@article{BuecheleChaoOstermannetal.2019,
  author    = {B{\"u}chele, Dominique and Chao, Madlen and Ostermann, Markus and Leenen, Matthias and Bald, Ilko},
  title     = {Multivariate chemometrics as a key tool for prediction of K and Fe in a diverse German agricultural soil-set using EDXRF},
  series = {Scientific Reports},
  volume    = {9},
  journal   = {Scientific Reports},
  publisher = {Macmillan Publishers Limited, part of Springer Nature},
  address   = {London},
  issn      = {2045-2322},
  doi       = {10.1038/s41598-019-53426-5},
  pages     = {11},
  year      = {2019},
  abstract  = {Within the framework of precision agriculture, the determination of various soil properties is moving into focus, especially the demand for sensors suitable for in-situ measurements. Energy-dispersive X-ray fluorescence (EDXRF) can be a powerful tool for this purpose. In this study a huge diverse soil set (n = 598) from 12 different study sites in Germany was analysed with EDXRF. First, a principal component analysis (PCA) was performed to identify possible similarities among the sample set. Clustering was observed within the four texture classes clay, loam, silt and sand, as clay samples contain high and sandy soils low iron mass fractions. Furthermore, the potential of uni- and multivariate data evaluation with partial least squares regression (PLSR) was assessed for accurate determination of nutrients in German agricultural samples using two calibration sample sets. Potassium and iron were chosen for testing the performance of both models. Prediction of these nutrients in 598 German soil samples with EDXRF was more accurate using PLSR which is confirmed by a better overall averaged deviation and PLSR should therefore be preferred.},
  language  = {en}
}
@article{LiebigHenningSarhanetal.2019,
  author    = {Liebig, Ferenc and Henning, Ricky and Sarhan, Radwan Mohamed and Prietzel, Claudia Christina and Schmitt, Clemens Nikolaus Zeno and Bargheer, Matias and Koetz, Joachim},
  title     = {A simple one-step procedure to synthesise gold nanostars in concentrated aqueous surfactant solutions},
  series = {RSC Advances},
  volume    = {9},
  journal   = {RSC Advances},
  publisher = {RSC Publishing},
  address   = {London},
  issn      = {2046-2069},
  doi       = {10.1039/C9RA02384D},
  pages     = {23633 -- 23641},
  year      = {2019},
  abstract  = {Due to the enhanced electromagnetic field at the tips of metal nanoparticles, the spiked structure of gold nanostars (AuNSs) is promising for surface-enhanced Raman scattering (SERS). Therefore, the challenge is the synthesis of well designed particles with sharp tips. The influence of different surfactants, i.e., dioctyl sodium sulfosuccinate (AOT), sodium dodecyl sulfate (SDS), and benzylhexadecyldimethylammonium chloride (BDAC), as well as the combination of surfactant mixtures on the formation of nanostars in the presence of Ag⁺ ions and ascorbic acid was investigated. By varying the amount of BDAC in mixed micelles the core/spike-shell morphology of the resulting AuNSs can be tuned from small cores to large ones with sharp and large spikes. The concomitant red-shift in the absorption toward the NIR region without losing the SERS enhancement enables their use for biological applications and for time-resolved spectroscopic studies of chemical reactions, which require a permanent supply with a fresh and homogeneous solution. HRTEM micrographs and energy-dispersive X-ray (EDX) experiments allow us to verify the mechanism of nanostar formation according to the silver underpotential deposition on the spike surface in combination with micelle adsorption.},
  language  = {en}
}
@article{KirsteBrietzkeHoldtetal.2019,
  author    = {Kirste, Matthias and Brietzke, Thomas Martin and Holdt, Hans-J{\"u}rgen and Schilde, Uwe},
  title     = {The crystal structure of 1,12-diazaperylene, C₁₈H₁₀N₂},
  series = {Zeitschrift f{\"u}r Kristallographie - New Crystal Structures},
  volume    = {234},
  journal   = {Zeitschrift f{\"u}r Kristallographie - New Crystal Structures},
  number    = {6},
  publisher = {De Gruyter},
  address   = {Berlin},
  issn      = {2196-7105},
  doi       = {10.1515/NCRS-2019-0385},
  pages     = {1255 -- 1257},
  year      = {2019},
  abstract  = {C₁₈H₁₀N₂, monoclinic, P2₁/c (no. 14), a=7.9297(9) {\AA}, b=11.4021(14) {\AA}, c=13.3572(15) {\AA}, β=105.363(8)°, V =1164.5(2) {\AA}³, Z =4, Rgt(F)=0.0325, wRref(F²)=0.0774, T =210(2) K.},
  language  = {en}
}
@article{RajuLiebigHessetal.2019,
  author    = {Raju, Rajarshi Roy and Liebig, Ferenc and Hess, Andreas and Schlaad, Helmut and Koetz, Joachim},
  title     = {Temperature-triggered reversible breakdown of polymer-stabilized olive},
  series = {RSC Advances},
  volume    = {9},
  journal   = {RSC Advances},
  number    = {35},
  publisher = {RSC Publishing},
  address   = {London},
  issn      = {2046-2069},
  doi       = {10.1039/c9ra03463c},
  pages     = {19271 -- 19277},
  year      = {2019},
  abstract  = {A one-step moderate energy vibrational emulsification method was successfully employed to produce thermo-responsive olive/silicone-based Janus emulsions stabilized by poly(N,N-diethylacrylamide) carrying 0.7 mol\% oleoyl side chains. Completely engulfed emulsion droplets remained stable at room temperature and could be destabilized on demand upon heating to the transition temperature of the polymeric stabilizer. Time-dependent light micrographs demonstrate the temperature-induced breakdown of the Janus droplets, which opens new aspects of application, for instance in biocatalysis.},
  language  = {en}
}
@article{KruegerKellingLinkeretal.2019,
  author    = {Krueger, Tobias and Kelling, Alexandra and Linker, Torsten and Schilde, Uwe},
  title     = {Crystal structures of three cyclohexane‑based γ‑spirolactams},
  series = {BMC Chemistry},
  volume    = {13},
  journal   = {BMC Chemistry},
  number    = {69},
  publisher = {Springer International Publishing},
  address   = {Basel},
  issn      = {2661-801X},
  doi       = {10.1186/s13065-019-0586-7},
  pages     = {9},
  year      = {2019},
  abstract  = {The title compounds, 2-azaspiro[4.5]deca-1-one, C₉H₁₅NO, (1a), cis-8-methyl-2-azaspiro[4.5]deca-1-one, C₁₀H₁₇NO, (1b), and trans-8-methyl-2-azaspiro[4.5]deca-1-one, C₁₀H₁₇NO, (1c), were synthesized from benzoic acids 2 in only 3 steps in high yields. Crystallization from n-hexane afforded single crystals, suitable for X-ray diffraction. Thus, the configurations, conformations, and interesting crystal packing effects have been determined unequivocally. The bicyclic skeleton consists of a lactam ring, attached by a spiro junction to a cyclohexane ring. The lactam ring adopts an envelope conformation and the cyclohexane ring has a chair conformation. The main difference between compound 1b and compound 1c is the position of the carbonyl group on the 2-pyrrolidine ring with respect to the methyl group on the 8-position of the cyclohexane ring, which is cis (1b) or trans (1c). A remarkable feature of all three compounds is the existence of a mirror plane within the molecule. Given that all compounds crystallize in centrosymmetric space groups, the packing always contains interesting enantiomer-like pairs. Finally, the structures are stabilized by intermolecular N-H···O hydrogen bonds.},
  language  = {en}
}
@article{HeckKanehiraKneippetal.2019,
  author    = {Heck, Christian and Kanehira, Yuya and Kneipp, Janina and Bald, Ilko},
  title     = {Amorphous Carbon Generation as a Photocatalytic Reaction on DNA-Assembled Gold and Silver Nanostructures},
  series = {Molecules},
  volume    = {24},
  journal   = {Molecules},
  number    = {12},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1420-3049},
  doi       = {10.3390/molecules24122324},
  pages     = {10},
  year      = {2019},
  abstract  = {Background signals from in situ-formed amorphous carbon, despite not being fully understood, are known to be a common issue in few-molecule surface-enhanced Raman scattering (SERS). Here, discrete gold and silver nanoparticle aggregates assembled by DNA origami were used to study the conditions for the formation of amorphous carbon during SERS measurements. Gold and silver dimers were exposed to laser light of varied power densities and wavelengths. Amorphous carbon prevalently formed on silver aggregates and at high power densities. Time-resolved measurements enabled us to follow the formation of amorphous carbon. Silver nanolenses consisting of three differently-sized silver nanoparticles were used to follow the generation of amorphous carbon at the single-nanostructure level. This allowed observation of the many sharp peaks that constitute the broad amorphous carbon signal found in ensemble measurements. In conclusion, we highlight strategies to prevent amorphous carbon formation, especially for DNA-assembled SERS substrates.},
  language  = {en}
}