@misc{PacholskiAgarwalBalderasValadez2016,
  author    = {Pacholski, Claudia and Agarwal, Vivechana and Balderas-Valadez, Ruth Fabiola},
  title     = {Fabrication of porous silicon-based optical sensors using metal-assisted chemical etching},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-394426},
  pages     = {21430 -- 21434},
  year      = {2016},
  abstract  = {Optical biosensors based on porous silicon were fabricated by metal assisted chemical etching. Thereby double layered porous silicon structures were obtained consisting of porous pillars with large pores on top of a porous silicon layer with smaller pores. These structures showed a similar sensing performance in comparison to electrochemically produced porous silicon interferometric sensors.},
  language  = {en}
}
@misc{ZabelWinterKellingetal.2016,
  author    = {Zabel, Andr{\´e} and Winter, Alette and Kelling, Alexandra and Schilde, Uwe and Strauch, Peter},
  title     = {Tetrabromidocuprates(II)-Synthesis, Structure and EPR},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-91470},
  pages     = {14},
  year      = {2016},
  abstract  = {Metal-containing ionic liquids (ILs) are of interest for a variety of technical applications, e.g., particle synthesis and materials with magnetic or thermochromic properties. In this paper we report the synthesis of, and two structures for, some new tetrabromidocuprates(II) with several "onium" cations in comparison to the results of electron paramagnetic resonance (EPR) spectroscopic analyses. The sterically demanding cations were used to separate the paramagnetic Cu(II) ions for EPR measurements. The EPR hyperfine structure in the spectra of these new compounds is not resolved, due to the line broadening resulting from magnetic exchange between the still-incomplete separated paramagnetic Cu(II) centres. For the majority of compounds, the principal g values (g|| and gK) of the tensors could be determined and information on the structural changes in the [CuBr4]2- anions can be obtained. The complexes have high potential, e.g., as ionic liquids, as precursors for the synthesis of copper bromide particles, as catalytically active or paramagnetic ionic liquids.},
  language  = {en}
}
@misc{SchildeKellingUmbreenetal.2016,
  author    = {Schilde, Uwe and Kelling, Alexandra and Umbreen, Sumaira and Linker, Torsten},
  title     = {Crystal structures of three bicyclic carbohydrate derivatives},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-100833},
  pages     = {6},
  year      = {2016},
  abstract  = {The title compounds, [(1R,3R,4R,5R,6S)-4,5-bis­(acet­yloxy)-7-oxo-2-oxabi­cyclo[4.2.0]octan-3-yl]methyl acetate, C14H18O8, (I), [(1S,4R,5S,6R)-5-acet­yloxy-7-hy­droxy­imino-2-oxobi­cyclo­[4.2.0]octan-4-yl acetate, C11H15NO6, (II), and [(3aR,5R,6R,7R,7aS)-6,7-bis­(acet­yloxy)-2-oxo­octa­hydro­pyrano[3,2-b]pyrrol-5-yl]methyl acetate, C14H19NO8, (III), are stable bicyclic carbohydrate derivatives. They can easily be synthesized in a few steps from commercially available glycals. As a result of the ring strain from the four-membered rings in (I) and (II), the conformations of the carbohydrates deviate strongly from the ideal chair form. Compound (II) occurs in the boat form. In the five-membered lactam (III), on the other hand, the carbohydrate adopts an almost ideal chair conformation. As a result of the distortion of the sugar rings, the configurations of the three bicyclic carbohydrate derivatives could not be determined from their NMR coupling constants. From our three crystal structure determinations, we were able to establish for the first time the absolute configurations of all new stereocenters of the carbohydrate rings.},
  language  = {en}
}
@misc{SchulzeKoetz2016,
  author    = {Schulze, Nicole and Koetz, Joachim},
  title     = {Kinetically Controlled Growth of Gold Nanotriangles in a Vesicular Template Phase by Adding a Strongly Alternating Polyampholyte},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-98380},
  pages     = {22},
  year      = {2016},
  abstract  = {This paper is focused on the temperature dependent synthesis of gold nanotriangles in a vesicular template phase, containing phosphatidylcholin and AOT, by adding the strongly alternating polyampholyte PalPhBisCarb. UV-vis absorption spectra in combination with TEM micrographs show that flat gold nanoplatelets are formed predominantly in presence of the polyampholyte at 45 °C. The formation of triangular and hexagonal nanoplatelets can be directly influenced by the kinetic approach, i.e., by varying the polyampholyte dosage rate at 45 °C. Corresponding zeta potential measurements indicate that a temperature dependent adsorption of the polyampholyte on the {111} faces will induce the symmetry breaking effect, which is responsible for the kinetically controlled hindered vertical and preferred lateral growth of the nanoplatelets.},
  language  = {en}
}
@misc{SchneiderWeigertLesnyaketal.2016,
  author    = {Schneider, Ralf and Weigert, Florian and Lesnyak, Vladimir and Leubner, Susanne and Lorenz, Tommy and Behnke, Thomas and Dubavik, Aliaksei and Joswig, Jan-Ole and Resch-Genger, Ute and Gaponik, Nikolai and Eychm{\"u}ller, Alexander},
  title     = {pH and concentration dependence of the optical properties of thiol-capped CdTe nanocrystals in water and D2O},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-395143},
  pages     = {10},
  year      = {2016},
  abstract  = {The optical properties of semiconductor nanocrystals (SC NCs) are largely controlled by their size and surface chemistry, i.e., the chemical composition and thickness of inorganic passivation shells and the chemical nature and number of surface ligands as well as the strength of their bonds to surface atoms. The latter is particularly important for CdTe NCs, which - together with alloyed CdxHg1-xTe - are the only SC NCs that can be prepared in water in high quality without the need for an additional inorganic passivation shell. Aiming at a better understanding of the role of stabilizing ligands for the control of the application-relevant fluorescence features of SC NCs, we assessed the influence of two of the most commonly used monodentate thiol ligands, thioglycolic acid (TGA) and mercaptopropionic acid (MPA), on the colloidal stability, photoluminescence (PL) quantum yield (QY), and PL decay behavior of a set of CdTe NC colloids. As an indirect measure for the strength of the coordinative bond of the ligands to SC NC surface atoms, the influence of the pH (pD) and the concentration on the PL properties of these colloids was examined in water and D2O and compared to the results from previous dilution studies with a set of thiol-capped Cd1-xHgxTe SC NCs in D2O. As a prerequisite for these studies, the number of surface ligands was determined photometrically at different steps of purification after SC NC synthesis with Ellman's test. Our results demonstrate ligand control of the pH-dependent PL of these SC NCs, with MPA-stabilized CdTe NCs being less prone to luminescence quenching than TGA-capped ones. For both types of CdTe colloids, ligand desorption is more pronounced in H2O compared to D2O, underlining also the role of hydrogen bonding and solvent molecules.},
  language  = {en}
}
@misc{ToepferTremblay2016,
  author    = {T{\"o}pfer, Kai and Tremblay, Jean Christophe},
  title     = {How surface reparation prevents catalytic oxidation of carbon monoxide on atomic gold at defective magnesium oxide surfaces},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-394978},
  pages     = {8},
  year      = {2016},
  abstract  = {In this contribution, we study using first principles the co-adsorption and catalytic behaviors of CO and O2 on a single gold atom deposited at defective magnesium oxide surfaces. Using cluster models and point charge embedding within a density functional theory framework, we simulate the CO oxidation reaction for Au1 on differently charged oxygen vacancies of MgO(001) to rationalize its experimentally observed lack of catalytic activity. Our results show that: (1) co-adsorption is weakly supported at F0 and F2+ defects but not at F1+ sites, (2) electron redistribution from the F0 vacancy via the Au1 cluster to the adsorbed molecular oxygen weakens the O2 bond, as required for a sustainable catalytic cycle, (3) a metastable carbonate intermediate can form on defects of the F0 type, (4) only a small activation barrier exists for the highly favorable dissociation of CO2 from F0, and (5) the moderate adsorption energy of the gold atom on the F0 defect cannot prevent insertion of molecular oxygen inside the defect. Due to the lack of protection of the color centers, the surface becomes invariably repaired by the surrounding oxygen and the catalytic cycle is irreversibly broken in the first oxidation step.},
  language  = {en}
}
@misc{LiebigSarhanPrietzeletal.2016,
  author    = {Liebig, Ferenc and Sarhan, Radwan Mohamed and Prietzel, Claudia Christina and Reinecke, Antje and Koetz, Joachim},
  title     = {"Green" gold nanotriangles: synthesis, purification by polyelectrolyte/micelle depletion flocculation and performance in surface-enhanced Raman scattering},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-394430},
  pages     = {33561 -- 33568},
  year      = {2016},
  abstract  = {The aim of this study was to develop a one-step synthesis of gold nanotriangles (NTs) in the presence of mixed phospholipid vesicles followed by a separation process to isolate purified NTs. Negatively charged vesicles containing AOT and phospholipids, in the absence and presence of additional reducing agents (polyampholytes, polyanions or low molecular weight compounds), were used as a template phase to form anisotropic gold nanoparticles. Upon addition of the gold chloride solution, the nucleation process is initiated and both types of particles, i.e., isotropic spherical and anisotropic gold nanotriangles, are formed simultaneously. As it was not possible to produce monodisperse nanotriangles with such a one-step procedure, the anisotropic nanoparticles needed to be separated from the spherical ones. Therefore, a new type of separation procedure using combined polyelectrolyte/micelle depletion flocculation was successfully applied. As a result of the different purification steps, a green colored aqueous dispersion was obtained containing highly purified, well-defined negatively charged flat nanocrystals with a platelet thickness of 10 nm and an edge length of about 175 nm. The NTs produce promising results in surface-enhanced Raman scattering.},
  language  = {en}
}
@misc{WessigHilleKumkeetal.2016,
  author    = {Wessig, Pablo and Hille, Carsten and Kumke, Michael Uwe and Meiling, Till Thomas and Behrends, Nicole and Eisold, Ursula},
  title     = {Two-photon FRET pairs based on coumarin and DBD dyes},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-394445},
  pages     = {33510 -- 33513},
  year      = {2016},
  abstract  = {The synthesis and photophysical properties of two new FRET pairs based on coumarin as a donor and DBD dye as an acceptor are described. The introduction of a bromo atom dramatically increases the two-photon excitation (2PE) cross section providing a 2PE-FRET system, which is also suitable for 2PE-FLIM.},
  language  = {en}
}
@misc{SteeplesKellingSchildeetal.2016,
  author    = {Steeples, Elliot and Kelling, Alexandra and Schilde, Uwe and Esposito, Davide},
  title     = {Amino acid-derived N-heterocyclic carbene palladium complexes for aqueous phase Suzuki-Miyaura couplings},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-394488},
  pages     = {4922 -- 4930},
  year      = {2016},
  abstract  = {In this work, three ligands produced from amino acids were synthesized and used to produce five bis- and PEPPSI-type palladium-NHC complexes using a novel synthesis route from sustainable starting materials. Three of these complexes were used as precatalysts in the aqueous-phase Suzuki-Miyaura coupling of various substrates displaying high activity. TEM and mercury poisoning experiments provide evidence for Pd-nanoparticle formation stabilized in water.},
  language  = {en}
}
@misc{MeilingCywińskiBald2016,
  author    = {Meiling, Till Thomas and Cywiński, Piotr J. and Bald, Ilko},
  title     = {White carbon: Fluorescent carbon nanoparticles with tunable quantum yield in a reproducible green synthesis},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-97087},
  year      = {2016},
  abstract  = {In this study, a new reliable, economic, and environmentally-friendly one-step synthesis is established to obtain carbon nanodots (CNDs) with well-defined and reproducible photoluminescence (PL) properties via the microwave-assisted hydrothermal treatment of starch and Tris-acetate-EDTA (TAE) buffer as carbon sources. Three kinds of CNDs are prepared using different sets of above mentioned starting materials. The as-synthesized CNDs: C-CND (starch only), N-CND 1 (starch in TAE) and N-CND 2 (TAE only) exhibit highly homogenous PL and are ready to use without need for further purification. The CNDs are stable over a long period of time (>1 year) either in solution or as freeze-dried powder. Depending on starting material, CNDs with PL quantum yield (PLQY) ranging from less than 1\% up to 28\% are obtained. The influence of the precursor concentration, reaction time and type of additives on the optical properties (UV-Vis absorption, PL emission spectrum and PLQY) is carefully investigated, providing insight into the chemical processes that occur during CND formation. Remarkably, upon freeze-drying the initially brown CND-solution turns into a non-fluorescent white/slightly brown powder which recovers PL in aqueous solution and can potentially be applied as fluorescent marker in bio-imaging, as a reduction agent or as a photocatalyst.},
  language  = {en}
}