Contact

Speaker

Prof. Dr. Sven Doye

Deputy Speaker

Prof. Dr. Rüdiger Beckhaus

Coordination

Sonja Weiz

Publications

This website is currently under maintenance. The list of publications is incomplete.

2020

  • M. Warsitz and S. Doye, "Two‐Step Procedure for the Synthesis of 1,2,3,4‐Tetrahydro‐quinolines," European Journal of Organic Chemistry, vol. 2020, iss. 45, pp. 6997-7014, 2020.
    @article{Warsitz2020a, abstract = {A new two-step procedure that includes an initial regioselective intermolecular hydroaminoalkylation of ortho-chlorostyrenes with N-methylanilines and a subsequent intramolecular Buchwald–Hartwig amination gives direct access to 1,2,3,4-tetrahydroquinolines. The hydroaminoalkylation reaction of the ortho-chlorostyrenes is catalyzed by a 2,6-bis(phenylamino)pyridinato titanium complex which delivers the linear regioisomers with high selectivities. In addition, the formation of unexpected dihydroaminoalkylation products from styrenes and N-methylanilines is reported.},
      author = {Warsitz, Michael and Doye, Sven},
      doi = {10.1002/ejoc.202001337},
      file = {:C$\backslash$:/Users/Sonja Weiz/Nextcloud/GRK 2226/Publikationen/ejoc.202001337.pdf:pdf},
      issn = {1434-193X},
      journal = {European Journal of Organic Chemistry},
      keywords = {Amination,Amines,Palladium,Tetrahydroquinolines,Titanium},
      month = {dec},
      number = {45},
      pages = {6997--7014},
      title = {{Two‐Step Procedure for the Synthesis of 1,2,3,4‐Tetrahydro‐quinolines}},
      url = {https://onlinelibrary.wiley.com/doi/10.1002/ejoc.202001337},
      volume = {2020},
      year = {2020} }
  • M. Siemer, G. Tomaschun, T. Klüner, P. Christopher, and K. Al-Shamery, "Insights into Spectator-Directed Catalysis: CO Adsorption on Amine-Capped Platinum Nanoparticles on Oxide Supports," ACS Applied Materials & Interfaces, vol. 12, iss. 24, pp. 27765-27776, 2020.
    @article{Siemer2020,
      author = {Siemer, Michael and Tomaschun, Gabriele and Kl{\"{u}}ner, Thorsten and Christopher, Phillip and Al-Shamery, Katharina},
      doi = {10.1021/acsami.0c06086},
      file = {:C$\backslash$:/Users/Sonja Weiz/Nextcloud/GRK 2226/Publikationen/acsami.0c06086.pdf:pdf},
      issn = {1944-8244},
      journal = {ACS Applied Materials {\&} Interfaces},
      month = {jun},
      number = {24},
      pages = {27765--27776},
      title = {{Insights into Spectator-Directed Catalysis: CO Adsorption on Amine-Capped Platinum Nanoparticles on Oxide Supports}},
      url = {https://pubs.acs.org/doi/10.1021/acsami.0c06086},
      volume = {12},
      year = {2020} }
  • T. Kaper, M. Fischer, M. Warsitz, R. Zimmering, R. Beckhaus, and S. Doye, "Intermolecular Hydroaminoalkylation of Propadiene," Chemistry – A European Journal, vol. 26, iss. 63, pp. 14300-14304, 2020.
    @article{Kaper2020, abstract = {Intermolecular hydroaminoalkylation reactions of propadiene with selected secondary amines take place in the presence of a 2,6-bis(phenylamino)pyridinato titanium catalyst. The corresponding products, synthetically useful allylamines, are formed in convincing yields and with high selectivities. In addition, propadiene easily inserts into the titanium-carbon bond of a titanaaziridine.},
      author = {Kaper, Tobias and Fischer, Malte and Warsitz, Michael and Zimmering, Ren{\'{e}} and Beckhaus, Ruediger and Doye, Sven},
      doi = {10.1002/chem.202003484},
      file = {:C$\backslash$:/Users/Sonja Weiz/Nextcloud/GRK 2226/Publikationen/chem.202003484.pdf:pdf},
      issn = {0947-6539},
      journal = {Chemistry – A European Journal},
      keywords = {C−H activation,allenes,amines,hydroaminoalkylation,titanium},
      month = {nov},
      number = {63},
      pages = {14300--14304},
      title = {{Intermolecular Hydroaminoalkylation of Propadiene}},
      url = {https://onlinelibrary.wiley.com/doi/10.1002/chem.202003484},
      volume = {26},
      year = {2020} }
  • M. Warsitz and S. Doye, "Linear Hydroaminoalkylation Products from Alkyl‐Substituted Alkenes," Chemistry – A European Journal, vol. 26, iss. 66, pp. 15121-15125, 2020.
    @article{Warsitz2020, abstract = {The regioselective conversion of alkyl-substituted alkenes into linear hydroaminoalkylation products represents a strongly desirable synthetic transformation. In particular, such conversions of N-methylamine derivatives are of great scientific interest, because they would give direct access to important amines with unbranched alkyl chains. Herein, we present a new one-pot procedure that includes an initial alkene hydroaminoalkylation with an $\alpha$-silylated amine substrate and a subsequent protodesilylation reaction that delivers linear hydroaminoalkylation products with high selectivity from simple alkyl-substituted alkenes. For that purpose, new titanium catalysts have been developed, which are able to activate the $\alpha$-C−H bond of more challenging $\alpha$-silylated amine substrates. In addition, a direct relationship between the ligand structure of the new catalysts and the obtained regioselectivity is described.},
      author = {Warsitz, Michael and Doye, Sven},
      doi = {10.1002/chem.202003223},
      file = {:C$\backslash$:/Users/Sonja Weiz/Nextcloud/GRK 2226/Publikationen/chem.202003223.pdf:pdf},
      issn = {0947-6539},
      journal = {Chemistry – A European Journal},
      keywords = {alkenes,amines,hydroaminoalkylation,titanium},
      month = {nov},
      number = {66},
      pages = {15121--15125},
      title = {{Linear Hydroaminoalkylation Products from Alkyl‐Substituted Alkenes}},
      url = {https://onlinelibrary.wiley.com/doi/10.1002/chem.202003223},
      volume = {26},
      year = {2020} }
  • J. Küppers and N. Mitschke, "Über den anaeroben Abbau von Kohlenwasserstoffen in Bakterien," Mitt. Umweltchem. Ökotox., vol. 26, pp. 85-89, 2020.
    @article{Kuppers2020a,
      author = {K{\"{u}}ppers, J and Mitschke, N},
      file = {:C$\backslash$:/Users/Sonja Weiz/Nextcloud/GRK 2226/Publikationen/K{\"{u}}ppers{\_}Mitschke{\_}Mitt{\_}03{\_}2020.pdf:pdf},
      journal = {Mitt. Umweltchem. {\"{O}}kotox.},
      keywords = {Bakterien,Kohlenwasserstoffe,Sa,anaerober Abbau},
      pages = {85--89},
      title = {{{\"{U}}ber den anaeroben Abbau von Kohlenwasserstoffen in Bakterien}},
      url = {https://www.gdch.de/fileadmin/downloads/Netzwerk{\_}und{\_}Strukturen/Fachgruppen/Umweltchemie{\_}OEkotoxikologie/mblatt/2020/b4h320.pdf},
      volume = {26},
      year = {2020} }
  • A. Markovic, L. Gerhards, P. Sander, C. Dosche, T. Klüner, R. Beckhaus, and G. Wittstock, "Electronic Transitions in Different Redox States of Trinuclear 5,6,11,12,17,18‐Hexaazatrinaphthylene‐Bridged Titanium Complexes: Spectroelectrochemistry and Quantum Chemistry," ChemPhysChem, vol. 21, iss. 22, pp. 2506-2514, 2020.
    @article{Markovic2020, abstract = {Multinuclear transition metal complexes bridged by ligands with extended $\pi$-electronic systems show a variety of complex electronic transitions and electron transfer reactions. While a systematic understanding of the photochemistry and electrochemistry has been attained for binuclear complexes, much less is known about trinuclear complexes such as hexaphenyl-5,6,11,12,17,18-hexaazatrinaphthylene-tristitanocene [(Cp2Ti)3HATN(Ph)6]. The voltammogram of [(Cp2Ti)3HATN(Ph)6] shows six oxidation and three reduction waves. Solution spectra of [(Cp2Ti)3HATN(Ph)6] and of the electrochemically formed oxidation products show electronic transitions in the UV, visible and the NIR ranges. Density functional theory (DFT) and linear response time-dependent DFT show that the three formally titanium(II) centers transfer an electron to the HATN ligand in the ground state. The optically excited transitions occur exclusively between ligand-centered orbitals. The charged titanium centers only provide an electrostatic frame to the extended $\pi$-electronic system. Complete active self-consistent field (CASSCF) calculation on a structurally simplified model compound, which considers the multi-reference character imposed by the three titanium centers, can provide an interpretation of the experimentally observed temperature-dependent magnetic behavior of the different redox states of the title compound in full consistency with the interpretation of the electronic spectra.},
      author = {Markovic, Aleksandra and Gerhards, Luca and Sander, Pia and Dosche, Carsten and Kl{\"{u}}ner, Thorsten and Beckhaus, R{\"{u}}diger and Wittstock, Gunther},
      doi = {10.1002/cphc.202000547},
      file = {:C$\backslash$:/Users/Sonja Weiz/Nextcloud/GRK 2226/Publikationen/cphc.202000547.pdf:pdf},
      issn = {1439-4235},
      journal = {ChemPhysChem},
      keywords = {HATN ligand,intervalence charge transfer,quantum chemistry,spectroelectrochemistry,trinuclear Ti complexes},
      month = {nov},
      number = {22},
      pages = {2506--2514},
      title = {{Electronic Transitions in Different Redox States of Trinuclear 5,6,11,12,17,18‐Hexaazatrinaphthylene‐Bridged Titanium Complexes: Spectroelectrochemistry and Quantum Chemistry}},
      url = {https://onlinelibrary.wiley.com/doi/10.1002/cphc.202000547},
      volume = {21},
      year = {2020} }
  • [article] bibtex
    N. Mitschke, R. Jarling, R. Rabus, J. Christoffers, and H. Wilkes, "Metabolites of the anaerobic degradation of diethyl ether by denitrifying betaproteobacterium strain HxN1," Organic and Biomolecular Chemistry, vol. 18, iss. 36, pp. 7098-7109, 2020.
    @article{Mitschke2020a, abstract = {The constitutions of five metabolites formed during co-metabolic, anaerobic degradation of diethyl ether by the denitrifying betaproteobacteriumAromatoleumsp. strain HxN1 were elucidated by comparison of mass spectrometric and gas chromatographic data with those of synthetic reference standards. Furthermore, the absolute configurations of two stereogenic centers in the metabolites were established. Based on these results a degradation pathway for diethyl ether byAromatoleumsp. HxN1 analogous to that ofn-hexane is proposed. Synthesis of both enantiomers of methyl (E)-4-ethoxy-2-pentenoate was accomplished by etherification of ethyl (R)- or (S)-lactate, followed by hydrolysis of the ester group and reduction to furnish 2-ethoxy-1-propanol. The primary alcohol was converted by a Swern oxidation followed by a Horner-Wadsworth-Emmons reaction to methyl (E)-4-ethoxy-2-pentenoate that was finally hydrogenated to methyl 4-ethoxypentanoate. Methyl (S)-4-ethoxy-3-oxopentanoate was prepared by conversion of (S)-2-ethoxypropanoyl chloride with Meldrum's acid. Reduction of the resulting $\beta$-oxoester with NaBH4or baker's yeast gave both diastereoisomers of methyl 4-ethoxy-3-hydroxypentanoate. The stereocenter at C-3 of the main diastereoisomer produced with baker's yeast was determined by Mosher ester analysis to be (R)-configurated. Dimethyl 2-(1-ethoxyethyl)succinate was prepared by Michael addition of nitroethane to diethyl maleate, followed by conjugate addition of sodium ethanolate, hydrolysis and esterification with diazomethane.},
      author = {Mitschke, Nico and Jarling, Ren{\'{e}} and Rabus, Ralf and Christoffers, Jens and Wilkes, Heinz},
      doi = {10.1039/d0ob01419b},
      file = {:C$\backslash$:/Users/Sonja Weiz/Nextcloud/GRK 2226/Publikationen/10.1039D0OB01419B.pdf:pdf},
      issn = {14770520},
      journal = {Organic and Biomolecular Chemistry},
      number = {36},
      pages = {7098--7109},
      pmid = {32897282},
      title = {{Metabolites of the anaerobic degradation of diethyl ether by denitrifying betaproteobacterium strain HxN1}},
      volume = {18},
      year = {2020} }
  • L. Li and G. Hilt, "Regiodivergent DH or HD Addition to Alkenes: Deuterohydrogenation versus Hydrodeuterogenation," Organic Letters, vol. 22, iss. 4, pp. 1628-1632, 2020.
    @article{Li2020, abstract = {The regioselective and regiodivergent addition of H-D to a variety of 1,1-diarylalkenes was realized utilizing selectively deuterated dihydroaromatic compounds, which were generated by cobalt catalysis. The reaction was initiated by catalytic amounts of BF3{\textperiodcentered}Et2O by abstracting hydride or deuteride ions from the respective dihydroaromatic reducing agents and led to a highly regioselective incorporation of deuterium and hydrogen at the desired positions of the starting material.},
      author = {Li, Luomo and Hilt, Gerhard},
      doi = {10.1021/acs.orglett.0c00213},
      file = {:C$\backslash$:/Users/Sonja Weiz/Nextcloud/GRK 2226/Publikationen/acs.orglett.0c00213.pdf:pdf},
      issn = {1523-7060},
      journal = {Organic Letters},
      keywords = {GRK2226},
      mendeley-tags = {GRK2226},
      month = {feb},
      number = {4},
      pages = {1628--1632},
      pmid = {32043886},
      title = {{Regiodivergent DH or HD Addition to Alkenes: Deuterohydrogenation versus Hydrodeuterogenation}},
      url = {https://pubs.acs.org/doi/10.1021/acs.orglett.0c00213},
      volume = {22},
      year = {2020} }
  • N. Mitschke, J. Christoffers, and H. Wilkes, "A Straightforward Synthesis of Trideuterated α-Terpinene for Mechanistic Studies," European Journal of Organic Chemistry, vol. 31, pp. 4893-4899, 2020.
    @article{Mitschke2020, abstract = {Regiospecifically trideuterated (2,6,6-2H3)-$\alpha$-terpinene was prepared in six steps and with a deuterium incorporation of {\textgreater}99 {\%} in 24 {\%} yield from 1,4-cyclohexanedione monoethylene ketal. The synthetic procedure involved twofold cross-coupling reactions of alkylcuprates (lithium dimethylcuprate and chloromagnesium cyano(isopropyl)cuprate, respectively) with enol triflates to introduce the alkyl substituents on the 1,3-cyclohexadiene backbone. By changing the alkylcuprates, the synthetic approach could serve as a prototype for the synthesis of various 1,4-dialkyl-substituted 1,3-cyclohexadiene derivatives, which could be deuterium-labeled as well, for example for mechanistic studies.},
      author = {Mitschke, Nico and Christoffers, Jens and Wilkes, Heinz},
      doi = {10.1002/ejoc.202000684},
      file = {:C$\backslash$:/Users/Sonja Weiz/Nextcloud/GRK 2226/Publikationen/ejoc.202000684.pdf:pdf},
      issn = {1434193X},
      journal = {European Journal of Organic Chemistry},
      keywords = {Biodegradation,Cross-coupling,Deuteration,GRK2226,Hydrocarbons,Terpenes},
      mendeley-tags = {GRK2226},
      month = {aug},
      pages = {4893--4899},
      title = {{A Straightforward Synthesis of Trideuterated $\alpha$-Terpinene for Mechanistic Studies}},
      url = {http://doi.wiley.com/10.1002/ejoc.202000684},
      volume = {31},
      year = {2020} }
  • M. Rosien, I. Töben, M. Schmidtmann, R. Beckhaus, and S. Doye, "Titanium‐Catalyzed Hydroaminoalkylation of Ethylene," Chemistry – A European Journal, vol. 26, iss. 10, pp. 2138-2142, 2020.
    @article{Rosien2020, abstract = {The first examples of titanium-catalyzed hydroaminoalkylation reactions of ethylene with secondary amines are presented. The reactions can be achieved with various titanium catalysts and they do not require the use of high pressure equipment. In addition, the first solid-state structure of a titanapyrrolidine that is formed by insertion of an alkene into the Ti−C bond of a titanaaziridine is reported.},
      author = {Rosien, Michael and T{\"{o}}ben, Iris and Schmidtmann, Marc and Beckhaus, R{\"{u}}diger and Doye, Sven},
      doi = {10.1002/chem.201904502},
      file = {:C$\backslash$:/Users/Sonja Weiz/Nextcloud/GRK 2226/Publikationen/chem.201904502.pdf:pdf},
      issn = {0947-6539},
      journal = {Chemistry – A European Journal},
      keywords = {GRK2226,amination,amines,ethylene,hydroaminoalkylation,titanium},
      mendeley-tags = {GRK2226},
      month = {feb},
      number = {10},
      pages = {2138--2142},
      pmid = {31799706},
      title = {{Titanium‐Catalyzed Hydroaminoalkylation of Ethylene}},
      url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/chem.201904502},
      volume = {26},
      year = {2020} }
  • J. Küppers, N. Mitschke, S. Heyen, R. Rabus, H. Wilkes, and J. Christoffers, "Metabolites of the Anaerobic Degradation of n ‐Hexane by Denitrifying Betaproteobacterium Strain HxN1," ChemBioChem, vol. 21, iss. 3, pp. 373-380, 2020.
    @article{Kuppers2020, abstract = {The constitutions of seven metabolites formed during anaerobic degradation of n-hexane by the denitrifying betaproteobacterium strain HxN1 were elucidated by comparison of their GC and MS data with those of synthetic reference standards. The synthesis of 4-methyloctanoic acid derivatives was accomplished by the conversion of 2-methylhexanoyl chloride with Meldrum's acid. The $\beta$-oxoester was reduced with NaBH4, the hydroxy group was eliminated, and the double bond was displaced to yield the methyl esters of 4-methyl-3-oxooctanoate, 3-hydroxy-4-methyloctanoate, (E)-4-methyl-2-octenoate, and (E)- and (Z)-4-methyl-3-octenoate. The methyl esters of 2-methyl-3-oxohexanoate and 3-hydroxy-2-methylhexanoate were similarly prepared from butanoyl chloride and Meldrum's acid. However, methyl (E)-2-methyl-2-hexenoate was prepared by Horner–Wadsworth–Emmons reaction, followed by isomerization to methyl (E)-2-methyl-3-hexenoate. This investigation, with the exception of 4-methyl-3-oxooctanoate, which was not detectable in the cultures, completes the unambiguous identification of all intermediates of the anaerobic biodegradation of n-hexane to 2-methyl-3-oxohexanoyl coenzyme A (CoA), which is then thiolytically cleaved to butanoyl-CoA and propionyl-CoA; these two metabolites are further transformed according to established pathways.},
      author = {K{\"{u}}ppers, Julian and Mitschke, Nico and Heyen, Simone and Rabus, Ralf and Wilkes, Heinz and Christoffers, Jens},
      doi = {10.1002/cbic.201900375},
      file = {:C$\backslash$:/Users/Sonja Weiz/Nextcloud/GRK 2226/Publikationen/cbic.201900375.pdf:pdf},
      issn = {1439-4227},
      journal = {ChemBioChem},
      keywords = {C−H activation,GRK2226,alkanes,anaerobic degradation,metabolism,structure elucidation},
      mendeley-tags = {GRK2226},
      month = {feb},
      number = {3},
      pages = {373--380},
      pmid = {31294892},
      title = {{Metabolites of the Anaerobic Degradation of n ‐Hexane by Denitrifying Betaproteobacterium Strain HxN1}},
      url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/cbic.201900375},
      volume = {21},
      year = {2020} }

2019

  • F. Bizzotto, J. Quinson, A. Zana, J. J. K. Kirkensgaard, A. Dworzak, M. Oezaslan, and M. Arenz, "Ir nanoparticles with ultrahigh dispersion as oxygen evolution reaction (OER) catalysts: synthesis and activity benchmarking," Catalysis Science & Technology, vol. 9, iss. 22, pp. 6345-6356, 2019.
    @article{Bizzotto2019, abstract = {In this work, we present a facile and straightforward approach to synthesize, activate and benchmark small, i.e. 1.6 nm in diameter, Ir nanoparticles (NP) as oxygen evolution reaction (OER) catalysts.},
      author = {Bizzotto, Francesco and Quinson, Jonathan and Zana, Alessandro and Kirkensgaard, Jacob J. K. and Dworzak, Alexandra and Oezaslan, Mehtap and Arenz, Matthias},
      doi = {10.1039/C9CY01728C},
      file = {:C$\backslash$:/Users/Weiz/Nextcloud/GRK 2226/Publikationen/bizzotto2019.pdf:pdf},
      issn = {2044-4753},
      journal = {Catalysis Science {\&} Technology},
      keywords = {?},
      mendeley-tags = {?},
      number = {22},
      pages = {6345--6356},
      publisher = {Royal Society of Chemistry},
      title = {{Ir nanoparticles with ultrahigh dispersion as oxygen evolution reaction (OER) catalysts: synthesis and activity benchmarking}},
      url = {http://xlink.rsc.org/?DOI=C9CY01728C},
      volume = {9},
      year = {2019} }
  • L. Buschbeck, A. Markovic, G. Wittstock, and J. Christoffers, "Diaminoterephthalate–α-lipoic acid conjugates with fluorinated residues," Beilstein Journal of Organic Chemistry, vol. 15, pp. 981-991, 2019.
    @article{Buschbeck2019, abstract = {Two bifunctional diaminoterephthalate (DAT) fluorescence dyes were prepared in a three-step sequence including one deprotection reaction. One functional unit is $\alpha$-lipoic acid (ALA) for binding the dye to gold surfaces. It was introduced to the DAT scaffold by an amidation reaction. The other functional unit is a para -(trifluoromethyl)benzyl group for facile detection of the surface-bound material by X-ray photoelectron spectroscopy (XPS). This residue was introduced by reductive amination of the DAT scaffold with the respective benzaldehyde derivative. In one compound (60{\%} yield over three steps) the ALA unit is directly bound to the DAT as a relatively electron-withdrawing amide. In solution (CH 2 Cl 2 ), this material shows strong fluorescence (quantum yield 57{\%} with emission at 495 nm, absorption maximum at 420 nm). The other compound (57{\%} yield over three steps) possesses a propylene spacer between the ALA and the DAT units for electronic decoupling, thus, bathochromic shifts are observed (absorption at 514 nm, emission at 566 nm). The quantum yield is, however, lower (4{\%}). Self-assembled monolayers on a gold surface of both compounds were prepared and characterized by high-resolution XPS of the C 1s, O 1s, S 2p, N 1s and F 1s emissions. The high signal-to-noise ratios of the F 1s peaks indicated that trifluoromethylation is an excellent tool for the detection of surface-bound materials by XPS.},
      author = {Buschbeck, Leon and Markovic, Aleksandra and Wittstock, Gunther and Christoffers, Jens},
      doi = {10.3762/bjoc.15.96},
      file = {:C$\backslash$:/Users/Weiz/Nextcloud/GRK 2226/Publikationen/1860-5397-15-96.pdf:pdf},
      issn = {1860-5397},
      journal = {Beilstein Journal of Organic Chemistry},
      keywords = {?,Chromophore,Diaminoterephthalate,Fluorescence dye,Fluorine surface marker,Lipoic acid,Self-assembled monolayers},
      mendeley-tags = {?},
      month = {apr},
      pages = {981--991},
      title = {{Diaminoterephthalate–$\alpha$-lipoic acid conjugates with fluorinated residues}},
      url = {https://www.beilstein-journals.org/bjoc/articles/15/96},
      volume = {15},
      year = {2019} }
  • J. Chen, L. Mohrhusen, G. Ali, S. Li, K. Y. Chung, K. Al-Shamery, and P. S. Lee, "Electrochemical Mechanism Investigation of Cu 2 MoS 4 Hollow Nanospheres for Fast and Stable Sodium Ion Storage," Advanced Functional Materials, vol. 29, iss. 7, p. 1807753, 2019.
    @article{Chen2019, abstract = {Sodium ion batteries (SIBs) are promising alternatives to lithium ion batteries with advantages of cost effectiveness. Metal sulfides as emerging SIB anodes have relatively high electronic conductivity and high theoretical capacity, however, large volume change during electrochemical testing often leads to unsatisfactory electrochemical performance. Herein bimetallic sulfide Cu 2 MoS 4 (CMS) with layered crystal structures are prepared with glucose addition (CMS1), resulting in the formation of hollow nanospheres that endow large interlayer spacing, benefitting the rate performance and cycling stability. The electrochemical mechanisms of CMS1 are investigated using ex situ X-ray photoelectron spectroscopy and in situ X-ray absorption spectroscopy, revealing the conversion-based mechanism in carbonate electrolyte and intercalation-based mechanism in ether-electrolyte, thus allowing fast and reversible Na + storage. With further introduction of reduced graphene oxide (rGO), CMS1–rGO composites are obtained, maintaining the hollow structure of CMS1. CMS1–rGO delivers excellent rate performance (258 mAh g −1 at 50 mA g −1 and 131.9 mAh g −1 at 5000 mA g −1 ) and notably enhanced cycling stability (95.6{\%} after 2000 cycles). A full cell SIB is assembled by coupling CMS1–rGO with Na 3 V 2 (PO 4 ) 3 -based cathode, delivering excellent cycling stability (75.5{\%} after 500 cycles). The excellent rate performance and cycling stability emphasize the advantage of CMS1–rGO toward advanced SIB full cells assembly.},
      author = {Chen, Jingwei and Mohrhusen, Lars and Ali, Ghulam and Li, Shaohui and Chung, Kyung Yoon and Al-Shamery, Katharina and Lee, Pooi See},
      doi = {10.1002/adfm.201807753},
      file = {:C$\backslash$:/Users/Weiz/Nextcloud/GRK 2226/Publikationen/adfm.201807753.pdf:pdf},
      issn = {1616301X},
      journal = {Advanced Functional Materials},
      keywords = {GRK2226,bimetallic sulfides,in situ X-ray absorption spectroscopy,sodium ion battery anodes},
      mendeley-tags = {GRK2226},
      month = {feb},
      number = {7},
      pages = {1807753},
      title = {{Electrochemical Mechanism Investigation of Cu 2 MoS 4 Hollow Nanospheres for Fast and Stable Sodium Ion Storage}},
      url = {http://doi.wiley.com/10.1002/adfm.201807753},
      volume = {29},
      year = {2019} }
  • X. Gong, J. Chen, S. Li, L. Mohrhusen, K. Al‐Shamery, and P. S. Lee, "Vanadium Oxide Nanosheets for Flexible Dendrite‐Free Hybrid Aluminium‐Lithium‐Ion Batteries with Excellent Cycling Performance," Batteries & Supercaps, vol. 2, iss. 3, pp. 205-212, 2019.
    @article{Gong2019, abstract = {Aluminum (Al)-ion batteries can be an attractive alternative to lithium-ion batteries because of low costs, high volumetric capacities and dendrite-free formation when Al is used as anode. However, there are limited cathode materials for Al-ion batteries that can deliver satisfactory electrochemical performance, especially cycling stability. The major reason for that is the sluggish kinetics of ion intercalation/deintercalation, resulting from large coulombic attraction between Al3+ and cathodes. Herein, a concept of hybrid Al-Li-ion batteries is proposed to circumvent the poor Al3+ ions insertion/extraction kinetics in Al-ion batteries, and maintain the dendrite-free characteristics of Al-ion batteries. The high volumetric capacity (32.5 mAh/cm(3) at 100 mA/cm(3), based on the total volume of cathode), enhanced rate capability (21.5 mAh/cm(3) at 1000 mA/cm(3)) and excellent cycling performance (70.1{\%} retention after 3000 cycles) have been achieved in the hybrid Al-Li-ion battery composed of vanadium oxide nanosheets on carbon fibers as cathode and Al as anode in a mixed {\{}[{\}}EMIM]{\{}[{\}}Cl]/AlCl3/LiCl electrolyte. Combining with the good flexibility of cathode and anode, the hybrid Al-Li-ion battery maintains structural and capacity stability under different bending angles. This study unveils a safe, cost-effective and flexible hybrid Al-Li-ion battery that presents highly competitive advantages among various energy storage devices.},
      author = {Gong, Xuefei and Chen, Jingwei and Li, Shaohui and Mohrhusen, Lars and Al‐Shamery, Katharina and Lee, Pooi See},
      doi = {10.1002/batt.201800108},
      file = {:C$\backslash$:/Users/Weiz/Nextcloud/GRK 2226/Publikationen/batt.201800108.pdf:pdf},
      issn = {2566-6223},
      journal = {Batteries {\&} Supercaps},
      keywords = {?},
      mendeley-tags = {?},
      month = {mar},
      number = {3},
      pages = {205--212},
      title = {{Vanadium Oxide Nanosheets for Flexible Dendrite‐Free Hybrid Aluminium‐Lithium‐Ion Batteries with Excellent Cycling Performance}},
      url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/batt.201800108},
      volume = {2},
      year = {2019} }
  • T. Kaper and S. Doye, "Hydroaminoalkylation/Buchwald-Hartwig amination sequences for the synthesis of benzo-annulated seven-membered nitrogen heterocycles," Tetrahedron, vol. 75, iss. 32, pp. 4343-4350, 2019.
    @article{Kaper2019, abstract = {Reaction sequences consisting of an initial intermolecular titanium-catalyzed hydroaminoalkylation of a suitably ortho-bromophenyl-substituted alkene and a subsequent intramolecular Buchwald-Hartwig amination are used for the synthesis of benzazepine, benzoxazepine, and benzothiazepine derivatives. While in the latter two cases, the hydroaminoalkylation products obtained from an allyl (2-bromophenyl) ether or an allyl (2-bromophenyl) thioether must be purified prior to the subsequent palladium-catalyzed amination step, both reactions can be combined to an efficient one-pot procedure for the synthesis of 2,3,4,5-tetrahydrobenzo[b]azepines when 4-(2-bromophenyl)-1-butene and various N-methylanilines are used as the starting materials.},
      author = {Kaper, Tobias and Doye, Sven},
      doi = {10.1016/j.tet.2019.04.041},
      file = {:C$\backslash$:/Users/Weiz/Downloads/kaper2019.pdf:pdf},
      issn = {14645416},
      journal = {Tetrahedron},
      keywords = {Amines,Azepanes,Hydroaminoalkylation,Palladium,Titanium},
      number = {32},
      pages = {4343--4350},
      publisher = {Elsevier Ltd},
      title = {{Hydroaminoalkylation/Buchwald-Hartwig amination sequences for the synthesis of benzo-annulated seven-membered nitrogen heterocycles}},
      url = {https://doi.org/10.1016/j.tet.2019.04.041},
      volume = {75},
      year = {2019} }
  • J. Kräuter, L. Mohrhusen, T. Thiedemann, M. Willms, and K. Al-Shamery, "Activation of Small Organic Molecules on Ti2+-Rich TiO2 Surfaces: Deoxygenation vs. C–C Coupling," Zeitschrift für Naturforschung A, vol. 74, iss. 8, pp. 697-707, 2019.
    @article{Krauter2019, abstract = {Rutile TiO 2 is an important model system for understanding the adsorption and conversion of molecules on transition metal oxide catalysts. In the last decades, point defects, such as oxygen vacancies and Ti 3+ interstitials, exhibited an important influence on the reaction of oxygen and oxygen-containing molecules on titania surfaces. In brief, partially reduced TiO 2 containing a significant amount of Ti 3+ is often more active for the conversion of such molecules. In this study, we investigate an even higher reduced surface prepared by argon ion bombardment of a rutile TiO 2 (110) single crystal. By X-ray photoelectron spectroscopy we show that, besides Ti 4+ , this surface is almost equally dominated by Ti 3+ and Ti 2+ . To probe the reactivity of these highly reduced surfaces, we have adsorbed two different classes of oxygen-containing molecules and utilized temperature programmed reaction spectroscopy to investigate the conversion. While alcohols (in this case methanol) already show a defect-dependent partial conversion in a deoxygenation reaction on the (stochiometric or slightly reduced) rutile TiO 2 (110) surface, ketones (e.g. acetone) are usually not converted on the rutile TiO 2 (110) surface independent on the bulk defect density. Here, we present a nearly full conversion for both molecules via deoxygenation reactions and reductive C–C coupling, forming different hydrocarbons at different temperatures between 375 K and 640 K on the sputtered Ti 2+ rich surface.},
      author = {Kr{\"{a}}uter, Jessica and Mohrhusen, Lars and Thiedemann, Tim and Willms, Michael and Al-Shamery, Katharina},
      doi = {10.1515/zna-2019-0135},
      file = {:C$\backslash$:/Users/Weiz/Nextcloud/GRK 2226/Publikationen/[18657109 - Zeitschrift f{\"{u}}r Naturforschung A] Activation of Small Organic Molecules on Ti2+-Rich TiO2 Surfaces Deoxygenation vs. C–C Coupling.pdf:pdf},
      issn = {1865-7109},
      journal = {Zeitschrift f{\"{u}}r Naturforschung A},
      keywords = {110,GRK2226,abstract,activating organic molecules,an important model system,c,c coupling,deoxygenation,reductive coupling,reorganization,reoxidation,rutile tio 2,rutile tio 2 is,surface},
      mendeley-tags = {GRK2226},
      month = {aug},
      number = {8},
      pages = {697--707},
      title = {{Activation of Small Organic Molecules on Ti2+-Rich TiO2 Surfaces: Deoxygenation vs. C–C Coupling}},
      url = {http://www.degruyter.com/view/j/zna.2019.74.issue-8/zna-2019-0135/zna-2019-0135.xml},
      volume = {74},
      year = {2019} }
  • J. Küppers, P. Becker, R. Jarling, M. Dörries, N. Cakić, M. Schmidtmann, J. Christoffers, R. Rabus, and H. Wilkes, "Stereochemical Insights into the Anaerobic Degradation of 4‐Isopropylbenzoyl‐CoA in the Denitrifying Bacterium Strain pCyN1," Chemistry – A European Journal, vol. 25, iss. 18, pp. 4722-4731, 2019.
    @article{Kuppers2019a, abstract = {The constitutions and absolute configurations of two previously unknown intermediates, (1S,2S,4S)-2-hydroxy-4-isopropylcyclohexane-1-carboxylate and (S)-3-isopropylpimelate, of anaerobic degradation of p-cymene in the bacterium Aromatoleum aromaticum pCyN1 are reported. These intermediates (as CoA esters) are involved in the further degradation of 4-isopropylbenzoyl-CoA formed by methyl group hydroxylation and subsequent oxidation of p-cymene. Proteogenomics indicated 4-isopropylbenzoyl-CoA degradation involves (i) a novel member of class I benzoyl-CoA reductase (BCR) as known from Thauera aromatica K172 and (ii) a modified $\beta$-oxidation pathway yielding 3-isopropylpimeloyl-CoA analogously to benzoyl-CoA degradation in Rhodopseudomonas palustris. Reference standards of all four diastereoisomers of 2-hydroxy-4-isopropylcyclohexane-1-carboxylate as well as both enantiomers of 3-isopropylpimelate were obtained by stereoselective syntheses via methyl 4-isopropyl-2-oxocyclohexane-1-carboxylate. The stereogenic center carrying the isopropyl group was established using a rhodium-catalyzed asymmetric conjugate addition. X-ray crystallography revealed that the thermodynamically most stable stereoisomer of 2-hydroxy-4-isopropylcyclohexane-1-carboxylate is formed during p-cymene degradation. Our findings imply that the reductive dearomatization of 4-isopropylbenzoyl-CoA by the BCR of A. aromaticum pCyN1 stereospecifically forms (S)-4-isopropyl-1,5-cyclohexadiene-1-carbonyl-CoA.},
      author = {K{\"{u}}ppers, Julian and Becker, Patrick and Jarling, Ren{\'{e}} and D{\"{o}}rries, Marvin and Caki{\'{c}},
      Nevenka and Schmidtmann, Marc and Christoffers, Jens and Rabus, Ralf and Wilkes, Heinz},
      doi = {10.1002/chem.201805837},
      file = {:C$\backslash$:/Users/Weiz/Nextcloud/GRK 2226/Publikationen/chem.201805837.pdf:pdf},
      issn = {0947-6539},
      journal = {Chemistry – A European Journal},
      keywords = {GRK2226,enzyme catalysis,natural products,proteomics,stereochemistry,structure elucidation},
      mendeley-tags = {GRK2226},
      month = {mar},
      number = {18},
      pages = {4722--4731},
      title = {{Stereochemical Insights into the Anaerobic Degradation of 4‐Isopropylbenzoyl‐CoA in the Denitrifying Bacterium Strain pCyN1}},
      url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/chem.201805837},
      volume = {25},
      year = {2019} }
  • J. Küppers, R. Rabus, H. Wilkes, and J. Christoffers, "Optically Active 1-Deuterio-1-phenylethane - Preparation and Proof of Enantiopurity," European Journal of Organic Chemistry, vol. 2019, iss. 15, pp. 2629-2634, 2019.
    @article{Kuppers2019, abstract = {Enantiopure (S)-(1- 2 H)ethylbenzene was prepared in two steps from optically active (S)-1-phenylethanol via (R)-(1-chloroethyl)benzene (two inversions of configuration). Since the value for the specific rotation [$\alpha$] is very low for the enantiomers of (1- 2 H)ethylbenzene, the enantiopurity of the synthetic product could not be determined with certainty by polarimetry. Therefore, bis-sulfonamides were prepared by twofold chlorosulfonation (para and ortho) of (S)-(1- 2 H)ethylbenzene and subsequent amidation with (R)- and (S)-$\alpha$-phenethylamine. For both diastereoisomers, the (R,R,S)- and the (S,S,S)-sulfonamides, 92 {\%} de was determined by 1 H NMR spectroscopy. Therefore, it could be concluded, that (S)-(1- 2 H)ethylbenzene had been obtained with 92 {\%} ee.},
      author = {K{\"{u}}ppers, Julian and Rabus, Ralf and Wilkes, Heinz and Christoffers, Jens},
      doi = {10.1002/ejoc.201900121},
      file = {:C$\backslash$:/Users/Weiz/Nextcloud/GRK 2226/Publikationen/ejoc.201900121.pdf:pdf},
      issn = {1434193X},
      journal = {European Journal of Organic Chemistry},
      keywords = {Chirality,Deuteration,GRK2226,Hydrocarbons,Sulfonamides},
      mendeley-tags = {GRK2226},
      month = {apr},
      number = {15},
      pages = {2629--2634},
      title = {{Optically Active 1-Deuterio-1-phenylethane - Preparation and Proof of Enantiopurity}},
      url = {http://doi.wiley.com/10.1002/ejoc.201900121},
      volume = {2019},
      year = {2019} }
  • A. Markovic, L. Buschbeck, T. Klüner, J. Christoffers, and G. Wittstock, "Electron Transfer and Electron Excitation Processes in 2,5‐Diaminoterephthalate Derivatives with Broad Scope for Functionalization," ChemistryOpen, vol. 8, iss. 9, pp. 1176-1182, 2019.
    @article{Markovic2019, abstract = {Derivatives of 2,5-diaminoterephthalate (DAT) are efficient fluorescence dyes that are also redox-active, thus allowing for the electrochemical manipulation of spectral properties. The electrochemical behaviour of seven DAT derivatives was studied by cyclic voltammetry in dichloromethane. In the absence of a proton donor, DATs should be oxidized in two one-electron steps. The first step is usually quasi-reversible while the second step is either quasi-reversible or irreversible. Some electrochemical properties such as the formal potentials and the ratio between the anodic and the cathodic current were determined from the cyclic voltammograms. Correlation between the formal potential of first oxidation and the absorption or the fluorescence emission wavelengths are established for this specific type of dyes. These correlations were confirmed with density functional theory calculations.},
      author = {Markovic, Aleksandra and Buschbeck, Leon and Kl{\"{u}}ner, Thorsten and Christoffers, Jens and Wittstock, Gunther},
      doi = {10.1002/open.201900138},
      file = {:C$\backslash$:/Users/Weiz/Nextcloud/GRK 2226/Publikationen/open.201900138.pdf:pdf},
      issn = {2191-1363},
      journal = {ChemistryOpen},
      keywords = {Diaminoterephthalates,GRK2226,UV/vis spectroscopy,fluorescence dyes,fluorescence spectroscopy,molecular electrochemistry},
      mendeley-tags = {GRK2226},
      month = {sep},
      number = {9},
      pages = {1176--1182},
      title = {{Electron Transfer and Electron Excitation Processes in 2,5‐Diaminoterephthalate Derivatives with Broad Scope for Functionalization}},
      url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/open.201900138},
      volume = {8},
      year = {2019} }
  • [article] bibtex
    L. Mohrhusen, M. Grebien, and K. Al-Shamery, "Defect dependent adsorption of organic molecules on tungsten oxide clusters on rutile TiO2," Bunsen Magazin, vol. 21, iss. 5, p. 202, 2019.
    @article{Mohrhusen2019a,
      author = {Mohrhusen, Lars and Grebien, M. and Al-Shamery, Katharina},
      journal = {Bunsen Magazin},
      keywords = {?},
      mendeley-tags = {?},
      number = {5},
      pages = {202},
      title = {{Defect dependent adsorption of organic molecules on tungsten oxide clusters on rutile TiO2}},
      volume = {21},
      year = {2019} }
  • L. Mohrhusen, J. Kräuter, M. Willms, and K. Al-Shamery, "Argon Embedded by Ion Bombardment: Relevance of Hidden Dopants in Rutile TiO 2," The Journal of Physical Chemistry C, vol. 123, iss. 33, pp. 20434-20442, 2019.
    @article{Mohrhusen2019, abstract = {To obtain a mechanistic understanding of occurring processes on oxide surfaces at the atomic level, systematic studies under ultra-high vacuum (UHV) conditions on single crystalline surfaces are commonly used. Usually, the sample preparation protocol for these surfaces includes argon-ion bombardment followed by annealing at elevated temperatures. For reduceable metal oxides, this leads to a significant reduction of the surface. Up to now, the particular role of the remaining argon in the subsequent formation of clean surfaces and the possible incorporation of argon into the crystal lattice as a dopant are typically neglected or remain unclear. This work presents combined, temperature-dependent X-ray photoelectron spectroscopy and a low-energy electron diffraction study under UHV conditions of the bulk-assisted reoxidation and restructuring of the rutile TiO2(110) single crystal surface after argon-ion bombardment. The formation of an ordered and reoxidized (110)(1 × 1) surface is accompanied by a stepwise desorption of argon from the sample. Moreover, we present a systematic study of the incorporation of argon in the rutile crystal as well as the diffusion and desorption of argon from these samples. By following the temperature-dependent Ar 2p photoelectron spectra, the change of the electronic environment of embedded argon is elucidated, demonstrating the interaction with reduced Ti cations. Hence, residual argon (in case of Ar+) possibly acts as a strong oxidant or induces significant lattice distortions. Our results show that residual argon from the sample preparation is an important hidden dopant and needs to be considered in the evaluation of typical studies on oxide surfaces under UHV conditions in future work.},
      author = {Mohrhusen, Lars and Kr{\"{a}}uter, Jessica and Willms, Michael and Al-Shamery, Katharina},
      doi = {10.1021/acs.jpcc.9b05975},
      file = {:C$\backslash$:/Users/Weiz/Nextcloud/GRK 2226/Publikationen/acs.jpcc.9b05975.pdf:pdf},
      issn = {1932-7447},
      journal = {The Journal of Physical Chemistry C},
      keywords = {GRK2226},
      mendeley-tags = {GRK2226},
      month = {aug},
      number = {33},
      pages = {20434--20442},
      title = {{Argon Embedded by Ion Bombardment: Relevance of Hidden Dopants in Rutile TiO 2}},
      url = {https://pubs.acs.org/doi/10.1021/acs.jpcc.9b05975},
      volume = {123},
      year = {2019} }
  • S. Neumann, J. Schröder, F. Bizzotto, M. Arenz, A. Dworzak, M. Oezaslan, M. Bäumer, and S. Kunz, "Halide‐Induced Leaching of Pt Nanoparticles – Manipulation of Particle Size by Controlled Ostwald Ripening," ChemNanoMat, vol. 5, iss. 4, pp. 462-471, 2019.
    @article{Neumann2019, abstract = {The synthesis of “surfactant-free” Pt nanoparticles (NPs) in alkaline ethylene glycol (EG), initially introduced in 2000, is of fundamental interest for the preparation of catalysts. Often a suspension of colloidal Pt NPs prepared by this method is stored and upon demand further processed to obtain supported catalysts such as Pt−C or Pt−Al 2 O 3 . In this study it is shown that in such colloidal suspensions in the presence of halides, e. g. from the metal precursor salt, leaching of Pt NPs takes place. Metal leaching poses a significant challenge for catalyst stability. However, if the reaction conditions are chosen appropriately, the here identified leaching process can be utilized to achieve particle growth by Ostwald ripening in a controlled manner. By changing the chemical nature of the metal precursor salt and variation of the reaction time, Pt NPs with a narrow size distribution between 1 to 4 nm are obtained without any need of surfactants. Subsequently, the obtained particles can be transferred into low-boiling organic solvents, which then allows for coating of deliberately chosen supports to prepare e. g. model catalyst which are tailored in terms of particle size and support material. The suitability of such materials for catalytic investigations is demonstrated by using CO oxidation as a model reaction and it is shown that the catalytic activity (surface normalized) depends on the size of Pt NPs under the applied reaction conditions.},
      author = {Neumann, Sarah and Schr{\"{o}}der, Johanna and Bizzotto, Francesco and Arenz, Matthias and Dworzak, Alexandra and Oezaslan, Mehtap and B{\"{a}}umer, Marcus and Kunz, Sebastian},
      doi = {10.1002/cnma.201800550},
      file = {:C$\backslash$:/Users/Weiz/Nextcloud/GRK 2226/Publikationen/cnma.201800550.pdf:pdf},
      issn = {2199-692X},
      journal = {ChemNanoMat},
      keywords = {?,CO oxidation,Ostwald ripening,metal leaching,particle size effect,size control,“surfactant-free” platinum nanoparticles},
      mendeley-tags = {?},
      month = {apr},
      number = {4},
      pages = {462--471},
      title = {{Halide‐Induced Leaching of Pt Nanoparticles – Manipulation of Particle Size by Controlled Ostwald Ripening}},
      url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/cnma.201800550},
      volume = {5},
      year = {2019} }
  • M. Osmić, L. Mohrhusen, and K. Al-Shamery, "Bulk Defect Dependence of Low-Temperature Partial Oxidation of Methanol and High-Temperature Hydrocarbon Formation on Rutile TiO 2 (110)," The Journal of Physical Chemistry C, vol. 123, iss. 13, pp. 7615-7626, 2019.
    @article{Osmic2019, abstract = {Titanium dioxide (TiO 2 ) is among the most studied model (photo)catalyst materials. The influence of surface point defects, like oxygen vacancies and particularly bulk defects such as Ti 3+ interstitials, is usually underestimated or even ignored. We present a systematic study under well-defined UHV conditions illustrating the importance of such defects for the thermal reaction of methanol at the rutile TiO 2 (110) single crystal surface by using temperature-programmed reaction spectroscopy (TPRS) and Fourier-transform infrared reflection-absorption spectroscopy (FT-IRRAS). It will be shown that the population of different reaction pathways, namely, the partial oxidation of methanol to formaldehyde and the deoxygenation forming hydrocarbons, especially methane, depends on the bulk defect density and the presence or absence of oxygen adsorbates. While at elevated temperatures molecular desorption is pronounced for the less defective substrates, for higher reduction grades the high-temperature deoxygenation channel via methoxy intermediates is favored. In addition, preadsorption of oxygen enables low- and high-temperature partial oxidation forming formaldehyde, likely from a dioxomethylene-like adsorbate.},
      author = {Osmi{\'{c}},
      Milena and Mohrhusen, Lars and Al-Shamery, Katharina},
      doi = {10.1021/acs.jpcc.8b02953},
      file = {:C$\backslash$:/Users/Weiz/Nextcloud/GRK 2226/Publikationen/acs.jpcc.8b02953.pdf:pdf},
      issn = {1932-7447},
      journal = {The Journal of Physical Chemistry C},
      keywords = {GRK2226},
      mendeley-tags = {GRK2226},
      month = {apr},
      number = {13},
      pages = {7615--7626},
      title = {{Bulk Defect Dependence of Low-Temperature Partial Oxidation of Methanol and High-Temperature Hydrocarbon Formation on Rutile TiO 2 (110)}},
      url = {https://pubs.acs.org/doi/10.1021/acs.jpcc.8b02953},
      volume = {123},
      year = {2019} }

2018

  • H. Kollmann, M. Esmann, J. Witt, A. Markovic, V. Smirnov, G. Wittstock, M. Silies, and C. Lienau, "Fourier-transform spatial modulation spectroscopy of single gold nanorods," Nanophotonics, vol. 7, iss. 4, pp. 715-726, 2018.
    @article{Kollmann2018, abstract = {Sensing the scattered fields of single metallic nanostructures is a crucial step towards the applications of isolated plasmonic antennas, such as for the sensing of single molecules or nanoparticles. In the past, both near- and far-field spectroscopy methods have been applied to monitor single plasmonic resonances. So far, however, these spectral-domain techniques do not yet provide the femtosecond time resolution that is needed to probe the dynamics of plasmonic fields in the time domain. Here, we introduce a time-domain technique that combines broadband Fourier-transform spectroscopy and spatial modulation spectroscopy (FT-SMS) to quantitatively measure the extinction spectra of the isolated gold nanorods with a nominal footprint of 41×10 nm 2 . Using a phase-stable pulse pair for excitation, the technique is capable of rejecting off-resonant stray fields and providing absolute measurements of the extinction cross section. Our results indicate that the method is well suited for measuring the optical response of strongly coupled hybrid systems with high signal-to-noise ratio. It may form the basis for new approaches towards time-domain spectroscopy of single nanoantennas with few-cycle time resolution.},
      author = {Kollmann, Heiko and Esmann, Martin and Witt, Julia and Markovic, Aleksandra and Smirnov, Vladimir and Wittstock, Gunther and Silies, Martin and Lienau, Christoph},
      doi = {10.1515/nanoph-2017-0096},
      file = {:C$\backslash$:/Users/Weiz/Nextcloud/GRK 2226/Publikationen/[21928614 - Nanophotonics] Fourier-transform spatial modulation spectroscopy of single gold nanorods.pdf:pdf},
      issn = {2192-8614},
      journal = {Nanophotonics},
      keywords = {?,Fourier-transform spectroscopy,Spatial modulation spectroscopy,extinction cross section,field autocorrelation,gold nanorods,localized surface plasmon resonance},
      mendeley-tags = {?},
      month = {mar},
      number = {4},
      pages = {715--726},
      title = {{Fourier-transform spatial modulation spectroscopy of single gold nanorods}},
      url = {https://www.degruyter.com/view/journals/nanoph/7/4/article-p715.xml},
      volume = {7},
      year = {2018} }
  • P. Sander, A. Markovic, M. Schmidtmann, O. Janka, G. Wittstock, and R. Beckhaus, "Synthesis, Crystal Structures, and Magnetic and Electrochemical Properties of Highly Phenyl Substituted Trinuclear 5,6,11,12,17,18-Hexaazatrinaphthylene (HATNPh 6 )-Bridged Titanium Complexes," Inorganic Chemistry, vol. 57, iss. 17, pp. 11165-11174, 2018.
    @article{Sander2018, abstract = {Trinuclear titanium complexes coordinated by one ligand with three coordination sites have shown properties of mixed valency and a high number of reversible redox steps. Herein we report on the hexaphenyl-substituted derivative (Cp2Ti)3($\mu$3-HATNPh6) (2). On reaction of 2 with the ferrocenium salt [Cp2Fe]BF4, the cationic complexes [(Cp2Ti)3($\mu$3-HATNPh6)]n+ (n = 1-3; 3-5) become available in a selective way. Cyclic voltammograms show 10 reversible redox states of the trinuclear species 2 without decomposition. In order to classify the degree of electronic communication between the titanium centers, comproportionation constants Kc, IVCT bands in NIR spectra, and magnetic measurements were analyzed. These parameters show strong coupling effects between the titanium centers but no full delocalization. In addition, single-crystal X-ray analysis of the neutral complex 2 and its oxidation products (1+ (3), 2+ (4), and 3+ (5)) revealed the geometric structure of the molecule in the solid state. For the cationic species anion-$\pi$ interactions between the electron-deficient central ring of the HATNPh6 ligand and BF4- counterions were found.},
      author = {Sander, Pia and Markovic, Aleksandra and Schmidtmann, Marc and Janka, Oliver and Wittstock, Gunther and Beckhaus, R{\"{u}}diger},
      doi = {10.1021/acs.inorgchem.8b01728},
      file = {:C$\backslash$:/Users/Weiz/Nextcloud/GRK 2226/Publikationen/acs.inorgchem.8b01728.pdf:pdf},
      issn = {0020-1669},
      journal = {Inorganic Chemistry},
      keywords = {?},
      mendeley-tags = {?},
      month = {sep},
      number = {17},
      pages = {11165--11174},
      pmid = {30095256},
      title = {{Synthesis, Crystal Structures, and Magnetic and Electrochemical Properties of Highly Phenyl Substituted Trinuclear 5,6,11,12,17,18-Hexaazatrinaphthylene (HATNPh 6 )-Bridged Titanium Complexes}},
      url = {https://pubs.acs.org/doi/10.1021/acs.inorgchem.8b01728},
      volume = {57},
      year = {2018} }
  • A. Kohlsdorf, D. H. Taffa, and M. Wark, "Microwave assisted synthesis of Ta2O5 nanostructures for photocatalytic hydrogen production," Journal of Photochemistry and Photobiology A: Chemistry, vol. 366, pp. 41-47, 2018.
    @article{Kohlsdorf2018,
      author = {Kohlsdorf, Arno and Taffa, Dereje Hailu and Wark, Michael},
      doi = {10.1016/j.jphotochem.2018.03.036},
      issn = {10106030},
      journal = {Journal of Photochemistry and Photobiology A: Chemistry},
      month = {nov},
      pages = {41--47},
      title = {{Microwave assisted synthesis of Ta2O5 nanostructures for photocatalytic hydrogen production}},
      url = {https://linkinghub.elsevier.com/retrieve/pii/S1010603017317173},
      volume = {366},
      year = {2018} }
  • L. Stelter, T. Teusch, J. Bielefeld, S. Doye, and T. Klüner, "Theoretical Studies on the Hydroaminoalkylation of Alkenes with Primary and Secondary Amines," Chemistry - A European Journal, vol. 24, iss. 48, pp. 12485-12489, 2018.
    @article{Stelter2018, abstract = {The $\alpha$-alkylation of amines with alkenes catalyzed by early transition-metal complexes represents an efficient and atom economic method for the synthesis of functionalized amines from simple and easily available starting materials. While the successful use of secondary amines, such as dimethylamine, strongly underlines the enormous industrial potential of this reaction, the analogous intermolecular $\alpha$-alkylation of primary amines, especially methylamine, remains an unsolved synthetic task to this day. Based on calculated thermodynamic data, these experimental findings can now be explained for the first time, whereby several competing reactions, which are explained in detail, are of crucial importance for the different behavior of primary and secondary amines.},
      author = {Stelter, Luisa and Teusch, Thomas and Bielefeld, Jens and Doye, Sven and Kl{\"{u}}ner, Thorsten},
      doi = {10.1002/chem.201802699},
      file = {:C$\backslash$:/Users/Weiz/Nextcloud/GRK 2226/Publikationen/chem.201802699.pdf:pdf},
      issn = {09476539},
      journal = {Chemistry - A European Journal},
      keywords = {C−H activation,DFT calculations,GRK2226,amines,homogeneous catalysis,titanium},
      mendeley-tags = {GRK2226},
      month = {aug},
      number = {48},
      pages = {12485--12489},
      pmid = {29917278},
      title = {{Theoretical Studies on the Hydroaminoalkylation of Alkenes with Primary and Secondary Amines}},
      url = {http://doi.wiley.com/10.1002/chem.201802699},
      volume = {24},
      year = {2018} }
  • M. Siemer, L. Mohrhusen, M. Grebien, and K. Al-Shamery, "Amine Capped Gold Colloids at Oxidic Supports: Their Electronic Interactions," Zeitschrift für Physikalische Chemie, vol. 233, iss. 1, pp. 69-84, 2018.
    @article{Siemer2018, abstract = {Colloidal deposition of noble metal nanoparticles on oxidic supports is a recent approach for the fabrication of heterogeneous catalyst materials. We present studies on the interaction of different amine ligands with gold nanoparticles before and after deposition on several oxidic supports (titania, silica, alumina, magnesia or zinc oxide), using X-ray photoelectron and Auger spectroscopy, and high-resolution transmission electron microscopy. The adsorption of amines on thin gold films as well as on nanoparticles leads to a decrease in metal photoelectron binding energies. Usually, this is explained by donor-acceptor interactions via the amine group. By additional analysis of Auger signals, which are more sensitive to changes in the oxidation state than photoelectron spectra, we demonstrate that these shifts are due to a final state effect, namely, the increased photoelectron hole screening in presence of amine adsorbates. It will be shown, that this effect is not sensitive neither to the nanoparticle size nor the sterical properties of the capping amine. After deposition on oxide supports, the photoelectron binding energies are even further decreased. The presented findings exhibit that care has to be taken to interpret binding energy shifts simply with charging, which has impact on understanding the local electronic situation on the surface of metal-loaded oxides, crucial for heterogeneous catalysis.},
      author = {Siemer, Michael and Mohrhusen, Lars and Grebien, Maximilian and Al-Shamery, Katharina},
      doi = {10.1515/zpch-2018-0004},
      file = {:C$\backslash$:/Users/Weiz/Nextcloud/GRK 2226/Publikationen/siemer2018.pdf:pdf},
      issn = {2196-7156},
      journal = {Zeitschrift f{\"{u}}r Physikalische Chemie},
      keywords = {?},
      mendeley-tags = {?},
      month = {dec},
      number = {1},
      pages = {69--84},
      title = {{Amine Capped Gold Colloids at Oxidic Supports: Their Electronic Interactions}},
      url = {http://www.degruyter.com/view/j/zpch.2019.233.issue-1/zpch-2018-0004/zpch-2018-0004.xml},
      volume = {233},
      year = {2018} }
(Changed: 2021-01-05)