(monoalkylamino)maleonitriles and macrocyclic bis-(dialkylamino)fumaronitriles are no suitable tools to detect cations by a strong fluorescence enhancement. Further, only the bis(monoalkylamino)maleonitriles, which are bearing a 2-pyridyl unit as an additional complexing unit, are able to selectively recognize copper(II) by a color change from yellow to red.
KW  - copper
KW  - fumaronitrile
KW  - ligands
KW  - macrocycles
KW  - maleonitrile
Y1  - 2021
U6  - https://doi.org/10.1002/hlca.202100028
SN  - 1522-2675
VL  - 104
IS  - 6
SP  - e2100028
PB  - Wiley-VCH
CY  - Weinheim
ER  -