@article{Koetz2020,
  author    = {Koetz, Joachim},
  title     = {The Effect of Surface Modification of Gold Nanotriangles for Surface-Enhanced Raman Scattering Performance},
  series = {Nanomaterials},
  volume    = {10},
  journal   = {Nanomaterials},
  number    = {11},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2079-4991},
  doi       = {10.3390/nano10112187},
  pages     = {13},
  year      = {2020},
  abstract  = {A surface modification of ultraflat gold nanotriangles (AuNTs) with different shaped nanoparticles is of special relevance for surface-enhanced Raman scattering (SERS) and the photo-catalytic activity of plasmonic substrates. Therefore, different approaches are used to verify the flat platelet morphology of the AuNTs by oriented overgrowth with metal nanoparticles. The most important part for the morphological transformation of the AuNTs is the coating layer, containing surfactants or polymers. By using well established AuNTs stabilized by a dioctyl sodium sulfosuccinate (AOT) bilayer, different strategies of surface modification with noble metal nanoparticles are possible. On the one hand undulated superstructures were synthesized by in situ growth of hemispherical gold nanoparticles in the polyethyleneimine (PEI)-coated AOT bilayer of the AuNTs. On the other hand spiked AuNTs were obtained by a direct reduction of Au³⁺ ions in the AOT double layer in presence of silver ions and ascorbic acid as reducing agent. Additionally, crumble topping of the smooth AuNTs can be realized after an exchange of the AOT bilayer by hyaluronic acid, followed by a silver-ion mediated reduction with ascorbic acid. Furthermore, a decoration with silver nanoparticles after coating the AOT bilayer with the cationic surfactant benzylhexadecyldimethylammonium chloride (BDAC) can be realized. In that case the ultraviolet (UV)-absorption of the undulated Au@Ag nanoplatelets can be tuned depending on the degree of decoration with silver nanoparticles. Comparing the Raman scattering data for the plasmon driven dimerization of 4-nitrothiophenol (4-NTP) to 4,4′-dimercaptoazobenzene (DMAB) one can conclude that the most important effect of surface modification with a 75 times higher enhancement factor in SERS experiments becomes available by decoration with gold spikes.},
  language  = {en}
}
@article{FudickarMetzMaiLindeetal.2021,
  author    = {Fudickar, Werner and Metz, Melanie and Mai-Linde, Yasemin and Kr{\"u}ger, Tobias and Kelling, Alexandra and Sperlich, Eric and Linker, Torsten},
  title     = {Influence of functional groups on the ene reaction of singlet oxygen with 1,4-cyclohexadienes},
  series = {Photochemistry and photobiology : the official journal of the American Society for Photobiology},
  volume    = {97},
  journal   = {Photochemistry and photobiology : the official journal of the American Society for Photobiology},
  number    = {6},
  publisher = {Wiley},
  address   = {Malden, Mass.},
  issn      = {0031-8655},
  doi       = {10.1111/php.13422},
  pages     = {1289 -- 1297},
  year      = {2021},
  abstract  = {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.},
  language  = {en}
}
@article{AbbasVranicHoffmannetal.2018,
  author    = {Abbas, Ioana M. and Vranic, Marija and Hoffmann, Holger and El-Khatib, Ahmed H. and Montes-Bay{\´o}n, Mar{\´i}a and M{\"o}ller, Heiko Michael and Weller, Michael G.},
  title     = {Investigations of the Copper Peptide Hepcidin-25 by LC-MS/MS and NMR⁺},
  series = {International Journal of Molecular Sciences},
  volume    = {19},
  journal   = {International Journal of Molecular Sciences},
  number    = {8},
  publisher = {Molecular Diversity Preservation International},
  address   = {Basel},
  issn      = {1422-0067},
  doi       = {10.3390/ijms19082271},
  pages     = {16},
  year      = {2018},
  abstract  = {Hepcidin-25 was identified as themain iron regulator in the human body, and it by binds to the sole iron-exporter ferroportin. Studies showed that the N-terminus of hepcidin is responsible for this interaction, the same N-terminus that encompasses a small copper(II) binding site known as the ATCUN (amino-terminal Cu(II)- and Ni(II)-binding) motif. Interestingly, this copper-binding property is largely ignored in most papers dealing with hepcidin-25. In this context, detailed investigations of the complex formed between hepcidin-25 and copper could reveal insight into its biological role. The present work focuses on metal-bound hepcidin-25 that can be considered the biologically active form. The first part is devoted to the reversed-phase chromatographic separation of copper-bound and copper-free hepcidin-25 achieved by applying basic mobile phases containing 0.1\% ammonia. Further, mass spectrometry (tandemmass spectrometry (MS/MS), high-resolutionmass spectrometry (HRMS)) and nuclear magnetic resonance (NMR) spectroscopy were employed to characterize the copper-peptide. Lastly, a three-dimensional (3D)model of hepcidin-25with bound copper(II) is presented. The identification of metal complexes and potential isoforms and isomers, from which the latter usually are left undetected by mass spectrometry, led to the conclusion that complementary analytical methods are needed to characterize a peptide calibrant or referencematerial comprehensively. Quantitative nuclear magnetic resonance (qNMR), inductively-coupled plasma mass spectrometry (ICP-MS), ion-mobility spectrometry (IMS) and chiral amino acid analysis (AAA) should be considered among others.},
  language  = {en}
}
@misc{AbbasVranicHoffmannetal.2019,
  author    = {Abbas, Ioana M. and Vranic, Marija and Hoffmann, Holger and El-Khatib, Ahmed H. and Montes-Bay{\´o}n, Mar{\´i}a and M{\"o}ller, Heiko Michael and Weller, Michael G.},
  title     = {Investigations of the Copper Peptide Hepcidin-25 by LC-MS/MS and NMR⁺},
  series = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe},
  number    = {701},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-42792},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-427926},
  year      = {2019},
  abstract  = {Hepcidin-25 was identified as themain iron regulator in the human body, and it by binds to the sole iron-exporter ferroportin. Studies showed that the N-terminus of hepcidin is responsible for this interaction, the same N-terminus that encompasses a small copper(II) binding site known as the ATCUN (amino-terminal Cu(II)- and Ni(II)-binding) motif. Interestingly, this copper-binding property is largely ignored in most papers dealing with hepcidin-25. In this context, detailed investigations of the complex formed between hepcidin-25 and copper could reveal insight into its biological role. The present work focuses on metal-bound hepcidin-25 that can be considered the biologically active form. The first part is devoted to the reversed-phase chromatographic separation of copper-bound and copper-free hepcidin-25 achieved by applying basic mobile phases containing 0.1\% ammonia. Further, mass spectrometry (tandemmass spectrometry (MS/MS), high-resolutionmass spectrometry (HRMS)) and nuclear magnetic resonance (NMR) spectroscopy were employed to characterize the copper-peptide. Lastly, a three-dimensional (3D)model of hepcidin-25with bound copper(II) is presented. The identification of metal complexes and potential isoforms and isomers, from which the latter usually are left undetected by mass spectrometry, led to the conclusion that complementary analytical methods are needed to characterize a peptide calibrant or referencematerial comprehensively. Quantitative nuclear magnetic resonance (qNMR), inductively-coupled plasma mass spectrometry (ICP-MS), ion-mobility spectrometry (IMS) and chiral amino acid analysis (AAA) should be considered among others.},
  language  = {en}
}
@article{RajuKoetz2021,
  author    = {Raju, Rajarshi Roy and Koetz, Joachim},
  title     = {Inner rotation of Pickering Janus emulsions},
  series = {Nanomaterials : open access journal},
  volume    = {11},
  journal   = {Nanomaterials : open access journal},
  number    = {12},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2079-4991},
  doi       = {10.3390/nano11123312},
  pages     = {6},
  year      = {2021},
  abstract  = {Janus droplets were prepared by vortex mixing of three non-mixable liquids, i.e., olive oil, silicone oil and water, in the presence of gold nanoparticles (AuNPs) in the aqueous phase and magnetite nanoparticles (MNPs) in the olive oil. The resulting Pickering emulsions were stabilized by a red-colored AuNP layer at the olive oil/water interface and MNPs at the oil/oil interface. The core-shell droplets can be stimulated by an external magnetic field. Surprisingly, an inner rotation of the silicon droplet is observed when MNPs are fixed at the inner silicon droplet interface. This is the first example of a controlled movement of the inner parts of complex double emulsions by magnetic manipulation via interfacially confined magnetic nanoparticles.},
  language  = {en}
}
@article{Picconi2021,
  author    = {Picconi, David},
  title     = {Nonadiabatic quantum dynamics of the coherent excited state intramolecular proton transfer of 10-hydroxybenzo[h]quinoline},
  series = {Photochemical \& photobiological sciences},
  volume    = {20},
  journal   = {Photochemical \& photobiological sciences},
  number    = {11},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {1474-905X},
  doi       = {10.1007/s43630-021-00112-z},
  pages     = {1455 -- 1473},
  year      = {2021},
  abstract  = {The photoinduced nonadiabatic dynamics of the enol-keto isomerization of 10-hydroxybenzo[h]quinoline (HBQ) are studied computationally using high-dimensional quantum dynamics. The simulations are based on a diabatic vibronic coupling Hamiltonian, which includes the two lowest pi pi* excited states and a n pi* state, which has high energy in the Franck-Condon zone, but significantly stabilizes upon excited state intramolecular proton transfer. A procedure, applicable to large classes of excited state proton transfer reactions, is presented to parametrize this model using potential energies, forces and force constants, which, in this case, are obtained by time-dependent density functional theory. The wave packet calculations predict a time scale of 10-15 fs for the photoreaction, and reproduce the time constants and the coherent oscillations observed in time- resolved spectroscopic studies performed on HBQ. In contrast to the interpretation given to the most recent experiments, it is found that the reaction initiated by 1 pi pi* <- S-0 photoexcitation proceeds essentially on a single potential energy surface, and the observed coherences bear signatures of Duschinsky mode-mixing along the reaction path. The dynamics after the 2 pi pi* <- S-0 excitation are instead nonadiabatic, and the n pi* state plays a major role in the relaxation process. The simulations suggest a mainly active role of the proton in the isomerization, rather than a passive migration assisted by the vibrations of the benzoquinoline backbone. <br /> [GRAPHICS] <br /> .},
  language  = {en}
}
@article{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},
  series = {International journal of molecular sciences},
  volume    = {17},
  journal   = {International journal of molecular sciences},
  number    = {4},
  publisher = {MDPI},
  address   = {Basel},
  doi       = {10.3390/ijms17040596},
  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{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}
}
@article{MeyerRaberEbertetal.2015,
  author    = {Meyer, S. and Raber, G. and Ebert, Franziska and Leffers, L. and M{\"u}ller, Sandra Marie and Taleshi, M. S. and Francesconi, Kevin A. and Schwerdtle, Tanja},
  title     = {In vitro toxicological characterisation of arsenic-containing fatty acids and three of their metabolites},
  series = {Toxicology research},
  volume    = {5},
  journal   = {Toxicology research},
  number    = {4},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {2045-4538},
  doi       = {10.1039/c5tx00122f},
  pages     = {1289 -- 1296},
  year      = {2015},
  abstract  = {Arsenic-containing fatty acids are a group of fat-soluble arsenic species (arsenolipids) which are present in marine fish and other seafood. Recently, it has been shown that arsenic-containing hydrocarbons, another group of arsenolipids, exert toxicity in similar concentrations comparable to arsenite although the toxic modes of action differ. Hence, a risk assessment of arsenolipids is urgently needed. In this study the cellular toxicity of a saturated (AsFA 362) and an unsaturated (AsFA 388) arsenic-containing fatty acid and three of their proposed metabolites (DMAV, DMAPr and thio-DMAPr) were investigated in human liver cells (HepG2). Even though both arsenic-containing fatty acids were less toxic as compared to arsenic-containing hydrocarbons and arsenite, significant effects were observable at μM concentrations. DMAV causes effects in a similar concentration range and it could be seen that it is metabolised to its highly toxic thio analogue thio-DMAV in HepG2 cells. Nevertheless, DMAPr and thio-DMAPr did not exert any cytotoxicity. In summary, our data indicate that risks to human health related to the presence of arsenic-containing fatty acids in marine food cannot be excluded. This stresses the need for a full in vitro and in vivo toxicological characterisation of these arsenolipids.},
  language  = {en}
}
@misc{MeyerRaberEbertetal.2015,
  author    = {Meyer, S. and Raber, G. and Ebert, Franziska and Leffers, L. and M{\"u}ller, Sandra Marie and Taleshi, M. S. and Francesconi, Kevin A. and Schwerdtle, Tanja},
  title     = {In vitro toxicological characterisation of arsenic-containing fatty acids and three of their metabolites},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82008},
  year      = {2015},
  abstract  = {Arsenic-containing fatty acids are a group of fat-soluble arsenic species (arsenolipids) which are present in marine fish and other seafood. Recently, it has been shown that arsenic-containing hydrocarbons, another group of arsenolipids, exert toxicity in similar concentrations comparable to arsenite although the toxic modes of action differ. Hence, a risk assessment of arsenolipids is urgently needed. In this study the cellular toxicity of a saturated (AsFA 362) and an unsaturated (AsFA 388) arsenic-containing fatty acid and three of their proposed metabolites (DMAV, DMAPr and thio-DMAPr) were investigated in human liver cells (HepG2). Even though both arsenic-containing fatty acids were less toxic as compared to arsenic-containing hydrocarbons and arsenite, significant effects were observable at μM concentrations. DMAV causes effects in a similar concentration range and it could be seen that it is metabolised to its highly toxic thio analogue thio-DMAV in HepG2 cells. Nevertheless, DMAPr and thio-DMAPr did not exert any cytotoxicity. In summary, our data indicate that risks to human health related to the presence of arsenic-containing fatty acids in marine food cannot be excluded. This stresses the need for a full in vitro and in vivo toxicological characterisation of these arsenolipids.},
  language  = {en}
}