@article{SperlichKoeckerling2021,
  author    = {Sperlich, Eric and K{\"o}ckerling, Martin},
  title     = {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},
  series = {ChemistryOpen},
  volume    = {10},
  journal   = {ChemistryOpen},
  number    = {2},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {2191-1363},
  doi       = {10.1002/open.202000266},
  pages     = {248 -- 254},
  year      = {2021},
  abstract  = {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.},
  language  = {en}
}
@article{BreternitzLehmannBarnettetal.2019,
  author    = {Breternitz, Joachim and Lehmann, Frederike and Barnett, Sarah A. and Nowell, Harriott and Schorr, Susan},
  title     = {Zur Rolle der Iodid-Methylammonium-Interaktion in der Ferroelektrizit{\"a}t in CH3NH3PbI3},
  series = {Angewandte Chemie},
  volume    = {132},
  journal   = {Angewandte Chemie},
  number    = {1},
  publisher = {John Wiley \& Sons, Inc.},
  address   = {New Jersey},
  pages     = {5},
  year      = {2019},
  abstract  = {Ihre außergew{\"o}hnlich hohen Konversionseffizienzen von {\"u}ber 20 \% und die einfache Zellherstellung machen Hybridperowskite zu heißen Kandidaten f{\"u}r alternative Solarzellenmaterialien. CH3NH3PbI3 als Archetyp dieser Materialklasse besitzt außergew{\"o}hnliche Eigenschaften wie eine sehr effiziente Umwandlung von Solarenergie, wobei besonders Ferroelektrizit{\"a}t als m{\"o}gliche Erkl{\"a}rung in den Fokus ger{\"u}ckt ist. Diese erfordert allerdings eine nicht-zentrosymmetrische Kristallstruktur als notwendige Voraussetzung. Wir stellen hier eine Erkl{\"a}rung des Symmetriebruchs in diesem Material auf kristallographischem, d. h. fernordnungs-basiertem, Wege vor. W{\"a}hrend das Molek{\"u}lkation CH3NH3+ intrinsisch polar ist, ist es extrem fehlgeordnet und kann deshalb nicht die einzige Erkl{\"a}rung darstellen. Es verzerrt allerdings das umgebende Kristallgitter und ruft dadurch eine Verschiebung der Iod-Atome von den zentrosymmetrischen Positionen hervor.},
  language  = {de}
}
@misc{BreternitzLehmannBarnettetal.2019,
  author    = {Breternitz, Joachim and Lehmann, Frederike and Barnett, Sarah A. and Nowell, Harriott and Schorr, Susan},
  title     = {Zur Rolle der Iodid-Methylammonium-Interaktion in der Ferroelektrizit{\"a}t in CH3NH3PbI3},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {1},
  issn      = {1866-8372},
  doi       = {10.1002/ange.201910599},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-525674},
  pages     = {7},
  year      = {2019},
  abstract  = {Ihre außergew{\"o}hnlich hohen Konversionseffizienzen von {\"u}ber 20 \% und die einfache Zellherstellung machen Hybridperowskite zu heißen Kandidaten f{\"u}r alternative Solarzellenmaterialien. CH3NH3PbI3 als Archetyp dieser Materialklasse besitzt außergew{\"o}hnliche Eigenschaften wie eine sehr effiziente Umwandlung von Solarenergie, wobei besonders Ferroelektrizit{\"a}t als m{\"o}gliche Erkl{\"a}rung in den Fokus ger{\"u}ckt ist. Diese erfordert allerdings eine nicht-zentrosymmetrische Kristallstruktur als notwendige Voraussetzung. Wir stellen hier eine Erkl{\"a}rung des Symmetriebruchs in diesem Material auf kristallographischem, d. h. fernordnungs-basiertem, Wege vor. W{\"a}hrend das Molek{\"u}lkation CH3NH3+ intrinsisch polar ist, ist es extrem fehlgeordnet und kann deshalb nicht die einzige Erkl{\"a}rung darstellen. Es verzerrt allerdings das umgebende Kristallgitter und ruft dadurch eine Verschiebung der Iod-Atome von den zentrosymmetrischen Positionen hervor.},
  language  = {de}
}
@misc{BreternitzLehmannBarnettetal.2019,
  author    = {Breternitz, Joachim and Lehmann, Frederike and Barnett, Sarah A. and Nowell, Harriott and Schorr, Susan},
  title     = {Role of the Iodide-methylammonium interaction in the ferroelectricity of CH3NH3PbI3},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {1},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-51822},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-518227},
  pages     = {7},
  year      = {2019},
  abstract  = {Excellent conversion efficiencies of over 20\% and facile cell production have placed hybrid perovskites at the forefront of novel solar cell materials, with CH3NH3PbI3 being an archetypal compound. The question why CH3NH3PbI3 has such extraordinary characteristics, particularly a very efficient power conversion from absorbed light to electrical power, is hotly debated, with ferroelectricity being a promising candidate. This does, however, require the crystal structure to be non-centrosymmetric and we herein present crystallographic evidence as to how the symmetry breaking occurs on a crystallographic and, therefore, long-range level. Although the molecular cation CH3NH3+ is intrinsically polar, it is heavily disordered and this cannot be the sole reason for the ferroelectricity. We show that it, nonetheless, plays an important role, as it distorts the neighboring iodide positions from their centrosymmetric positions.},
  language  = {en}
}
@article{SenfRuprechtKishanietal.2018,
  author    = {Senf, Deborah and Ruprecht, Colin and Kishani, Saina and Matic, Aleksandar and Toriz, Guillermo and Gatenholm, Paul and Wagberg, Lars and Pfrengle, Fabian},
  title     = {Tailormade polysaccharides with defined branching patterns},
  series = {Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition},
  volume    = {57},
  journal   = {Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition},
  number    = {37},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1433-7851},
  doi       = {10.1002/anie.201806871},
  pages     = {11987 -- 11992},
  year      = {2018},
  abstract  = {The heterogeneous nature of non-cellulosic polysaccharides, such as arabinoxylan, makes it difficult to correlate molecular structure with macroscopic properties. To study the impact of specific structural features of the polysaccharides on crystallinity or affinity to other cell wall components, collections of polysaccharides with defined repeating units are required. Herein, a chemoenzymatic approach to artificial arabinoxylan polysaccharides with systematically altered branching patterns is described. The polysaccharides were obtained by glycosynthase-catalyzed polymerization of glycosyl fluorides derived from arabinoxylan oligosaccharides. X-ray diffraction and adsorption experiments on cellulosic surfaces revealed that the physicochemical properties of the synthetic polysaccharides strongly depend on the specific nature of their substitution patterns. The artificial polysaccharides allow structure-property relationship studies that are not accessible by other means.},
  language  = {en}
}
@misc{BringmannMutanyattaComarMaksimenkaetal.2008,
  author    = {Bringmann, Gerhard and Mutanyatta-Comar, Joan and Maksimenka, Katja and Wanjohi, John M. and Heydenreich, Matthias and Brun, Reto and M{\"u}ller, Werner E. G. and Peter, Martin and Midiwo, Jacob O. and Yenesew, Abiy},
  title     = {Joziknipholones A and B : the First Dimeric Phenylanthraquinones, from the Roots of Bulbine frutescens},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-42638},
  year      = {2008},
  abstract  = {From the roots of the African plant Bulbine frutescens (Asphodelaceae), two unprecedented novel dimeric phenylanthraquinones, named joziknipholones A and B, possessing axial and centrochirality, were isolated, together with six known compounds. Structural elucidation of the new metabolites was achieved by spectroscopic and chiroptical methods, by reductive cleavage of the central bond between the monomeric phenylanthraquinone and -anthrone portions with sodium dithionite, and by quantum chemical CD calculations. Based on the recently revised absolute axial configuration of the parent phenylanthraquinones, knipholone and knipholone anthrone, the new dimers were attributed to possess the P-configuration (i.e., with the acetyl portions below the anthraquinone plane) at both axes in the case of joziknipholone A, whereas in joziknipholone B, the knipholone part was found to be M-configured. Joziknipholones A and B are active against the chloroquine resistant strain K1 of the malaria pathogen, Plasmodium falciparum, and show moderate activity against murine leukemic lymphoma L5178y cells.},
  language  = {en}
}