---
_id: '63974'
abstract:
- lang: eng
  text: A versatile strategy for synthesizing tailored peptide based biradicals is
    presented. By labeling the protected amino acid hydroxyproline with PROXYL via
    the OH functionality and using this building block in solid phase peptide synthesis
    (SPPS), the obtained peptides become polarization agents for DNP enhanced solid-state
    NMR in biotolerant media. To analyze the effect of the radical position on the
    enhancement factor, three different biradicals are synthesized. The PROXYL spin-label
    is inserted in a collagen inspired artificial peptide sequence by binding through
    the OH group of the hydroxyproline moieties at specific position in the chain.
    This labeling strategy is universally applicable for any hydroxyproline position
    in a peptide sequence since solid-phase peptide synthesis is used to insert the
    building block. High performance liquid chromatography (HPLC) and mass spectrometry
    (MS) analyses show the successful introduction of the spin label in the peptide
    chain and electron paramagnetic resonance (EPR) spectroscopy confirms its activity.
    Dynamic nuclear polarization (DNP) enhanced solid-state nuclear magnetic resonance
    (NMR) experiments performed on frozen aqueous glycerol-d8 solutions containing
    these peptide radicals show significantly higher enhancement factors of up to
    45 in 1H→13C cross polarization magic angle spinning (CP MAS) experiments compared
    to an analogous mono-radical peptide including this building block (ε ≈ 14). Compared
    to commercial biradicals such as AMUPol for which enhancement factors {\textgreater}
    100 have been obtained in the past and which have been optimized in their structure,
    the obtained enhancement up to 45 for our biradicals presents a significant progress
    in radical design.
author:
- first_name: Kevin
  full_name: Herr, Kevin
  last_name: Herr
- first_name: Mark V.
  full_name: Höfler, Mark V.
  last_name: Höfler
- first_name: Henrike
  full_name: Heise, Henrike
  last_name: Heise
- first_name: Fabien
  full_name: Aussenac, Fabien
  last_name: Aussenac
- first_name: Felix
  full_name: Kornemann, Felix
  last_name: Kornemann
- first_name: David
  full_name: Rosenberger, David
  last_name: Rosenberger
- first_name: Martin
  full_name: Brodrecht, Martin
  last_name: Brodrecht
- first_name: Marcos
  full_name: Oliveira, Marcos
  last_name: Oliveira
- first_name: Gerd
  full_name: Buntkowsky, Gerd
  last_name: Buntkowsky
- first_name: Torsten
  full_name: Gutmann, Torsten
  id: '118165'
  last_name: Gutmann
citation:
  ama: Herr K, Höfler MV, Heise H, et al. Biradicals based on PROXYL containing building
    blocks for efficient dynamic nuclear polarization in biotolerant media. <i>Journal
    of Magnetic Resonance Open</i>. 2024;20:100152. doi:<a href="https://doi.org/10.1016/j.jmro.2024.100152">10.1016/j.jmro.2024.100152</a>
  apa: Herr, K., Höfler, M. V., Heise, H., Aussenac, F., Kornemann, F., Rosenberger,
    D., Brodrecht, M., Oliveira, M., Buntkowsky, G., &#38; Gutmann, T. (2024). Biradicals
    based on PROXYL containing building blocks for efficient dynamic nuclear polarization
    in biotolerant media. <i>Journal of Magnetic Resonance Open</i>, <i>20</i>, 100152.
    <a href="https://doi.org/10.1016/j.jmro.2024.100152">https://doi.org/10.1016/j.jmro.2024.100152</a>
  bibtex: '@article{Herr_Höfler_Heise_Aussenac_Kornemann_Rosenberger_Brodrecht_Oliveira_Buntkowsky_Gutmann_2024,
    title={Biradicals based on PROXYL containing building blocks for efficient dynamic
    nuclear polarization in biotolerant media}, volume={20}, DOI={<a href="https://doi.org/10.1016/j.jmro.2024.100152">10.1016/j.jmro.2024.100152</a>},
    journal={Journal of Magnetic Resonance Open}, author={Herr, Kevin and Höfler,
    Mark V. and Heise, Henrike and Aussenac, Fabien and Kornemann, Felix and Rosenberger,
    David and Brodrecht, Martin and Oliveira, Marcos and Buntkowsky, Gerd and Gutmann,
    Torsten}, year={2024}, pages={100152} }'
  chicago: 'Herr, Kevin, Mark V. Höfler, Henrike Heise, Fabien Aussenac, Felix Kornemann,
    David Rosenberger, Martin Brodrecht, Marcos Oliveira, Gerd Buntkowsky, and Torsten
    Gutmann. “Biradicals Based on PROXYL Containing Building Blocks for Efficient
    Dynamic Nuclear Polarization in Biotolerant Media.” <i>Journal of Magnetic Resonance
    Open</i> 20 (2024): 100152. <a href="https://doi.org/10.1016/j.jmro.2024.100152">https://doi.org/10.1016/j.jmro.2024.100152</a>.'
  ieee: 'K. Herr <i>et al.</i>, “Biradicals based on PROXYL containing building blocks
    for efficient dynamic nuclear polarization in biotolerant media,” <i>Journal of
    Magnetic Resonance Open</i>, vol. 20, p. 100152, 2024, doi: <a href="https://doi.org/10.1016/j.jmro.2024.100152">10.1016/j.jmro.2024.100152</a>.'
  mla: Herr, Kevin, et al. “Biradicals Based on PROXYL Containing Building Blocks
    for Efficient Dynamic Nuclear Polarization in Biotolerant Media.” <i>Journal of
    Magnetic Resonance Open</i>, vol. 20, 2024, p. 100152, doi:<a href="https://doi.org/10.1016/j.jmro.2024.100152">10.1016/j.jmro.2024.100152</a>.
  short: K. Herr, M.V. Höfler, H. Heise, F. Aussenac, F. Kornemann, D. Rosenberger,
    M. Brodrecht, M. Oliveira, G. Buntkowsky, T. Gutmann, Journal of Magnetic Resonance
    Open 20 (2024) 100152.
date_created: 2026-02-07T15:42:00Z
date_updated: 2026-02-17T16:17:22Z
doi: 10.1016/j.jmro.2024.100152
extern: '1'
intvolume: '        20'
keyword:
- solid-state nmr
- dynamic nuclear polarization
- peptides
- Biradicals
- Spin labeling
language:
- iso: eng
page: '100152'
publication: Journal of Magnetic Resonance Open
status: public
title: Biradicals based on PROXYL containing building blocks for efficient dynamic
  nuclear polarization in biotolerant media
type: journal_article
user_id: '100715'
volume: 20
year: '2024'
...
---
_id: '63975'
abstract:
- lang: eng
  text: In this contribution, we report on the TEMPO-mediated oxidation of pulp fibers
    used in the general context of papermaking and for the future design of tailor-made
    paper in advanced applications. We focus in our studies on properties of TEMPO-oxidized
    pulp fibers to explain the characteristics of the paper made thereof. 13C solid-state
    NMR analysis reveals that in particular amorphous regions of the fibers are being
    chemically oxidized, while at the same time the crystalline regions of the fibers
    are not significantly affected. Investigation of the fiber morphology before and
    after oxidation shows that the fiber length is not changed, yet the fibers do
    exhibit an increase in width if in contact with water, which is attributed to
    an increase in fiber swelling. In addition, fibrillation decreases due to the
    oxidative removal of loosely bound fines and fibrils, rendering the surface of
    the resulting oxidized fibers much smoother in comparison to the original fibers.
    Finally, we observe that both, dry and wet tensile strengths are also higher for
    paper made of oxidized fibers, most likely due to cross linkable aldehyde groups
    formed during oxidation (i.e. hemiacetal bond formation in the sheet during thermal
    drying). Our results of the oxidation of paper fibers thus offer a systematic
    study helpful for the design of tailor-made paper useful in several applications
    where a fiber-modification with fiber-immobilized functional motifs is crucial,
    such as for example in paper-based microfluidic sensors (µPADs) or lab-on a chip-devices.
author:
- first_name: Laura M.
  full_name: Hillscher, Laura M.
  last_name: Hillscher
- first_name: Mark V.
  full_name: Höfler, Mark V.
  last_name: Höfler
- first_name: Torsten
  full_name: Gutmann, Torsten
  id: '118165'
  last_name: Gutmann
- first_name: Cassia
  full_name: Lux, Cassia
  last_name: Lux
- first_name: K. Uta
  full_name: Clerkin, K. Uta
  last_name: Clerkin
- first_name: Gerhard
  full_name: Schwall, Gerhard
  last_name: Schwall
- first_name: Klaus
  full_name: Villforth, Klaus
  last_name: Villforth
- first_name: Samuel
  full_name: Schabel, Samuel
  last_name: Schabel
- first_name: Markus
  full_name: Biesalski, Markus
  last_name: Biesalski
citation:
  ama: Hillscher LM, Höfler MV, Gutmann T, et al. Influence of TEMPO-oxidation on
    pulp fiber chemistry, morphology and mechanical paper sheet properties. <i>Cellulose</i>.
    2024;31(5):3067–3082. doi:<a href="https://doi.org/10.1007/s10570-024-05748-5">10.1007/s10570-024-05748-5</a>
  apa: Hillscher, L. M., Höfler, M. V., Gutmann, T., Lux, C., Clerkin, K. U., Schwall,
    G., Villforth, K., Schabel, S., &#38; Biesalski, M. (2024). Influence of TEMPO-oxidation
    on pulp fiber chemistry, morphology and mechanical paper sheet properties. <i>Cellulose</i>,
    <i>31</i>(5), 3067–3082. <a href="https://doi.org/10.1007/s10570-024-05748-5">https://doi.org/10.1007/s10570-024-05748-5</a>
  bibtex: '@article{Hillscher_Höfler_Gutmann_Lux_Clerkin_Schwall_Villforth_Schabel_Biesalski_2024,
    title={Influence of TEMPO-oxidation on pulp fiber chemistry, morphology and mechanical
    paper sheet properties}, volume={31}, DOI={<a href="https://doi.org/10.1007/s10570-024-05748-5">10.1007/s10570-024-05748-5</a>},
    number={5}, journal={Cellulose}, author={Hillscher, Laura M. and Höfler, Mark
    V. and Gutmann, Torsten and Lux, Cassia and Clerkin, K. Uta and Schwall, Gerhard
    and Villforth, Klaus and Schabel, Samuel and Biesalski, Markus}, year={2024},
    pages={3067–3082} }'
  chicago: 'Hillscher, Laura M., Mark V. Höfler, Torsten Gutmann, Cassia Lux, K. Uta
    Clerkin, Gerhard Schwall, Klaus Villforth, Samuel Schabel, and Markus Biesalski.
    “Influence of TEMPO-Oxidation on Pulp Fiber Chemistry, Morphology and Mechanical
    Paper Sheet Properties.” <i>Cellulose</i> 31, no. 5 (2024): 3067–3082. <a href="https://doi.org/10.1007/s10570-024-05748-5">https://doi.org/10.1007/s10570-024-05748-5</a>.'
  ieee: 'L. M. Hillscher <i>et al.</i>, “Influence of TEMPO-oxidation on pulp fiber
    chemistry, morphology and mechanical paper sheet properties,” <i>Cellulose</i>,
    vol. 31, no. 5, pp. 3067–3082, 2024, doi: <a href="https://doi.org/10.1007/s10570-024-05748-5">10.1007/s10570-024-05748-5</a>.'
  mla: Hillscher, Laura M., et al. “Influence of TEMPO-Oxidation on Pulp Fiber Chemistry,
    Morphology and Mechanical Paper Sheet Properties.” <i>Cellulose</i>, vol. 31,
    no. 5, 2024, pp. 3067–3082, doi:<a href="https://doi.org/10.1007/s10570-024-05748-5">10.1007/s10570-024-05748-5</a>.
  short: L.M. Hillscher, M.V. Höfler, T. Gutmann, C. Lux, K.U. Clerkin, G. Schwall,
    K. Villforth, S. Schabel, M. Biesalski, Cellulose 31 (2024) 3067–3082.
date_created: 2026-02-07T15:42:23Z
date_updated: 2026-02-17T16:17:19Z
doi: 10.1007/s10570-024-05748-5
extern: '1'
intvolume: '        31'
issue: '5'
language:
- iso: eng
page: 3067–3082
publication: Cellulose
publication_identifier:
  issn:
  - 0969-0239
status: public
title: Influence of TEMPO-oxidation on pulp fiber chemistry, morphology and mechanical
  paper sheet properties
type: journal_article
user_id: '100715'
volume: 31
year: '2024'
...
---
_id: '63970'
abstract:
- lang: eng
  text: Abstract Recent advances in solid-state nuclear magnetic resonance (NMR) spectroscopy,
    combined with dynamic nuclear polarization (DNP), quantum chemical DFT calculations,
    and gas-phase NMR spectroscopy investigating the structure and reactivity of heterogeneous
    catalysts are reviewed. The investigated catalysts range from classical mononuclear
    catalysts, like immobilized derivates of Wilkinson’s catalysts over binuclear
    catalysts such as the dirhodium paddlewheel catalyst to catalytic nanoparticles,
    employing various support materials, such as mesoporous silica gels, coordination
    polymers, and biomaterials such as cellulose.
author:
- first_name: Nadia
  full_name: Haro Mares, Nadia
  last_name: Haro Mares
- first_name: Millena
  full_name: Logrado, Millena
  last_name: Logrado
- first_name: Jan
  full_name: Kergassner, Jan
  last_name: Kergassner
- first_name: Bingyu
  full_name: Zhang, Bingyu
  last_name: Zhang
- first_name: Torsten
  full_name: Gutmann, Torsten
  id: '118165'
  last_name: Gutmann
- first_name: Gerd
  full_name: Buntkowsky, Gerd
  last_name: Buntkowsky
citation:
  ama: Haro Mares N, Logrado M, Kergassner J, Zhang B, Gutmann T, Buntkowsky G. Solid-State
    NMR of Heterogeneous Catalysts. <i>ChemCatChem</i>. Published online 2024:e202401159.
    doi:<a href="https://doi.org/10.1002/cctc.202401159">10.1002/cctc.202401159</a>
  apa: Haro Mares, N., Logrado, M., Kergassner, J., Zhang, B., Gutmann, T., &#38;
    Buntkowsky, G. (2024). Solid-State NMR of Heterogeneous Catalysts. <i>ChemCatChem</i>,
    e202401159. <a href="https://doi.org/10.1002/cctc.202401159">https://doi.org/10.1002/cctc.202401159</a>
  bibtex: '@article{Haro Mares_Logrado_Kergassner_Zhang_Gutmann_Buntkowsky_2024, title={Solid-State
    NMR of Heterogeneous Catalysts}, DOI={<a href="https://doi.org/10.1002/cctc.202401159">10.1002/cctc.202401159</a>},
    journal={ChemCatChem}, publisher={John Wiley &#38; Sons, Ltd}, author={Haro Mares,
    Nadia and Logrado, Millena and Kergassner, Jan and Zhang, Bingyu and Gutmann,
    Torsten and Buntkowsky, Gerd}, year={2024}, pages={e202401159} }'
  chicago: Haro Mares, Nadia, Millena Logrado, Jan Kergassner, Bingyu Zhang, Torsten
    Gutmann, and Gerd Buntkowsky. “Solid-State NMR of Heterogeneous Catalysts.” <i>ChemCatChem</i>,
    2024, e202401159. <a href="https://doi.org/10.1002/cctc.202401159">https://doi.org/10.1002/cctc.202401159</a>.
  ieee: 'N. Haro Mares, M. Logrado, J. Kergassner, B. Zhang, T. Gutmann, and G. Buntkowsky,
    “Solid-State NMR of Heterogeneous Catalysts,” <i>ChemCatChem</i>, p. e202401159,
    2024, doi: <a href="https://doi.org/10.1002/cctc.202401159">10.1002/cctc.202401159</a>.'
  mla: Haro Mares, Nadia, et al. “Solid-State NMR of Heterogeneous Catalysts.” <i>ChemCatChem</i>,
    John Wiley &#38; Sons, Ltd, 2024, p. e202401159, doi:<a href="https://doi.org/10.1002/cctc.202401159">10.1002/cctc.202401159</a>.
  short: N. Haro Mares, M. Logrado, J. Kergassner, B. Zhang, T. Gutmann, G. Buntkowsky,
    ChemCatChem (2024) e202401159.
date_created: 2026-02-07T15:40:38Z
date_updated: 2026-02-17T16:17:30Z
doi: 10.1002/cctc.202401159
extern: '1'
keyword:
- solid-state nmr
- heterogeneous catalysis
- dynamic nuclear polarization
- Nanocatalysis
- Surface-reactions
language:
- iso: eng
page: e202401159
publication: ChemCatChem
publication_identifier:
  issn:
  - 1867-3880
publisher: John Wiley & Sons, Ltd
status: public
title: Solid-State NMR of Heterogeneous Catalysts
type: journal_article
user_id: '100715'
year: '2024'
...
---
_id: '64045'
abstract:
- lang: eng
  text: Abstract In this work, we report on an improved cell assembly of cylindrical
    electrochemical cells for 23Na in-situ solid-state NMR (ssNMR) investigations.
    The cell set-up is suitable for using powder electrode materials. Reproducibility
    of our cell assembly is analyzed by preparing two cells containing hard carbon
    (HC) powder as working electrode and sodium metal as reference electrode. Electrochemical
    storage properties of HC powder electrode derived from carbonization of sustainable
    cellulose are studied by ssNMR. 23Na in-situ ssNMR monitors the sodiation/desodiation
    of a Na{\textbar}NaPF6{\textbar}HC cell (cell 1) over a period of 22?days, showing
    high cell stability. After the galvanostatic process, the HC powder material is
    investigated by high resolution 23Na ex-situ MAS NMR. The formation of ionic sodium
    species in different chemical environments is obtained. Subsequently, a second
    Na{\textbar}NaPF6{\textbar}HC cell (cell 2) is sodiated for 11?days achieving
    a capacity of 220?mAh/g. 23Na ex-situ MAS NMR measurements of the HC powder material
    extracted from this cell clearly indicate the presence of quasi-metallic sodium
    species next to ionic sodium species. This observation of quasi-metallic sodium
    species is discussed in terms of the achieved capacity of the cell as well as
    of side reactions of sodium in this electrode material.
author:
- first_name: Edina
  full_name: Šić, Edina
  last_name: Šić
- first_name: Konstantin
  full_name: Schutjajew, Konstantin
  last_name: Schutjajew
- first_name: Ulrich
  full_name: Haagen, Ulrich
  last_name: Haagen
- first_name: Hergen
  full_name: Breitzke, Hergen
  last_name: Breitzke
- first_name: Martin
  full_name: Oschatz, Martin
  last_name: Oschatz
- first_name: Gerd
  full_name: Buntkowsky, Gerd
  last_name: Buntkowsky
- first_name: Torsten
  full_name: Gutmann, Torsten
  id: '118165'
  last_name: Gutmann
citation:
  ama: 'Šić E, Schutjajew K, Haagen U, et al. Electrochemical Sodium Storage in Hard
    Carbon Powder Electrodes Implemented in an Improved Cell Assembly: Insights from
    In-Situ and Ex-Situ Solid-State NMR. <i>Chemsuschem</i>. 2023;17:e202301300. doi:<a
    href="https://doi.org/10.1002/cssc.202301300">10.1002/cssc.202301300</a>'
  apa: 'Šić, E., Schutjajew, K., Haagen, U., Breitzke, H., Oschatz, M., Buntkowsky,
    G., &#38; Gutmann, T. (2023). Electrochemical Sodium Storage in Hard Carbon Powder
    Electrodes Implemented in an Improved Cell Assembly: Insights from In-Situ and
    Ex-Situ Solid-State NMR. <i>Chemsuschem</i>, <i>17</i>, e202301300. <a href="https://doi.org/10.1002/cssc.202301300">https://doi.org/10.1002/cssc.202301300</a>'
  bibtex: '@article{Šić_Schutjajew_Haagen_Breitzke_Oschatz_Buntkowsky_Gutmann_2023,
    title={Electrochemical Sodium Storage in Hard Carbon Powder Electrodes Implemented
    in an Improved Cell Assembly: Insights from In-Situ and Ex-Situ Solid-State NMR},
    volume={17}, DOI={<a href="https://doi.org/10.1002/cssc.202301300">10.1002/cssc.202301300</a>},
    journal={Chemsuschem}, publisher={John Wiley &#38; Sons, Ltd}, author={Šić, Edina
    and Schutjajew, Konstantin and Haagen, Ulrich and Breitzke, Hergen and Oschatz,
    Martin and Buntkowsky, Gerd and Gutmann, Torsten}, year={2023}, pages={e202301300}
    }'
  chicago: 'Šić, Edina, Konstantin Schutjajew, Ulrich Haagen, Hergen Breitzke, Martin
    Oschatz, Gerd Buntkowsky, and Torsten Gutmann. “Electrochemical Sodium Storage
    in Hard Carbon Powder Electrodes Implemented in an Improved Cell Assembly: Insights
    from In-Situ and Ex-Situ Solid-State NMR.” <i>Chemsuschem</i> 17 (2023): e202301300.
    <a href="https://doi.org/10.1002/cssc.202301300">https://doi.org/10.1002/cssc.202301300</a>.'
  ieee: 'E. Šić <i>et al.</i>, “Electrochemical Sodium Storage in Hard Carbon Powder
    Electrodes Implemented in an Improved Cell Assembly: Insights from In-Situ and
    Ex-Situ Solid-State NMR,” <i>Chemsuschem</i>, vol. 17, p. e202301300, 2023, doi:
    <a href="https://doi.org/10.1002/cssc.202301300">10.1002/cssc.202301300</a>.'
  mla: 'Šić, Edina, et al. “Electrochemical Sodium Storage in Hard Carbon Powder Electrodes
    Implemented in an Improved Cell Assembly: Insights from In-Situ and Ex-Situ Solid-State
    NMR.” <i>Chemsuschem</i>, vol. 17, John Wiley &#38; Sons, Ltd, 2023, p. e202301300,
    doi:<a href="https://doi.org/10.1002/cssc.202301300">10.1002/cssc.202301300</a>.'
  short: E. Šić, K. Schutjajew, U. Haagen, H. Breitzke, M. Oschatz, G. Buntkowsky,
    T. Gutmann, Chemsuschem 17 (2023) e202301300.
date_created: 2026-02-07T16:12:13Z
date_updated: 2026-02-17T16:13:10Z
doi: 10.1002/cssc.202301300
extern: '1'
intvolume: '        17'
keyword:
- solid-state nmr
- hard carbon
- electrochemical cells
- in-situ characterization
- sodium
language:
- iso: eng
page: e202301300
publication: Chemsuschem
publication_identifier:
  issn:
  - 1864-5631
publisher: John Wiley & Sons, Ltd
status: public
title: 'Electrochemical Sodium Storage in Hard Carbon Powder Electrodes Implemented
  in an Improved Cell Assembly: Insights from In-Situ and Ex-Situ Solid-State NMR'
type: journal_article
user_id: '100715'
volume: 17
year: '2023'
...
---
_id: '64044'
abstract:
- lang: eng
  text: Abstract Polymer-derived silicon oxycarbide ceramics (SiCO) have been considered
    as potential anode materials for lithium- and sodium-ion batteries. To understand
    their electrochemical storage behavior, detailed insights into structural sites
    present in SiCO are required. In this work, the study of local structures in SiCO
    ceramics containing different amounts of carbon is presented. 13C and 29Si solid-state
    MAS?NMR spectroscopy combined with DFT calculations, atomistic modeling, and EPR
    investigations, suggest significant changes in the local structures of SiCO ceramics
    even by small changes in the material composition. The provided findings on SiCO
    structures will contribute to the research field of polymer-derived ceramics,
    especially to understand electrochemical storage processes of alkali metal/ions
    such as Na/Na+ inside such networks in the future.
author:
- first_name: Edina
  full_name: Šić, Edina
  last_name: Šić
- first_name: Jochen
  full_name: Rohrer, Jochen
  last_name: Rohrer
- first_name: Emmanuel
  full_name: Ricohermoso, Emmanuel
  last_name: Ricohermoso
- first_name: Karsten
  full_name: Albe, Karsten
  last_name: Albe
- first_name: Emmanuel
  full_name: Ionescu, Emmanuel
  last_name: Ionescu
- first_name: Ralf
  full_name: Riedel, Ralf
  last_name: Riedel
- first_name: Hergen
  full_name: Breitzke, Hergen
  last_name: Breitzke
- first_name: Torsten
  full_name: Gutmann, Torsten
  id: '118165'
  last_name: Gutmann
- first_name: Gerd
  full_name: Buntkowsky, Gerd
  last_name: Buntkowsky
citation:
  ama: 'Šić E, Rohrer J, Ricohermoso E, et al. SiCO Ceramics as Storage Materials
    for Alkali Metals/Ions: Insights on Structure Moieties from Solid-State NMR and
    DFT Calculations. <i>Chemsuschem</i>. 2023;16:e202202241. doi:<a href="https://doi.org/10.1002/cssc.202202241">10.1002/cssc.202202241</a>'
  apa: 'Šić, E., Rohrer, J., Ricohermoso, E., Albe, K., Ionescu, E., Riedel, R., Breitzke,
    H., Gutmann, T., &#38; Buntkowsky, G. (2023). SiCO Ceramics as Storage Materials
    for Alkali Metals/Ions: Insights on Structure Moieties from Solid-State NMR and
    DFT Calculations. <i>Chemsuschem</i>, <i>16</i>, e202202241. <a href="https://doi.org/10.1002/cssc.202202241">https://doi.org/10.1002/cssc.202202241</a>'
  bibtex: '@article{Šić_Rohrer_Ricohermoso_Albe_Ionescu_Riedel_Breitzke_Gutmann_Buntkowsky_2023,
    title={SiCO Ceramics as Storage Materials for Alkali Metals/Ions: Insights on
    Structure Moieties from Solid-State NMR and DFT Calculations}, volume={16}, DOI={<a
    href="https://doi.org/10.1002/cssc.202202241">10.1002/cssc.202202241</a>}, journal={Chemsuschem},
    publisher={John Wiley &#38; Sons, Ltd}, author={Šić, Edina and Rohrer, Jochen
    and Ricohermoso, Emmanuel and Albe, Karsten and Ionescu, Emmanuel and Riedel,
    Ralf and Breitzke, Hergen and Gutmann, Torsten and Buntkowsky, Gerd}, year={2023},
    pages={e202202241} }'
  chicago: 'Šić, Edina, Jochen Rohrer, Emmanuel Ricohermoso, Karsten Albe, Emmanuel
    Ionescu, Ralf Riedel, Hergen Breitzke, Torsten Gutmann, and Gerd Buntkowsky. “SiCO
    Ceramics as Storage Materials for Alkali Metals/Ions: Insights on Structure Moieties
    from Solid-State NMR and DFT Calculations.” <i>Chemsuschem</i> 16 (2023): e202202241.
    <a href="https://doi.org/10.1002/cssc.202202241">https://doi.org/10.1002/cssc.202202241</a>.'
  ieee: 'E. Šić <i>et al.</i>, “SiCO Ceramics as Storage Materials for Alkali Metals/Ions:
    Insights on Structure Moieties from Solid-State NMR and DFT Calculations,” <i>Chemsuschem</i>,
    vol. 16, p. e202202241, 2023, doi: <a href="https://doi.org/10.1002/cssc.202202241">10.1002/cssc.202202241</a>.'
  mla: 'Šić, Edina, et al. “SiCO Ceramics as Storage Materials for Alkali Metals/Ions:
    Insights on Structure Moieties from Solid-State NMR and DFT Calculations.” <i>Chemsuschem</i>,
    vol. 16, John Wiley &#38; Sons, Ltd, 2023, p. e202202241, doi:<a href="https://doi.org/10.1002/cssc.202202241">10.1002/cssc.202202241</a>.'
  short: E. Šić, J. Rohrer, E. Ricohermoso, K. Albe, E. Ionescu, R. Riedel, H. Breitzke,
    T. Gutmann, G. Buntkowsky, Chemsuschem 16 (2023) e202202241.
date_created: 2026-02-07T16:11:46Z
date_updated: 2026-02-17T16:13:11Z
doi: 10.1002/cssc.202202241
extern: '1'
intvolume: '        16'
keyword:
- NMR spectroscopy
- Ceramics
- defects
- density functional calculations
- EPR spectroscopy
language:
- iso: eng
page: e202202241
publication: Chemsuschem
publication_identifier:
  issn:
  - 1864-5631
publisher: John Wiley & Sons, Ltd
status: public
title: 'SiCO Ceramics as Storage Materials for Alkali Metals/Ions: Insights on Structure
  Moieties from Solid-State NMR and DFT Calculations'
type: journal_article
user_id: '100715'
volume: 16
year: '2023'
...
---
_id: '64040'
abstract:
- lang: eng
  text: The oxidative dehydrogenation (ODH) of propane is of great technical importance,
    and supported VOx catalysts have shown promising properties for the reaction.
    One of the most prominent and active supports is titania, which exhibits a high
    activity but many questions regarding the catalyst system are still in debate.
    In this study, we elucidate the mechanism of the propane ODH reaction over VOx/TiO2,
    using P25 and ALD (atomic layer deposition) synthesized TiO2/SBA-15 as a support,
    with X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), 51V solid-state
    (ss)NMR, operando multiwavelength Raman, operando UV–vis, and transient IR spectroscopies.
    Bare titania shows a small conversion, leading to carbon formation, and the reaction
    occurs at the interface between anatase and rutile. In comparison, in VOx/TiO2
    catalysts, the activity shifts from titania to vanadia sites. UV-Raman spectroscopy
    and structural characterization data revealed the reaction to involve preferentially
    the V═O bonds of dimeric species rather than doubly bridged V–O–V bonds, which
    leads to higher propene selectivities. The active vanadium site shows a nuclearity-dependent
    behavior; that is, at higher loadings, when oligomeric vanadia is present, it
    shifts from V═O bonds to linear V–O–V bonds in oligomers, leading to less selective
    oxidation due to the better reducibility. Our operando/transient spectroscopic
    results demonstrate the direct participation of the titania support in the reaction
    by influencing the degree of vanadia oligomerization and enabling rapid hydrogen
    transfer from propane to vanadia via Ti–OH groups on anatase, accelerating the
    rate-determining step of the initial C–H bond breakage. The broader applicability
    of the results is confirmed by the behavior of the ALD-synthesized sample, which
    resembles that of P25. Our results highlight the detailed level of mechanistic
    understanding accessible from multiple spectroscopic approaches, which can be
    readily transferred to other materials and/or reactions. The oxidative dehydrogenation
    (ODH) of propane is of great technical importance, and supported VOx catalysts
    have shown promising properties for the reaction. One of the most prominent and
    active supports is titania, which exhibits a high activity but many questions
    regarding the catalyst system are still in debate. In this study, we elucidate
    the mechanism of the propane ODH reaction over VOx/TiO2, using P25 and ALD (atomic
    layer deposition) synthesized TiO2/SBA-15 as a support, with X-ray photoelectron
    spectroscopy (XPS), X-ray diffraction (XRD), 51V solid-state (ss)NMR, operando
    multiwavelength Raman, operando UV–vis, and transient IR spectroscopies. Bare
    titania shows a small conversion, leading to carbon formation, and the reaction
    occurs at the interface between anatase and rutile. In comparison, in VOx/TiO2
    catalysts, the activity shifts from titania to vanadia sites. UV-Raman spectroscopy
    and structural characterization data revealed the reaction to involve preferentially
    the V═O bonds of dimeric species rather than doubly bridged V–O–V bonds, which
    leads to higher propene selectivities. The active vanadium site shows a nuclearity-dependent
    behavior; that is, at higher loadings, when oligomeric vanadia is present, it
    shifts from V═O bonds to linear V–O–V bonds in oligomers, leading to less selective
    oxidation due to the better reducibility. Our operando/transient spectroscopic
    results demonstrate the direct participation of the titania support in the reaction
    by influencing the degree of vanadia oligomerization and enabling rapid hydrogen
    transfer from propane to vanadia via Ti–OH groups on anatase, accelerating the
    rate-determining step of the initial C–H bond breakage. The broader applicability
    of the results is confirmed by the behavior of the ALD-synthesized sample, which
    resembles that of P25. Our results highlight the detailed level of mechanistic
    understanding accessible from multiple spectroscopic approaches, which can be
    readily transferred to other materials and/or reactions.
author:
- first_name: Leon
  full_name: Schumacher, Leon
  last_name: Schumacher
- first_name: Johannes
  full_name: Pfeiffer, Johannes
  last_name: Pfeiffer
- first_name: Jun
  full_name: Shen, Jun
  last_name: Shen
- first_name: Torsten
  full_name: Gutmann, Torsten
  id: '118165'
  last_name: Gutmann
- first_name: Hergen
  full_name: Breitzke, Hergen
  last_name: Breitzke
- first_name: Gerd
  full_name: Buntkowsky, Gerd
  last_name: Buntkowsky
- first_name: Kathrin
  full_name: Hofmann, Kathrin
  last_name: Hofmann
- first_name: Christian
  full_name: Hess, Christian
  last_name: Hess
citation:
  ama: Schumacher L, Pfeiffer J, Shen J, et al. Collaborative Mechanistic Effects
    between Vanadia and Titania during the Oxidative Dehydrogenation of Propane Investigated
    by Operando and Transient Spectroscopies. <i>ACS Catalysis</i>. 2023;13(12):8139–8160.
    doi:<a href="https://doi.org/10.1021/acscatal.3c01404">10.1021/acscatal.3c01404</a>
  apa: Schumacher, L., Pfeiffer, J., Shen, J., Gutmann, T., Breitzke, H., Buntkowsky,
    G., Hofmann, K., &#38; Hess, C. (2023). Collaborative Mechanistic Effects between
    Vanadia and Titania during the Oxidative Dehydrogenation of Propane Investigated
    by Operando and Transient Spectroscopies. <i>ACS Catalysis</i>, <i>13</i>(12),
    8139–8160. <a href="https://doi.org/10.1021/acscatal.3c01404">https://doi.org/10.1021/acscatal.3c01404</a>
  bibtex: '@article{Schumacher_Pfeiffer_Shen_Gutmann_Breitzke_Buntkowsky_Hofmann_Hess_2023,
    title={Collaborative Mechanistic Effects between Vanadia and Titania during the
    Oxidative Dehydrogenation of Propane Investigated by Operando and Transient Spectroscopies},
    volume={13}, DOI={<a href="https://doi.org/10.1021/acscatal.3c01404">10.1021/acscatal.3c01404</a>},
    number={12}, journal={ACS Catalysis}, publisher={American Chemical Society}, author={Schumacher,
    Leon and Pfeiffer, Johannes and Shen, Jun and Gutmann, Torsten and Breitzke, Hergen
    and Buntkowsky, Gerd and Hofmann, Kathrin and Hess, Christian}, year={2023}, pages={8139–8160}
    }'
  chicago: 'Schumacher, Leon, Johannes Pfeiffer, Jun Shen, Torsten Gutmann, Hergen
    Breitzke, Gerd Buntkowsky, Kathrin Hofmann, and Christian Hess. “Collaborative
    Mechanistic Effects between Vanadia and Titania during the Oxidative Dehydrogenation
    of Propane Investigated by Operando and Transient Spectroscopies.” <i>ACS Catalysis</i>
    13, no. 12 (2023): 8139–8160. <a href="https://doi.org/10.1021/acscatal.3c01404">https://doi.org/10.1021/acscatal.3c01404</a>.'
  ieee: 'L. Schumacher <i>et al.</i>, “Collaborative Mechanistic Effects between Vanadia
    and Titania during the Oxidative Dehydrogenation of Propane Investigated by Operando
    and Transient Spectroscopies,” <i>ACS Catalysis</i>, vol. 13, no. 12, pp. 8139–8160,
    2023, doi: <a href="https://doi.org/10.1021/acscatal.3c01404">10.1021/acscatal.3c01404</a>.'
  mla: Schumacher, Leon, et al. “Collaborative Mechanistic Effects between Vanadia
    and Titania during the Oxidative Dehydrogenation of Propane Investigated by Operando
    and Transient Spectroscopies.” <i>ACS Catalysis</i>, vol. 13, no. 12, American
    Chemical Society, 2023, pp. 8139–8160, doi:<a href="https://doi.org/10.1021/acscatal.3c01404">10.1021/acscatal.3c01404</a>.
  short: L. Schumacher, J. Pfeiffer, J. Shen, T. Gutmann, H. Breitzke, G. Buntkowsky,
    K. Hofmann, C. Hess, ACS Catalysis 13 (2023) 8139–8160.
date_created: 2026-02-07T16:09:39Z
date_updated: 2026-02-17T16:13:23Z
doi: 10.1021/acscatal.3c01404
extern: '1'
intvolume: '        13'
issue: '12'
language:
- iso: eng
page: 8139–8160
publication: ACS Catalysis
publisher: American Chemical Society
status: public
title: Collaborative Mechanistic Effects between Vanadia and Titania during the Oxidative
  Dehydrogenation of Propane Investigated by Operando and Transient Spectroscopies
type: journal_article
user_id: '100715'
volume: 13
year: '2023'
...
---
_id: '64008'
abstract:
- lang: eng
  text: The tailored design of bioactive materials based on cellulose or paper is
    still a challenging task. It requires detailed knowledge of the structure and
    interaction of the biofunctionalization with the carrier material at the nanoscale.
    In this work, the small peptide sequence Acetyl-Pro-Ala-Phe-Gly-OH (peptide 1)
    that can serve as a model for biofunctionalization is synthesized via solid-phase
    peptide synthesis, purified, and characterized by high-performance liquid chromatography
    (HPLC) and mass spectrometry (MS). The as-obtained peptide is bound to microcrystalline
    cellulose (MCC) via a wet chemical approach. Quantification of the peptide on
    the MCC carrier is performed by replacing l-proline (Pro) in the peptide sequence
    by 4-fluoro-l-proline (Pro(19F)) (peptide 2) and applying 19F magic angle spinning
    nuclear magnetic resonance (MAS NMR). Detailed characterization of the model system
    is provided by using 1H → 13C cross-polarization magic angle spinning (CP MAS
    NMR) combined with dynamic nuclear polarization (DNP) to enhance sensitivity.
    Analysis of the binding of the peptide on MCC necessitates the replacement of
    l-glycine (Gly) in the sequence by 13C-labeled l-glycine (Gly(13C)) (peptide 3).
    DNP-enhanced 13C–13C correlation experiments carried out with dipolar assisted
    rotational resonance (DARR) are then used to analyze the proximity between the
    model peptide and the MCC carrier. The strength of the dipolar coupling is estimated
    from the DNP-enhanced 1H → 13C CP MAS double-quantum rotational resonance (DQrotres)
    experiment. The obtained dipolar coupling between the 13C═O carbon of peptide
    3 and the C6 carbon of the cellulose is equal to a carbon–carbon distance of about
    two C–O bond lengths, which strongly suggests the binding of significant amounts
    of the peptide on MCC via an ester bond. The tailored design of bioactive materials
    based on cellulose or paper is still a challenging task. It requires detailed
    knowledge of the structure and interaction of the biofunctionalization with the
    carrier material at the nanoscale. In this work, the small peptide sequence Acetyl-Pro-Ala-Phe-Gly-OH
    (peptide 1) that can serve as a model for biofunctionalization is synthesized
    via solid-phase peptide synthesis, purified, and characterized by high-performance
    liquid chromatography (HPLC) and mass spectrometry (MS). The as-obtained peptide
    is bound to microcrystalline cellulose (MCC) via a wet chemical approach. Quantification
    of the peptide on the MCC carrier is performed by replacing l-proline (Pro) in
    the peptide sequence by 4-fluoro-l-proline (Pro(19F)) (peptide 2) and applying
    19F magic angle spinning nuclear magnetic resonance (MAS NMR). Detailed characterization
    of the model system is provided by using 1H → 13C cross-polarization magic angle
    spinning (CP MAS NMR) combined with dynamic nuclear polarization (DNP) to enhance
    sensitivity. Analysis of the binding of the peptide on MCC necessitates the replacement
    of l-glycine (Gly) in the sequence by 13C-labeled l-glycine (Gly(13C)) (peptide
    3). DNP-enhanced 13C–13C correlation experiments carried out with dipolar assisted
    rotational resonance (DARR) are then used to analyze the proximity between the
    model peptide and the MCC carrier. The strength of the dipolar coupling is estimated
    from the DNP-enhanced 1H → 13C CP MAS double-quantum rotational resonance (DQrotres)
    experiment. The obtained dipolar coupling between the 13C═O carbon of peptide
    3 and the C6 carbon of the cellulose is equal to a carbon–carbon distance of about
    two C–O bond lengths, which strongly suggests the binding of significant amounts
    of the peptide on MCC via an ester bond.
author:
- first_name: Waranya
  full_name: Limprasart, Waranya
  last_name: Limprasart
- first_name: Mark Valentin
  full_name: Höfler, Mark Valentin
  last_name: Höfler
- first_name: Nico
  full_name: Kunzmann, Nico
  last_name: Kunzmann
- first_name: Lorenz
  full_name: Rösler, Lorenz
  last_name: Rösler
- first_name: Kevin
  full_name: Herr, Kevin
  last_name: Herr
- first_name: Hergen
  full_name: Breitzke, Hergen
  last_name: Breitzke
- first_name: Torsten
  full_name: Gutmann, Torsten
  id: '118165'
  last_name: Gutmann
citation:
  ama: Limprasart W, Höfler MV, Kunzmann N, et al. Peptides as Model Systems for Biofunctionalizations
    of Cellulose─Synthesis and Structural Characterization by Advanced Solid-State
    Nuclear Magnetic Resonance Techniques. <i>The Journal of Physical Chemistry C</i>.
    2023;127(45):22129–22138. doi:<a href="https://doi.org/10.1021/acs.jpcc.3c05068">10.1021/acs.jpcc.3c05068</a>
  apa: Limprasart, W., Höfler, M. V., Kunzmann, N., Rösler, L., Herr, K., Breitzke,
    H., &#38; Gutmann, T. (2023). Peptides as Model Systems for Biofunctionalizations
    of Cellulose─Synthesis and Structural Characterization by Advanced Solid-State
    Nuclear Magnetic Resonance Techniques. <i>The Journal of Physical Chemistry C</i>,
    <i>127</i>(45), 22129–22138. <a href="https://doi.org/10.1021/acs.jpcc.3c05068">https://doi.org/10.1021/acs.jpcc.3c05068</a>
  bibtex: '@article{Limprasart_Höfler_Kunzmann_Rösler_Herr_Breitzke_Gutmann_2023,
    title={Peptides as Model Systems for Biofunctionalizations of Cellulose─Synthesis
    and Structural Characterization by Advanced Solid-State Nuclear Magnetic Resonance
    Techniques}, volume={127}, DOI={<a href="https://doi.org/10.1021/acs.jpcc.3c05068">10.1021/acs.jpcc.3c05068</a>},
    number={45}, journal={The Journal of Physical Chemistry C}, publisher={American
    Chemical Society}, author={Limprasart, Waranya and Höfler, Mark Valentin and Kunzmann,
    Nico and Rösler, Lorenz and Herr, Kevin and Breitzke, Hergen and Gutmann, Torsten},
    year={2023}, pages={22129–22138} }'
  chicago: 'Limprasart, Waranya, Mark Valentin Höfler, Nico Kunzmann, Lorenz Rösler,
    Kevin Herr, Hergen Breitzke, and Torsten Gutmann. “Peptides as Model Systems for
    Biofunctionalizations of Cellulose─Synthesis and Structural Characterization by
    Advanced Solid-State Nuclear Magnetic Resonance Techniques.” <i>The Journal of
    Physical Chemistry C</i> 127, no. 45 (2023): 22129–22138. <a href="https://doi.org/10.1021/acs.jpcc.3c05068">https://doi.org/10.1021/acs.jpcc.3c05068</a>.'
  ieee: 'W. Limprasart <i>et al.</i>, “Peptides as Model Systems for Biofunctionalizations
    of Cellulose─Synthesis and Structural Characterization by Advanced Solid-State
    Nuclear Magnetic Resonance Techniques,” <i>The Journal of Physical Chemistry C</i>,
    vol. 127, no. 45, pp. 22129–22138, 2023, doi: <a href="https://doi.org/10.1021/acs.jpcc.3c05068">10.1021/acs.jpcc.3c05068</a>.'
  mla: Limprasart, Waranya, et al. “Peptides as Model Systems for Biofunctionalizations
    of Cellulose─Synthesis and Structural Characterization by Advanced Solid-State
    Nuclear Magnetic Resonance Techniques.” <i>The Journal of Physical Chemistry C</i>,
    vol. 127, no. 45, American Chemical Society, 2023, pp. 22129–22138, doi:<a href="https://doi.org/10.1021/acs.jpcc.3c05068">10.1021/acs.jpcc.3c05068</a>.
  short: W. Limprasart, M.V. Höfler, N. Kunzmann, L. Rösler, K. Herr, H. Breitzke,
    T. Gutmann, The Journal of Physical Chemistry C 127 (2023) 22129–22138.
date_created: 2026-02-07T15:56:43Z
date_updated: 2026-02-17T16:15:27Z
doi: 10.1021/acs.jpcc.3c05068
extern: '1'
intvolume: '       127'
issue: '45'
language:
- iso: eng
page: 22129–22138
publication: The Journal of Physical Chemistry C
publication_identifier:
  issn:
  - 1932-7447
publisher: American Chemical Society
status: public
title: Peptides as Model Systems for Biofunctionalizations of Cellulose─Synthesis
  and Structural Characterization by Advanced Solid-State Nuclear Magnetic Resonance
  Techniques
type: journal_article
user_id: '100715'
volume: 127
year: '2023'
...
---
_id: '63998'
abstract:
- lang: eng
  text: Abstract The mechanochemical synthesis of porous covalent triazine networks
    (CTNs), exhibiting theoretically ideal C/N ratios and high specific surface areas,
    is presented. Employing this solvent-free approach allows to minimize the ecological
    impact of the synthesis by bypassing hazardous wastes, while simultaneously observing
    the reactions between the individual starting materials separately for the first
    time. Especially the role of dichloromethane needs to be reconsidered, functioning
    as a linker between the nitrogen-containing node cyanuric chloride and the aromatic
    monomer 1,3,5-triphenylbenzene, as proven by X-ray photoelectron spectroscopy
    and 1H â†’ 13C Cross-Polarization magic-angle-spinning nuclear magnetic resonance
    spectroscopy. This results in a drastic enhancement of the reaction rate, reducing
    the synthesis time down to 1 minute. Additionally, this linkage over a C1 bridge
    enables the incorporation of nitrogen into already synthesized polymers by post
    polymerization functionalization. The variation of the synthesis building blocks,
    namely the linker, node, and monomer, results in a variety of nitrogen-containing
    polymers with specific surface areas of up to 1500 m2 gâˆ’1. Therefore, the presented
    approach is capable to target the synthesis of various CTNs with a minimal use
    of chlorinated linker, rendering the concept as a sustainable alternative to the
    classical solution-based synthesis.
author:
- first_name: Annika
  full_name: Krusenbaum, Annika
  last_name: Krusenbaum
- first_name: Fabien Joel Leon
  full_name: Kraus, Fabien Joel Leon
  last_name: Kraus
- first_name: Stefanie
  full_name: Hutsch, Stefanie
  last_name: Hutsch
- first_name: Sven
  full_name: Grätz, Sven
  last_name: Grätz
- first_name: Mark Valentin
  full_name: Höfler, Mark Valentin
  last_name: Höfler
- first_name: Torsten
  full_name: Gutmann, Torsten
  id: '118165'
  last_name: Gutmann
- first_name: Lars
  full_name: Borchardt, Lars
  last_name: Borchardt
citation:
  ama: 'Krusenbaum A, Kraus FJL, Hutsch S, et al. The Rapid Mechanochemical Synthesis
    of Microporous Covalent Triazine Networks: Elucidating the Role of Chlorinated
    Linkers by a Solvent-Free Approach. <i>Advanced Sustainable Systems</i>. Published
    online 2023:2200477. doi:<a href="https://doi.org/10.1002/adsu.202200477">10.1002/adsu.202200477</a>'
  apa: 'Krusenbaum, A., Kraus, F. J. L., Hutsch, S., Grätz, S., Höfler, M. V., Gutmann,
    T., &#38; Borchardt, L. (2023). The Rapid Mechanochemical Synthesis of Microporous
    Covalent Triazine Networks: Elucidating the Role of Chlorinated Linkers by a Solvent-Free
    Approach. <i>Advanced Sustainable Systems</i>, 2200477. <a href="https://doi.org/10.1002/adsu.202200477">https://doi.org/10.1002/adsu.202200477</a>'
  bibtex: '@article{Krusenbaum_Kraus_Hutsch_Grätz_Höfler_Gutmann_Borchardt_2023, title={The
    Rapid Mechanochemical Synthesis of Microporous Covalent Triazine Networks: Elucidating
    the Role of Chlorinated Linkers by a Solvent-Free Approach}, DOI={<a href="https://doi.org/10.1002/adsu.202200477">10.1002/adsu.202200477</a>},
    journal={Advanced Sustainable Systems}, author={Krusenbaum, Annika and Kraus,
    Fabien Joel Leon and Hutsch, Stefanie and Grätz, Sven and Höfler, Mark Valentin
    and Gutmann, Torsten and Borchardt, Lars}, year={2023}, pages={2200477} }'
  chicago: 'Krusenbaum, Annika, Fabien Joel Leon Kraus, Stefanie Hutsch, Sven Grätz,
    Mark Valentin Höfler, Torsten Gutmann, and Lars Borchardt. “The Rapid Mechanochemical
    Synthesis of Microporous Covalent Triazine Networks: Elucidating the Role of Chlorinated
    Linkers by a Solvent-Free Approach.” <i>Advanced Sustainable Systems</i>, 2023,
    2200477. <a href="https://doi.org/10.1002/adsu.202200477">https://doi.org/10.1002/adsu.202200477</a>.'
  ieee: 'A. Krusenbaum <i>et al.</i>, “The Rapid Mechanochemical Synthesis of Microporous
    Covalent Triazine Networks: Elucidating the Role of Chlorinated Linkers by a Solvent-Free
    Approach,” <i>Advanced Sustainable Systems</i>, p. 2200477, 2023, doi: <a href="https://doi.org/10.1002/adsu.202200477">10.1002/adsu.202200477</a>.'
  mla: 'Krusenbaum, Annika, et al. “The Rapid Mechanochemical Synthesis of Microporous
    Covalent Triazine Networks: Elucidating the Role of Chlorinated Linkers by a Solvent-Free
    Approach.” <i>Advanced Sustainable Systems</i>, 2023, p. 2200477, doi:<a href="https://doi.org/10.1002/adsu.202200477">10.1002/adsu.202200477</a>.'
  short: A. Krusenbaum, F.J.L. Kraus, S. Hutsch, S. Grätz, M.V. Höfler, T. Gutmann,
    L. Borchardt, Advanced Sustainable Systems (2023) 2200477.
date_created: 2026-02-07T15:51:19Z
date_updated: 2026-02-17T16:15:58Z
doi: 10.1002/adsu.202200477
extern: '1'
language:
- iso: eng
page: '2200477'
publication: Advanced Sustainable Systems
status: public
title: 'The Rapid Mechanochemical Synthesis of Microporous Covalent Triazine Networks:
  Elucidating the Role of Chlorinated Linkers by a Solvent-Free Approach'
type: journal_article
user_id: '100715'
year: '2023'
...
---
_id: '63984'
abstract:
- lang: eng
  text: This study is seeking a better understanding of polyethylene glycol (PEG)
    as a solvent to promote its use in chemical synthesis. The effect of adding two
    solutes of interest, 2,2,6,6-tetramethylpiperidinyloxyl (TEMPO) and 5-tert-butylisophthalic
    acid (5-TBIPA) to PEG200 (average molar weight of 200 g·mol−1) on the solution
    density, viscosity, and self-diffusion coefficients is monitored in a temperature
    range of 298.15–358.15 K to deduce how these solutes interact with the PEG200
    solvent. The effect of water, the most common impurity in PEGs, is also monitored
    and found to be nearly negligibly small. Addition of (5-TBIPA) increases solution
    density and viscosity. Combined with the observation that 5-TBIPA consistently
    self-diffuses at about half the rate as PEG200 at all investigated experimental
    conditions, this suggests strong attractive solute–solvent interactions likely
    through hydrogen bonding interactions. In contrast, addition of TEMPO causes lower
    solution densities and viscosities suggesting that the solute–solvent interactions
    of TEMPO lead to an overall weakening of the intermolecular interactions present
    compared to neat PEG200. Inspection of the viscosity and self-diffusion temperature
    dependence reveals slight deviations from the Arrhenius equation. Interestingly,
    the activation energies obtained from the viscosity and the self-diffusion data
    are essentially identical in values suggesting that the same dynamic processes
    and thus the same activation barriers govern translational motion and momentum
    transfer in these PEG200 solutions.
author:
- first_name: Markus M.
  full_name: Hoffmann, Markus M.
  last_name: Hoffmann
- first_name: Nathaniel P.
  full_name: Randall, Nathaniel P.
  last_name: Randall
- first_name: Miray H.
  full_name: Apak, Miray H.
  last_name: Apak
- first_name: Nathaniel A.
  full_name: Paddock, Nathaniel A.
  last_name: Paddock
- first_name: Torsten
  full_name: Gutmann, Torsten
  id: '118165'
  last_name: Gutmann
- first_name: Gerd
  full_name: Buntkowsky, Gerd
  last_name: Buntkowsky
citation:
  ama: Hoffmann MM, Randall NP, Apak MH, Paddock NA, Gutmann T, Buntkowsky G. Solute–Solvent
    Interactions of 2,2,6,6-Tetramethylpiperidinyloxyl and 5-Tert-Butylisophthalic
    Acid in Polyethylene Glycol as Observed by Measurements of Density, Viscosity,
    and Self-Diffusion Coefficient. <i>Journal of Solution Chemistry</i>. 2023;52(6):685–707.
    doi:<a href="https://doi.org/10.1007/s10953-023-01265-4">10.1007/s10953-023-01265-4</a>
  apa: Hoffmann, M. M., Randall, N. P., Apak, M. H., Paddock, N. A., Gutmann, T.,
    &#38; Buntkowsky, G. (2023). Solute–Solvent Interactions of 2,2,6,6-Tetramethylpiperidinyloxyl
    and 5-Tert-Butylisophthalic Acid in Polyethylene Glycol as Observed by Measurements
    of Density, Viscosity, and Self-Diffusion Coefficient. <i>Journal of Solution
    Chemistry</i>, <i>52</i>(6), 685–707. <a href="https://doi.org/10.1007/s10953-023-01265-4">https://doi.org/10.1007/s10953-023-01265-4</a>
  bibtex: '@article{Hoffmann_Randall_Apak_Paddock_Gutmann_Buntkowsky_2023, title={Solute–Solvent
    Interactions of 2,2,6,6-Tetramethylpiperidinyloxyl and 5-Tert-Butylisophthalic
    Acid in Polyethylene Glycol as Observed by Measurements of Density, Viscosity,
    and Self-Diffusion Coefficient}, volume={52}, DOI={<a href="https://doi.org/10.1007/s10953-023-01265-4">10.1007/s10953-023-01265-4</a>},
    number={6}, journal={Journal of Solution Chemistry}, author={Hoffmann, Markus
    M. and Randall, Nathaniel P. and Apak, Miray H. and Paddock, Nathaniel A. and
    Gutmann, Torsten and Buntkowsky, Gerd}, year={2023}, pages={685–707} }'
  chicago: 'Hoffmann, Markus M., Nathaniel P. Randall, Miray H. Apak, Nathaniel A.
    Paddock, Torsten Gutmann, and Gerd Buntkowsky. “Solute–Solvent Interactions of
    2,2,6,6-Tetramethylpiperidinyloxyl and 5-Tert-Butylisophthalic Acid in Polyethylene
    Glycol as Observed by Measurements of Density, Viscosity, and Self-Diffusion Coefficient.”
    <i>Journal of Solution Chemistry</i> 52, no. 6 (2023): 685–707. <a href="https://doi.org/10.1007/s10953-023-01265-4">https://doi.org/10.1007/s10953-023-01265-4</a>.'
  ieee: 'M. M. Hoffmann, N. P. Randall, M. H. Apak, N. A. Paddock, T. Gutmann, and
    G. Buntkowsky, “Solute–Solvent Interactions of 2,2,6,6-Tetramethylpiperidinyloxyl
    and 5-Tert-Butylisophthalic Acid in Polyethylene Glycol as Observed by Measurements
    of Density, Viscosity, and Self-Diffusion Coefficient,” <i>Journal of Solution
    Chemistry</i>, vol. 52, no. 6, pp. 685–707, 2023, doi: <a href="https://doi.org/10.1007/s10953-023-01265-4">10.1007/s10953-023-01265-4</a>.'
  mla: Hoffmann, Markus M., et al. “Solute–Solvent Interactions of 2,2,6,6-Tetramethylpiperidinyloxyl
    and 5-Tert-Butylisophthalic Acid in Polyethylene Glycol as Observed by Measurements
    of Density, Viscosity, and Self-Diffusion Coefficient.” <i>Journal of Solution
    Chemistry</i>, vol. 52, no. 6, 2023, pp. 685–707, doi:<a href="https://doi.org/10.1007/s10953-023-01265-4">10.1007/s10953-023-01265-4</a>.
  short: M.M. Hoffmann, N.P. Randall, M.H. Apak, N.A. Paddock, T. Gutmann, G. Buntkowsky,
    Journal of Solution Chemistry 52 (2023) 685–707.
date_created: 2026-02-07T15:45:09Z
date_updated: 2026-02-17T16:16:51Z
doi: 10.1007/s10953-023-01265-4
extern: '1'
intvolume: '        52'
issue: '6'
language:
- iso: eng
page: 685–707
publication: Journal of Solution Chemistry
status: public
title: Solute–Solvent Interactions of 2,2,6,6-Tetramethylpiperidinyloxyl and 5-Tert-Butylisophthalic
  Acid in Polyethylene Glycol as Observed by Measurements of Density, Viscosity, and
  Self-Diffusion Coefficient
type: journal_article
user_id: '100715'
volume: 52
year: '2023'
...
---
_id: '63987'
abstract:
- lang: eng
  text: An efficient approach employing 4-dimethylaminopyridine and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide
    hydrochloride as the coupling reagent is presented, which enables the functionalization
    of cotton linter paper substrates with the 19F spin label N-boc-cis-4-fluoro-l-proline.
    This spin label can be easily quantified by 19F magic angle spinning (MAS) NMR
    experiments to determine its loading on paper substrates. During the functionalization,
    the spin label stays intact, as confirmed by the 1Hâ€“19F heterocorrelation (1HÂ
    â†’Â 19F CP MAS FSLG HETCOR) experiments. In combination with dynamic nuclear
    polarization (19F MAS DNP), the N-boc-cis-4-fluoro-l-proline spin label allows
    us to inspect 1 Î¼mol/g and even lower molecule loadings on paper substrates,
    providing a highly sensitive local probe to analyze the structure of biofunctionalizations
    at the nanoscale on paper substrates in the future. An efficient approach employing
    4-dimethylaminopyridine and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride
    as the coupling reagent is presented, which enables the functionalization of cotton
    linter paper substrates with the 19F spin label N-boc-cis-4-fluoro-l-proline.
    This spin label can be easily quantified by 19F magic angle spinning (MAS) NMR
    experiments to determine its loading on paper substrates. During the functionalization,
    the spin label stays intact, as confirmed by the 1Hâ€“19F heterocorrelation (1HÂ
    â†’Â 19F CP MAS FSLG HETCOR) experiments. In combination with dynamic nuclear
    polarization (19F MAS DNP), the N-boc-cis-4-fluoro-l-proline spin label allows
    us to inspect 1 Î¼mol/g and even lower molecule loadings on paper substrates,
    providing a highly sensitive local probe to analyze the structure of biofunctionalizations
    at the nanoscale on paper substrates in the future.
author:
- first_name: Mark V.
  full_name: Höfler, Mark V.
  last_name: Höfler
- first_name: Waranya
  full_name: Limprasart, Waranya
  last_name: Limprasart
- first_name: Lorenz
  full_name: Rösler, Lorenz
  last_name: Rösler
- first_name: Max
  full_name: Fleckenstein, Max
  last_name: Fleckenstein
- first_name: Martin
  full_name: Brodrecht, Martin
  last_name: Brodrecht
- first_name: Kevin
  full_name: Herr, Kevin
  last_name: Herr
- first_name: Jan-Lukas
  full_name: Schäfer, Jan-Lukas
  last_name: Schäfer
- first_name: Markus
  full_name: Biesalski, Markus
  last_name: Biesalski
- first_name: Hergen
  full_name: Breitzke, Hergen
  last_name: Breitzke
- first_name: Torsten
  full_name: Gutmann, Torsten
  id: '118165'
  last_name: Gutmann
citation:
  ama: Höfler MV, Limprasart W, Rösler L, et al. Fluorine-Labeled N-Boc-l-proline
    as a Marker for Solid-State NMR Characterization of Biofunctionalizations on Paper
    Substrates. <i>Journal of Physical Chemistry C</i>. 2023;127(7):3570–3578.
  apa: Höfler, M. V., Limprasart, W., Rösler, L., Fleckenstein, M., Brodrecht, M.,
    Herr, K., Schäfer, J.-L., Biesalski, M., Breitzke, H., &#38; Gutmann, T. (2023).
    Fluorine-Labeled N-Boc-l-proline as a Marker for Solid-State NMR Characterization
    of Biofunctionalizations on Paper Substrates. <i>Journal of Physical Chemistry
    C</i>, <i>127</i>(7), 3570–3578.
  bibtex: '@article{Höfler_Limprasart_Rösler_Fleckenstein_Brodrecht_Herr_Schäfer_Biesalski_Breitzke_Gutmann_2023,
    title={Fluorine-Labeled N-Boc-l-proline as a Marker for Solid-State NMR Characterization
    of Biofunctionalizations on Paper Substrates}, volume={127}, number={7}, journal={Journal
    of Physical Chemistry C}, publisher={American Chemical Society}, author={Höfler,
    Mark V. and Limprasart, Waranya and Rösler, Lorenz and Fleckenstein, Max and Brodrecht,
    Martin and Herr, Kevin and Schäfer, Jan-Lukas and Biesalski, Markus and Breitzke,
    Hergen and Gutmann, Torsten}, year={2023}, pages={3570–3578} }'
  chicago: 'Höfler, Mark V., Waranya Limprasart, Lorenz Rösler, Max Fleckenstein,
    Martin Brodrecht, Kevin Herr, Jan-Lukas Schäfer, Markus Biesalski, Hergen Breitzke,
    and Torsten Gutmann. “Fluorine-Labeled N-Boc-l-Proline as a Marker for Solid-State
    NMR Characterization of Biofunctionalizations on Paper Substrates.” <i>Journal
    of Physical Chemistry C</i> 127, no. 7 (2023): 3570–3578.'
  ieee: M. V. Höfler <i>et al.</i>, “Fluorine-Labeled N-Boc-l-proline as a Marker
    for Solid-State NMR Characterization of Biofunctionalizations on Paper Substrates,”
    <i>Journal of Physical Chemistry C</i>, vol. 127, no. 7, pp. 3570–3578, 2023.
  mla: Höfler, Mark V., et al. “Fluorine-Labeled N-Boc-l-Proline as a Marker for Solid-State
    NMR Characterization of Biofunctionalizations on Paper Substrates.” <i>Journal
    of Physical Chemistry C</i>, vol. 127, no. 7, American Chemical Society, 2023,
    pp. 3570–3578.
  short: M.V. Höfler, W. Limprasart, L. Rösler, M. Fleckenstein, M. Brodrecht, K.
    Herr, J.-L. Schäfer, M. Biesalski, H. Breitzke, T. Gutmann, Journal of Physical
    Chemistry C 127 (2023) 3570–3578.
date_created: 2026-02-07T15:46:14Z
date_updated: 2026-02-17T16:16:46Z
extern: '1'
intvolume: '       127'
issue: '7'
language:
- iso: eng
page: 3570–3578
publication: Journal of Physical Chemistry C
publication_identifier:
  issn:
  - 1932-7447
publisher: American Chemical Society
status: public
title: Fluorine-Labeled N-Boc-l-proline as a Marker for Solid-State NMR Characterization
  of Biofunctionalizations on Paper Substrates
type: journal_article
user_id: '100715'
volume: 127
year: '2023'
...
---
_id: '63971'
abstract:
- lang: eng
  text: 'The physicochemical effects of decorating pore walls of high surface area
    materials with functional groups are not sufficiently understood, despite the
    use of these materials in a multitude of applications such as catalysis, separations,
    or drug delivery. In this study, the influence of 3-amino-propyl triethoxysilane
    (APTES)-modified SBA-15 on the dynamics of deuterated ethylene glycol (EG-d4)
    is inspected by comparing three systems: EG-d4 in the bulk phase (sample 1), EG-d4
    confined in SBA-15 (sample 2), and EG-d4 confined in SBA-15 modified with APTES
    (sample 3). The phase behavior (i.e., melting, crystallization, glass formation,
    etc.) of EG-d4 in these three systems is studied by differential scanning calorimetry.
    Through line shape analysis of the 2H solid-state NMR (2H ssNMR) spectra of the
    three systems recorded at different temperatures, two signal patterns, (i) a Lorentzian
    (liquid-like) and (ii) a Pake pattern (solid-like), are identified from which
    the distribution of activation energies for the dynamic processes is calculated
    employing a two-phase model. The physicochemical effects of decorating pore walls
    of high surface area materials with functional groups are not sufficiently understood,
    despite the use of these materials in a multitude of applications such as catalysis,
    separations, or drug delivery. In this study, the influence of 3-amino-propyl
    triethoxysilane (APTES)-modified SBA-15 on the dynamics of deuterated ethylene
    glycol (EG-d4) is inspected by comparing three systems: EG-d4 in the bulk phase
    (sample 1), EG-d4 confined in SBA-15 (sample 2), and EG-d4 confined in SBA-15
    modified with APTES (sample 3). The phase behavior (i.e., melting, crystallization,
    glass formation, etc.) of EG-d4 in these three systems is studied by differential
    scanning calorimetry. Through line shape analysis of the 2H solid-state NMR (2H
    ssNMR) spectra of the three systems recorded at different temperatures, two signal
    patterns, (i) a Lorentzian (liquid-like) and (ii) a Pake pattern (solid-like),
    are identified from which the distribution of activation energies for the dynamic
    processes is calculated employing a two-phase model.'
author:
- first_name: Nadia B.
  full_name: Haro Mares, Nadia B.
  last_name: Haro Mares
- first_name: Martin
  full_name: Brodrecht, Martin
  last_name: Brodrecht
- first_name: Till
  full_name: Wissel, Till
  last_name: Wissel
- first_name: Sonja C.
  full_name: Döller, Sonja C.
  last_name: Döller
- first_name: Lorenz
  full_name: Rösler, Lorenz
  last_name: Rösler
- first_name: Hergen
  full_name: Breitzke, Hergen
  last_name: Breitzke
- first_name: Markus M.
  full_name: Hoffmann, Markus M.
  last_name: Hoffmann
- first_name: Torsten
  full_name: Gutmann, Torsten
  id: '118165'
  last_name: Gutmann
- first_name: Gerd
  full_name: Buntkowsky, Gerd
  last_name: Buntkowsky
citation:
  ama: Haro Mares NB, Brodrecht M, Wissel T, et al. Influence of APTES-Decorated Mesoporous
    Silica on the Dynamics of Ethylene Glycol Molecules─Insights from Variable Temperature
    2H Solid-State NMR. <i>The Journal of Physical Chemistry C</i>. 2023;127(39):19735–19746.
    doi:<a href="https://doi.org/10.1021/acs.jpcc.3c03671">10.1021/acs.jpcc.3c03671</a>
  apa: Haro Mares, N. B., Brodrecht, M., Wissel, T., Döller, S. C., Rösler, L., Breitzke,
    H., Hoffmann, M. M., Gutmann, T., &#38; Buntkowsky, G. (2023). Influence of APTES-Decorated
    Mesoporous Silica on the Dynamics of Ethylene Glycol Molecules─Insights from Variable
    Temperature 2H Solid-State NMR. <i>The Journal of Physical Chemistry C</i>, <i>127</i>(39),
    19735–19746. <a href="https://doi.org/10.1021/acs.jpcc.3c03671">https://doi.org/10.1021/acs.jpcc.3c03671</a>
  bibtex: '@article{Haro Mares_Brodrecht_Wissel_Döller_Rösler_Breitzke_Hoffmann_Gutmann_Buntkowsky_2023,
    title={Influence of APTES-Decorated Mesoporous Silica on the Dynamics of Ethylene
    Glycol Molecules─Insights from Variable Temperature 2H Solid-State NMR}, volume={127},
    DOI={<a href="https://doi.org/10.1021/acs.jpcc.3c03671">10.1021/acs.jpcc.3c03671</a>},
    number={39}, journal={The Journal of Physical Chemistry C}, publisher={American
    Chemical Society}, author={Haro Mares, Nadia B. and Brodrecht, Martin and Wissel,
    Till and Döller, Sonja C. and Rösler, Lorenz and Breitzke, Hergen and Hoffmann,
    Markus M. and Gutmann, Torsten and Buntkowsky, Gerd}, year={2023}, pages={19735–19746}
    }'
  chicago: 'Haro Mares, Nadia B., Martin Brodrecht, Till Wissel, Sonja C. Döller,
    Lorenz Rösler, Hergen Breitzke, Markus M. Hoffmann, Torsten Gutmann, and Gerd
    Buntkowsky. “Influence of APTES-Decorated Mesoporous Silica on the Dynamics of
    Ethylene Glycol Molecules─Insights from Variable Temperature 2H Solid-State NMR.”
    <i>The Journal of Physical Chemistry C</i> 127, no. 39 (2023): 19735–19746. <a
    href="https://doi.org/10.1021/acs.jpcc.3c03671">https://doi.org/10.1021/acs.jpcc.3c03671</a>.'
  ieee: 'N. B. Haro Mares <i>et al.</i>, “Influence of APTES-Decorated Mesoporous
    Silica on the Dynamics of Ethylene Glycol Molecules─Insights from Variable Temperature
    2H Solid-State NMR,” <i>The Journal of Physical Chemistry C</i>, vol. 127, no.
    39, pp. 19735–19746, 2023, doi: <a href="https://doi.org/10.1021/acs.jpcc.3c03671">10.1021/acs.jpcc.3c03671</a>.'
  mla: Haro Mares, Nadia B., et al. “Influence of APTES-Decorated Mesoporous Silica
    on the Dynamics of Ethylene Glycol Molecules─Insights from Variable Temperature
    2H Solid-State NMR.” <i>The Journal of Physical Chemistry C</i>, vol. 127, no.
    39, American Chemical Society, 2023, pp. 19735–19746, doi:<a href="https://doi.org/10.1021/acs.jpcc.3c03671">10.1021/acs.jpcc.3c03671</a>.
  short: N.B. Haro Mares, M. Brodrecht, T. Wissel, S.C. Döller, L. Rösler, H. Breitzke,
    M.M. Hoffmann, T. Gutmann, G. Buntkowsky, The Journal of Physical Chemistry C
    127 (2023) 19735–19746.
date_created: 2026-02-07T15:40:57Z
date_updated: 2026-02-17T16:17:28Z
doi: 10.1021/acs.jpcc.3c03671
extern: '1'
intvolume: '       127'
issue: '39'
language:
- iso: eng
page: 19735–19746
publication: The Journal of Physical Chemistry C
publication_identifier:
  issn:
  - 1932-7447
publisher: American Chemical Society
status: public
title: Influence of APTES-Decorated Mesoporous Silica on the Dynamics of Ethylene
  Glycol Molecules─Insights from Variable Temperature 2H Solid-State NMR
type: journal_article
user_id: '100715'
volume: 127
year: '2023'
...
---
_id: '63946'
abstract:
- lang: eng
  text: Two different mesoporous silica materials (SBA-15 and MCM 41) were impregnated
    with four different, commercially available surfactants, namely, E5, PEG 200,
    C10E6, and Triton X-100. Differential scanning calorimetry was employed to confirm
    the confinement of the surfactants in the pores of their host materials. Dynamic
    nuclear polarization enhanced solid state 13C magic angle spinning (MAS) nuclear
    magnetic resonance (NMR) spectra were recorded for these materials, showing that
    both the direct as well as the indirect polarization transfer pathways are active
    for the carbons of the polyethylene glycol moieties of the surfactants. The presence
    of the indirect polarization pathway implies the presence of molecular motion
    with correlation times faster than the inverse Larmor frequency of the observed
    signals. The intensities of the signals were determined, and an approach based
    on relative intensities was employed to ensure comparability throughout the samples.
    From these data, the interactions of the surfactants with the pore walls could
    be determined. Additionally, a model describing the surfactants’ arrangement in
    the pores was developed. It was concluded that all carbons of the hydrophilic
    surfactants, E5 and PEG 200, interact with the silica walls in a similar fashion,
    leading to similar polarization transfer pathway patterns for all observed signals.
    For the amphiphilic surfactants C10E6 and Triton X-100, the terminal hydroxyl
    group mediates the majority of the interactions with the pore walls and the polarizing
    agent. Two different mesoporous silica materials (SBA-15 and MCM 41) were impregnated
    with four different, commercially available surfactants, namely, E5, PEG 200,
    C10E6, and Triton X-100. Differential scanning calorimetry was employed to confirm
    the confinement of the surfactants in the pores of their host materials. Dynamic
    nuclear polarization enhanced solid state 13C magic angle spinning (MAS) nuclear
    magnetic resonance (NMR) spectra were recorded for these materials, showing that
    both the direct as well as the indirect polarization transfer pathways are active
    for the carbons of the polyethylene glycol moieties of the surfactants. The presence
    of the indirect polarization pathway implies the presence of molecular motion
    with correlation times faster than the inverse Larmor frequency of the observed
    signals. The intensities of the signals were determined, and an approach based
    on relative intensities was employed to ensure comparability throughout the samples.
    From these data, the interactions of the surfactants with the pore walls could
    be determined. Additionally, a model describing the surfactants’ arrangement in
    the pores was developed. It was concluded that all carbons of the hydrophilic
    surfactants, E5 and PEG 200, interact with the silica walls in a similar fashion,
    leading to similar polarization transfer pathway patterns for all observed signals.
    For the amphiphilic surfactants C10E6 and Triton X-100, the terminal hydroxyl
    group mediates the majority of the interactions with the pore walls and the polarizing
    agent.
author:
- first_name: Sonja C.
  full_name: Döller, Sonja C.
  last_name: Döller
- first_name: Martin
  full_name: Brodrecht, Martin
  last_name: Brodrecht
- first_name: Torsten
  full_name: Gutmann, Torsten
  id: '118165'
  last_name: Gutmann
- first_name: Markus
  full_name: Hoffmann, Markus
  last_name: Hoffmann
- first_name: Gerd
  full_name: Buntkowsky, Gerd
  last_name: Buntkowsky
citation:
  ama: Döller SC, Brodrecht M, Gutmann T, Hoffmann M, Buntkowsky G. Direct and Indirect
    DNP NMR Uncovers the Interplay of Surfactants with Their Mesoporous Host Material.
    <i>The Journal of Physical Chemistry C</i>. 2023;127(25):12125–12134. doi:<a href="https://doi.org/10.1021/acs.jpcc.3c01946">10.1021/acs.jpcc.3c01946</a>
  apa: Döller, S. C., Brodrecht, M., Gutmann, T., Hoffmann, M., &#38; Buntkowsky,
    G. (2023). Direct and Indirect DNP NMR Uncovers the Interplay of Surfactants with
    Their Mesoporous Host Material. <i>The Journal of Physical Chemistry C</i>, <i>127</i>(25),
    12125–12134. <a href="https://doi.org/10.1021/acs.jpcc.3c01946">https://doi.org/10.1021/acs.jpcc.3c01946</a>
  bibtex: '@article{Döller_Brodrecht_Gutmann_Hoffmann_Buntkowsky_2023, title={Direct
    and Indirect DNP NMR Uncovers the Interplay of Surfactants with Their Mesoporous
    Host Material}, volume={127}, DOI={<a href="https://doi.org/10.1021/acs.jpcc.3c01946">10.1021/acs.jpcc.3c01946</a>},
    number={25}, journal={The Journal of Physical Chemistry C}, publisher={American
    Chemical Society}, author={Döller, Sonja C. and Brodrecht, Martin and Gutmann,
    Torsten and Hoffmann, Markus and Buntkowsky, Gerd}, year={2023}, pages={12125–12134}
    }'
  chicago: 'Döller, Sonja C., Martin Brodrecht, Torsten Gutmann, Markus Hoffmann,
    and Gerd Buntkowsky. “Direct and Indirect DNP NMR Uncovers the Interplay of Surfactants
    with Their Mesoporous Host Material.” <i>The Journal of Physical Chemistry C</i>
    127, no. 25 (2023): 12125–12134. <a href="https://doi.org/10.1021/acs.jpcc.3c01946">https://doi.org/10.1021/acs.jpcc.3c01946</a>.'
  ieee: 'S. C. Döller, M. Brodrecht, T. Gutmann, M. Hoffmann, and G. Buntkowsky, “Direct
    and Indirect DNP NMR Uncovers the Interplay of Surfactants with Their Mesoporous
    Host Material,” <i>The Journal of Physical Chemistry C</i>, vol. 127, no. 25,
    pp. 12125–12134, 2023, doi: <a href="https://doi.org/10.1021/acs.jpcc.3c01946">10.1021/acs.jpcc.3c01946</a>.'
  mla: Döller, Sonja C., et al. “Direct and Indirect DNP NMR Uncovers the Interplay
    of Surfactants with Their Mesoporous Host Material.” <i>The Journal of Physical
    Chemistry C</i>, vol. 127, no. 25, American Chemical Society, 2023, pp. 12125–12134,
    doi:<a href="https://doi.org/10.1021/acs.jpcc.3c01946">10.1021/acs.jpcc.3c01946</a>.
  short: S.C. Döller, M. Brodrecht, T. Gutmann, M. Hoffmann, G. Buntkowsky, The Journal
    of Physical Chemistry C 127 (2023) 12125–12134.
date_created: 2026-02-07T09:12:13Z
date_updated: 2026-02-17T16:18:30Z
doi: 10.1021/acs.jpcc.3c01946
extern: '1'
intvolume: '       127'
issue: '25'
language:
- iso: eng
page: 12125–12134
publication: The Journal of Physical Chemistry C
publication_identifier:
  issn:
  - 1932-7447
publisher: American Chemical Society
status: public
title: Direct and Indirect DNP NMR Uncovers the Interplay of Surfactants with Their
  Mesoporous Host Material
type: journal_article
user_id: '100715'
volume: 127
year: '2023'
...
---
_id: '63922'
author:
- first_name: Nargiz B.
  full_name: Asanbaeva, Nargiz B.
  last_name: Asanbaeva
- first_name: Sergey A.
  full_name: Dobrynin, Sergey A.
  last_name: Dobrynin
- first_name: Denis A.
  full_name: Morozov, Denis A.
  last_name: Morozov
- first_name: Nadia
  full_name: Haro-Mares, Nadia
  last_name: Haro-Mares
- first_name: Torsten
  full_name: Gutmann, Torsten
  id: '118165'
  last_name: Gutmann
- first_name: Gerd
  full_name: Buntkowsky, Gerd
  last_name: Buntkowsky
- first_name: Elena G.
  full_name: Bagryanskaya, Elena G.
  last_name: Bagryanskaya
citation:
  ama: Asanbaeva NB, Dobrynin SA, Morozov DA, et al. An EPR Study on Highly Stable
    Nitroxyl-Nitroxyl Biradicals for Dynamic Nuclear Polarization Applications at
    High Magnetic Fields. <i>Molecules</i>. 2023;28(4):1926. doi:<a href="https://doi.org/10.3390/molecules28041926">10.3390/molecules28041926</a>
  apa: Asanbaeva, N. B., Dobrynin, S. A., Morozov, D. A., Haro-Mares, N., Gutmann,
    T., Buntkowsky, G., &#38; Bagryanskaya, E. G. (2023). An EPR Study on Highly Stable
    Nitroxyl-Nitroxyl Biradicals for Dynamic Nuclear Polarization Applications at
    High Magnetic Fields. <i>Molecules</i>, <i>28</i>(4), 1926. <a href="https://doi.org/10.3390/molecules28041926">https://doi.org/10.3390/molecules28041926</a>
  bibtex: '@article{Asanbaeva_Dobrynin_Morozov_Haro-Mares_Gutmann_Buntkowsky_Bagryanskaya_2023,
    title={An EPR Study on Highly Stable Nitroxyl-Nitroxyl Biradicals for Dynamic
    Nuclear Polarization Applications at High Magnetic Fields}, volume={28}, DOI={<a
    href="https://doi.org/10.3390/molecules28041926">10.3390/molecules28041926</a>},
    number={4}, journal={Molecules}, author={Asanbaeva, Nargiz B. and Dobrynin, Sergey
    A. and Morozov, Denis A. and Haro-Mares, Nadia and Gutmann, Torsten and Buntkowsky,
    Gerd and Bagryanskaya, Elena G.}, year={2023}, pages={1926} }'
  chicago: 'Asanbaeva, Nargiz B., Sergey A. Dobrynin, Denis A. Morozov, Nadia Haro-Mares,
    Torsten Gutmann, Gerd Buntkowsky, and Elena G. Bagryanskaya. “An EPR Study on
    Highly Stable Nitroxyl-Nitroxyl Biradicals for Dynamic Nuclear Polarization Applications
    at High Magnetic Fields.” <i>Molecules</i> 28, no. 4 (2023): 1926. <a href="https://doi.org/10.3390/molecules28041926">https://doi.org/10.3390/molecules28041926</a>.'
  ieee: 'N. B. Asanbaeva <i>et al.</i>, “An EPR Study on Highly Stable Nitroxyl-Nitroxyl
    Biradicals for Dynamic Nuclear Polarization Applications at High Magnetic Fields,”
    <i>Molecules</i>, vol. 28, no. 4, p. 1926, 2023, doi: <a href="https://doi.org/10.3390/molecules28041926">10.3390/molecules28041926</a>.'
  mla: Asanbaeva, Nargiz B., et al. “An EPR Study on Highly Stable Nitroxyl-Nitroxyl
    Biradicals for Dynamic Nuclear Polarization Applications at High Magnetic Fields.”
    <i>Molecules</i>, vol. 28, no. 4, 2023, p. 1926, doi:<a href="https://doi.org/10.3390/molecules28041926">10.3390/molecules28041926</a>.
  short: N.B. Asanbaeva, S.A. Dobrynin, D.A. Morozov, N. Haro-Mares, T. Gutmann, G.
    Buntkowsky, E.G. Bagryanskaya, Molecules 28 (2023) 1926.
date_created: 2026-02-07T08:57:19Z
date_updated: 2026-02-20T08:12:12Z
doi: 10.3390/molecules28041926
extern: '1'
intvolume: '        28'
issue: '4'
language:
- iso: eng
page: '1926'
publication: Molecules
publication_identifier:
  issn:
  - 1420-3049
status: public
title: An EPR Study on Highly Stable Nitroxyl-Nitroxyl Biradicals for Dynamic Nuclear
  Polarization Applications at High Magnetic Fields
type: journal_article
user_id: '100715'
volume: 28
year: '2023'
...
---
_id: '64042'
abstract:
- lang: eng
  text: Abstract Polymer-derived silicon carbonitride ceramic (SiCN) is used as an
    electrode material to prepare cylindrical sodium/sodium ion cells for solid-state
    NMR investigations. During galvanostatic cycling structural changes of the environment
    of sodium/sodium ions are investigated by applying 23Na in-situ solid-state NMR.
    Changes of the signals assigned to sodium metal, intercalated sodium cation and
    sodium cation originating from the electrolyte are monitored as well as the occurrence
    of an additional signal in the region of metallic sodium. The intensity of this
    additional signal changes periodically with the cycling process indicating the
    reversibility of structures formed and deformed during the galvanostatic cycling.
    To identify interactions of sodium/sodium ions with the SiCN electrode materials,
    the cycled SiCN material is studied by 23Na ex-situ MAS NMR at high spinning rates
    of 20 and 50â€…kHz to obtain appropriate spectral resolution.
author:
- first_name: Edina
  full_name: Sic, Edina
  last_name: Sic
- first_name: Marco
  full_name: Melzi d’Eril, Marco
  last_name: Melzi d’Eril
- first_name: Konstantin
  full_name: Schutjajew, Konstantin
  last_name: Schutjajew
- first_name: Magdalena J.
  full_name: Graczyk-Zajac, Magdalena J.
  last_name: Graczyk-Zajac
- first_name: Hergen
  full_name: Breitzke, Hergen
  last_name: Breitzke
- first_name: Ralf
  full_name: Riedel, Ralf
  last_name: Riedel
- first_name: Martin
  full_name: Oschatz, Martin
  last_name: Oschatz
- first_name: Torsten
  full_name: Gutmann, Torsten
  id: '118165'
  last_name: Gutmann
- first_name: Gerd
  full_name: Buntkowsky, Gerd
  last_name: Buntkowsky
citation:
  ama: Sic E, Melzi d’Eril M, Schutjajew K, et al. SiCN Ceramics as Electrode Materials
    for Sodium/Sodium Ion Cells Insights from 23Na In-Situ Solid-State NMR. <i>Batteries
    and Supercaps</i>. 2022;5:e202200066. doi:<a href="https://doi.org/10.1002/batt.202200066">10.1002/batt.202200066</a>
  apa: Sic, E., Melzi d’Eril, M., Schutjajew, K., Graczyk-Zajac, M. J., Breitzke,
    H., Riedel, R., Oschatz, M., Gutmann, T., &#38; Buntkowsky, G. (2022). SiCN Ceramics
    as Electrode Materials for Sodium/Sodium Ion Cells Insights from 23Na In-Situ
    Solid-State NMR. <i>Batteries and Supercaps</i>, <i>5</i>, e202200066. <a href="https://doi.org/10.1002/batt.202200066">https://doi.org/10.1002/batt.202200066</a>
  bibtex: '@article{Sic_Melzi d’Eril_Schutjajew_Graczyk-Zajac_Breitzke_Riedel_Oschatz_Gutmann_Buntkowsky_2022,
    title={SiCN Ceramics as Electrode Materials for Sodium/Sodium Ion Cells Insights
    from 23Na In-Situ Solid-State NMR}, volume={5}, DOI={<a href="https://doi.org/10.1002/batt.202200066">10.1002/batt.202200066</a>},
    journal={Batteries and Supercaps}, author={Sic, Edina and Melzi d’Eril, Marco
    and Schutjajew, Konstantin and Graczyk-Zajac, Magdalena J. and Breitzke, Hergen
    and Riedel, Ralf and Oschatz, Martin and Gutmann, Torsten and Buntkowsky, Gerd},
    year={2022}, pages={e202200066} }'
  chicago: 'Sic, Edina, Marco Melzi d’Eril, Konstantin Schutjajew, Magdalena J. Graczyk-Zajac,
    Hergen Breitzke, Ralf Riedel, Martin Oschatz, Torsten Gutmann, and Gerd Buntkowsky.
    “SiCN Ceramics as Electrode Materials for Sodium/Sodium Ion Cells Insights from
    23Na In-Situ Solid-State NMR.” <i>Batteries and Supercaps</i> 5 (2022): e202200066.
    <a href="https://doi.org/10.1002/batt.202200066">https://doi.org/10.1002/batt.202200066</a>.'
  ieee: 'E. Sic <i>et al.</i>, “SiCN Ceramics as Electrode Materials for Sodium/Sodium
    Ion Cells Insights from 23Na In-Situ Solid-State NMR,” <i>Batteries and Supercaps</i>,
    vol. 5, p. e202200066, 2022, doi: <a href="https://doi.org/10.1002/batt.202200066">10.1002/batt.202200066</a>.'
  mla: Sic, Edina, et al. “SiCN Ceramics as Electrode Materials for Sodium/Sodium
    Ion Cells Insights from 23Na In-Situ Solid-State NMR.” <i>Batteries and Supercaps</i>,
    vol. 5, 2022, p. e202200066, doi:<a href="https://doi.org/10.1002/batt.202200066">10.1002/batt.202200066</a>.
  short: E. Sic, M. Melzi d’Eril, K. Schutjajew, M.J. Graczyk-Zajac, H. Breitzke,
    R. Riedel, M. Oschatz, T. Gutmann, G. Buntkowsky, Batteries and Supercaps 5 (2022)
    e202200066.
date_created: 2026-02-07T16:10:25Z
date_updated: 2026-02-17T16:13:15Z
doi: 10.1002/batt.202200066
extern: '1'
intvolume: '         5'
language:
- iso: eng
page: e202200066
publication: Batteries and Supercaps
status: public
title: SiCN Ceramics as Electrode Materials for Sodium/Sodium Ion Cells Insights from
  23Na In-Situ Solid-State NMR
type: journal_article
user_id: '100715'
volume: 5
year: '2022'
...
---
_id: '64030'
abstract:
- lang: eng
  text: A novel, efficient approach for the functionalization of microcrystalline
    cellulose (MCC) is presented. The as-obtained material allows the immobilization
    of chiral dirhodium catalysts preserving their enantioselectivity in asymmetric
    cyclopropanation reactions. As model, microcrystalline cellulose is modified with
    a polyethylene glycol derived linker, and Rh-2(S-DOSP)(4) is grafted on the material
    to produce a heterogeneous catalyst. SEM images at different stages of the immobilization
    show an unchanging uniform morphology, providing constantly good separation characteristics.
    The modification of the cellulose material with the polyethylene derived linker
    and the immobilization process are monitored using DNP enhanced H-1 -{\textgreater}
    C-13 CP MAS NMR, quantitative F-19 MAS NMR, TGA and ICP-OES analysis, confirming
    the success of the immobilization as well as the stability of bonds between the
    used linker molecule and the cellulose material. Finally, the evaluation of the
    produced catalyst is demonstrated in the asymmetric cyclopropanation reaction
    between styrene and methyl(E)-2-diazo-4-phenylbut-3-enoate showing excellent enantioselectivity
    with an ee of nearly 90% over a wide temperature range as well as good recyclability
    characteristics in four consecutive catalysis cycles.
author:
- first_name: L.
  full_name: Roesler, L.
  last_name: Roesler
- first_name: M. V.
  full_name: Hoefler, M. V.
  last_name: Hoefler
- first_name: H.
  full_name: Breitzke, H.
  last_name: Breitzke
- first_name: T.
  full_name: Wissel, T.
  last_name: Wissel
- first_name: K.
  full_name: Herr, K.
  last_name: Herr
- first_name: H.
  full_name: Heise, H.
  last_name: Heise
- first_name: Torsten
  full_name: Gutmann, Torsten
  id: '118165'
  last_name: Gutmann
- first_name: G.
  full_name: Buntkowsky, G.
  last_name: Buntkowsky
citation:
  ama: Roesler L, Hoefler MV, Breitzke H, et al. Dirhodium complex immobilization
    on modified cellulose for highly selective heterogeneous cyclopropanation reactions.
    <i>Cellulose</i>. 2022;29(11):6283–6299. doi:<a href="https://doi.org/10.1007/s10570-022-04654-y">10.1007/s10570-022-04654-y</a>
  apa: Roesler, L., Hoefler, M. V., Breitzke, H., Wissel, T., Herr, K., Heise, H.,
    Gutmann, T., &#38; Buntkowsky, G. (2022). Dirhodium complex immobilization on
    modified cellulose for highly selective heterogeneous cyclopropanation reactions.
    <i>Cellulose</i>, <i>29</i>(11), 6283–6299. <a href="https://doi.org/10.1007/s10570-022-04654-y">https://doi.org/10.1007/s10570-022-04654-y</a>
  bibtex: '@article{Roesler_Hoefler_Breitzke_Wissel_Herr_Heise_Gutmann_Buntkowsky_2022,
    title={Dirhodium complex immobilization on modified cellulose for highly selective
    heterogeneous cyclopropanation reactions}, volume={29}, DOI={<a href="https://doi.org/10.1007/s10570-022-04654-y">10.1007/s10570-022-04654-y</a>},
    number={11}, journal={Cellulose}, author={Roesler, L. and Hoefler, M. V. and Breitzke,
    H. and Wissel, T. and Herr, K. and Heise, H. and Gutmann, Torsten and Buntkowsky,
    G.}, year={2022}, pages={6283–6299} }'
  chicago: 'Roesler, L., M. V. Hoefler, H. Breitzke, T. Wissel, K. Herr, H. Heise,
    Torsten Gutmann, and G. Buntkowsky. “Dirhodium Complex Immobilization on Modified
    Cellulose for Highly Selective Heterogeneous Cyclopropanation Reactions.” <i>Cellulose</i>
    29, no. 11 (2022): 6283–6299. <a href="https://doi.org/10.1007/s10570-022-04654-y">https://doi.org/10.1007/s10570-022-04654-y</a>.'
  ieee: 'L. Roesler <i>et al.</i>, “Dirhodium complex immobilization on modified cellulose
    for highly selective heterogeneous cyclopropanation reactions,” <i>Cellulose</i>,
    vol. 29, no. 11, pp. 6283–6299, 2022, doi: <a href="https://doi.org/10.1007/s10570-022-04654-y">10.1007/s10570-022-04654-y</a>.'
  mla: Roesler, L., et al. “Dirhodium Complex Immobilization on Modified Cellulose
    for Highly Selective Heterogeneous Cyclopropanation Reactions.” <i>Cellulose</i>,
    vol. 29, no. 11, 2022, pp. 6283–6299, doi:<a href="https://doi.org/10.1007/s10570-022-04654-y">10.1007/s10570-022-04654-y</a>.
  short: L. Roesler, M.V. Hoefler, H. Breitzke, T. Wissel, K. Herr, H. Heise, T. Gutmann,
    G. Buntkowsky, Cellulose 29 (2022) 6283–6299.
date_created: 2026-02-07T16:06:07Z
date_updated: 2026-02-17T16:13:54Z
doi: 10.1007/s10570-022-04654-y
extern: '1'
intvolume: '        29'
issue: '11'
language:
- iso: eng
page: 6283–6299
publication: Cellulose
publication_identifier:
  issn:
  - 0969-0239
status: public
title: Dirhodium complex immobilization on modified cellulose for highly selective
  heterogeneous cyclopropanation reactions
type: journal_article
user_id: '100715'
volume: 29
year: '2022'
...
---
_id: '63994'
abstract:
- lang: eng
  text: Six cluster salts which consist of hexanuclear cluster anions [Nb6Cl12iX6a]2â€“
    (X = Cl or Br) and protonated crown ether molecules (15-crown-5 (15cr5) and 12-crown-4
    (12cr4)) or crown ether-stabilized oxonium cations as well as one compound consisting
    of neutral cluster units, [Nb6Cl16(H2O)2]Â·4 dioxane, were synthesized in good
    to high yields. The single-crystal X-ray structures of six of these compounds
    were determined. The cation/anion ratios and the bond distances confirm in all
    cases oxidized cluster cores with 14 cluster-based electrons. The cations of the
    cluster salts are either sandwich-type dimers of the formula [(15cr5)H]22+ or
    [(15cr5)(H3O)]22+ with the protons or oxonium ions embedded in between the crown
    ether rings or monomeric units in the case of [(12cr4)H]+. 1H NMR investigations
    show that the cluster salts are strong BrÃ¸nsted acids. The fact that the cluster
    core of [Nb6Cl16(H2O)2]Â·4 dioxane is oxidized but still carries water ligands
    indicates that within the multi-step reaction sequence of the formation of the
    cluster-supported acids, the oxidation step happens much faster than the ligand
    exchange steps. Temperature-dependent 2H MAS NMR spectra of deuterium-exchanged
    [(15cr5)H]2[Nb6Cl18]Â·2 CHCl3 are indicative of dynamic processes of the hydrogen-bonded
    protons within the crown ether molecule. Six cluster salts which consist of hexanuclear
    cluster anions [Nb6Cl12iX6a]2â€“ (X = Cl or Br) and protonated crown ether molecules
    (15-crown-5 (15cr5) and 12-crown-4 (12cr4)) or crown ether-stabilized oxonium
    cations as well as one compound consisting of neutral cluster units, [Nb6Cl16(H2O)2]Â·4
    dioxane, were synthesized in good to high yields. The single-crystal X-ray structures
    of six of these compounds were determined. The cation/anion ratios and the bond
    distances confirm in all cases oxidized cluster cores with 14 cluster-based electrons.
    The cations of the cluster salts are either sandwich-type dimers of the formula
    [(15cr5)H]22+ or [(15cr5)(H3O)]22+ with the protons or oxonium ions embedded in
    between the crown ether rings or monomeric units in the case of [(12cr4)H]+. 1H
    NMR investigations show that the cluster salts are strong BrÃ¸nsted acids. The
    fact that the cluster core of [Nb6Cl16(H2O)2]Â·4 dioxane is oxidized but still
    carries water ligands indicates that within the multi-step reaction sequence of
    the formation of the cluster-supported acids, the oxidation step happens much
    faster than the ligand exchange steps. Temperature-dependent 2H MAS NMR spectra
    of deuterium-exchanged [(15cr5)H]2[Nb6Cl18]Â·2 CHCl3 are indicative of dynamic
    processes of the hydrogen-bonded protons within the crown ether molecule.
author:
- first_name: Jonas
  full_name: Koenig, Jonas
  last_name: Koenig
- first_name: Torsten
  full_name: Gutmann, Torsten
  id: '118165'
  last_name: Gutmann
- first_name: Gerd
  full_name: Buntkowsky, Gerd
  last_name: Buntkowsky
- first_name: Martin
  full_name: Koeckerling, Martin
  last_name: Koeckerling
citation:
  ama: 'Koenig J, Gutmann T, Buntkowsky G, Koeckerling M. Strong Cluster-Supported
    BrÃ¸nsted Acids: Hexanuclear Niobium Cluster Compounds with Protonated Crown Ether
    Cations: (Crown-H)2[Nb6Cl12iX6a] (X = Cl or Br) and the Intermediate [Nb6Cl16(H2O)2]Â·4
    dioxane. <i>Inorganic Chemistry</i>. 2022;61(40):15983–15990.'
  apa: 'Koenig, J., Gutmann, T., Buntkowsky, G., &#38; Koeckerling, M. (2022). Strong
    Cluster-Supported BrÃ¸nsted Acids: Hexanuclear Niobium Cluster Compounds with
    Protonated Crown Ether Cations: (Crown-H)2[Nb6Cl12iX6a] (X = Cl or Br) and the
    Intermediate [Nb6Cl16(H2O)2]Â·4 dioxane. <i>Inorganic Chemistry</i>, <i>61</i>(40),
    15983–15990.'
  bibtex: '@article{Koenig_Gutmann_Buntkowsky_Koeckerling_2022, title={Strong Cluster-Supported
    BrÃ¸nsted Acids: Hexanuclear Niobium Cluster Compounds with Protonated Crown Ether
    Cations: (Crown-H)2[Nb6Cl12iX6a] (X = Cl or Br) and the Intermediate [Nb6Cl16(H2O)2]Â·4
    dioxane}, volume={61}, number={40}, journal={Inorganic Chemistry}, publisher={American
    Chemical Society}, author={Koenig, Jonas and Gutmann, Torsten and Buntkowsky,
    Gerd and Koeckerling, Martin}, year={2022}, pages={15983–15990} }'
  chicago: 'Koenig, Jonas, Torsten Gutmann, Gerd Buntkowsky, and Martin Koeckerling.
    “Strong Cluster-Supported BrÃ¸nsted Acids: Hexanuclear Niobium Cluster Compounds
    with Protonated Crown Ether Cations: (Crown-H)2[Nb6Cl12iX6a] (X = Cl or Br) and
    the Intermediate [Nb6Cl16(H2O)2]Â·4 Dioxane.” <i>Inorganic Chemistry</i> 61, no.
    40 (2022): 15983–15990.'
  ieee: 'J. Koenig, T. Gutmann, G. Buntkowsky, and M. Koeckerling, “Strong Cluster-Supported
    BrÃ¸nsted Acids: Hexanuclear Niobium Cluster Compounds with Protonated Crown Ether
    Cations: (Crown-H)2[Nb6Cl12iX6a] (X = Cl or Br) and the Intermediate [Nb6Cl16(H2O)2]Â·4
    dioxane,” <i>Inorganic Chemistry</i>, vol. 61, no. 40, pp. 15983–15990, 2022.'
  mla: 'Koenig, Jonas, et al. “Strong Cluster-Supported BrÃ¸nsted Acids: Hexanuclear
    Niobium Cluster Compounds with Protonated Crown Ether Cations: (Crown-H)2[Nb6Cl12iX6a]
    (X = Cl or Br) and the Intermediate [Nb6Cl16(H2O)2]Â·4 Dioxane.” <i>Inorganic
    Chemistry</i>, vol. 61, no. 40, American Chemical Society, 2022, pp. 15983–15990.'
  short: J. Koenig, T. Gutmann, G. Buntkowsky, M. Koeckerling, Inorganic Chemistry
    61 (2022) 15983–15990.
date_created: 2026-02-07T15:48:14Z
date_updated: 2026-02-17T16:16:07Z
extern: '1'
intvolume: '        61'
issue: '40'
language:
- iso: eng
page: 15983–15990
publication: Inorganic Chemistry
publisher: American Chemical Society
status: public
title: 'Strong Cluster-Supported BrÃ¸nsted Acids: Hexanuclear Niobium Cluster Compounds
  with Protonated Crown Ether Cations: (Crown-H)2[Nb6Cl12iX6a] (X = Cl or Br) and
  the Intermediate [Nb6Cl16(H2O)2]Â·4 dioxane'
type: journal_article
user_id: '100715'
volume: 61
year: '2022'
...
---
_id: '63997'
abstract:
- lang: eng
  text: Abstract Herein we report the mechanochemical Friedel-Crafts alkylation of
    1,3,5-triphenylbenzene (TPB) with two organochloride cross-linking agents, dichloromethane
    (DCM) and chloroform (CHCl3), respectively. During a thorough milling parameter
    evaluation, the DCM-linked polymers were found to be flexible and extremely sensitive
    toward parameter changes, which even enables the synthesis of a polymer with a
    SSABET of 1670 m2/g, on par with the solution-based reference. Contrary, CHCl3-linked
    polymers are exhibiting a rigid structure, with a high porosity that is widely
    unaffected by parameter changes. As a result, a polymer with a SSABET of 1280
    m2/g could be generated in as little as 30 minutes, outperforming the reported
    literature analogue in terms of synthesis time and SSABET. To underline the environmental
    benefits of our fast and solvent-free synthesis approach, the green metrics are
    discussed, revealing an enhancement of the mass intensity, mass productivity and
    the E-factor, as well as of synthesis time and the work-up in comparison to the
    classical synthesis. Therefore, the mechanochemical polymerization is presented
    as a versatile tool, enabling the generation of highly porous polymers within
    short reaction times, with a minimal use of chlorinated cross-linker and with
    the possibility of a post polymerization modification.
author:
- first_name: Annika
  full_name: Krusenbaum, Annika
  last_name: Krusenbaum
- first_name: Jonathan
  full_name: Geisler, Jonathan
  last_name: Geisler
- first_name: Fabien Joel Leon
  full_name: Kraus, Fabien Joel Leon
  last_name: Kraus
- first_name: Sven
  full_name: Grätz, Sven
  last_name: Grätz
- first_name: Mark Valentin
  full_name: Höfler, Mark Valentin
  last_name: Höfler
- first_name: Torsten
  full_name: Gutmann, Torsten
  id: '118165'
  last_name: Gutmann
- first_name: Lars
  full_name: Borchardt, Lars
  last_name: Borchardt
citation:
  ama: Krusenbaum A, Geisler J, Kraus FJL, et al. The mechanochemical Friedel-Crafts
    polymerization as a solvent-free cross-linking approach toward microporous polymers.
    <i>Journal of Polymer Science</i>. 2022;60(1):62–71. doi:<a href="https://doi.org/10.1002/pol.20210606">10.1002/pol.20210606</a>
  apa: Krusenbaum, A., Geisler, J., Kraus, F. J. L., Grätz, S., Höfler, M. V., Gutmann,
    T., &#38; Borchardt, L. (2022). The mechanochemical Friedel-Crafts polymerization
    as a solvent-free cross-linking approach toward microporous polymers. <i>Journal
    of Polymer Science</i>, <i>60</i>(1), 62–71. <a href="https://doi.org/10.1002/pol.20210606">https://doi.org/10.1002/pol.20210606</a>
  bibtex: '@article{Krusenbaum_Geisler_Kraus_Grätz_Höfler_Gutmann_Borchardt_2022,
    title={The mechanochemical Friedel-Crafts polymerization as a solvent-free cross-linking
    approach toward microporous polymers}, volume={60}, DOI={<a href="https://doi.org/10.1002/pol.20210606">10.1002/pol.20210606</a>},
    number={1}, journal={Journal of Polymer Science}, author={Krusenbaum, Annika and
    Geisler, Jonathan and Kraus, Fabien Joel Leon and Grätz, Sven and Höfler, Mark
    Valentin and Gutmann, Torsten and Borchardt, Lars}, year={2022}, pages={62–71}
    }'
  chicago: 'Krusenbaum, Annika, Jonathan Geisler, Fabien Joel Leon Kraus, Sven Grätz,
    Mark Valentin Höfler, Torsten Gutmann, and Lars Borchardt. “The Mechanochemical
    Friedel-Crafts Polymerization as a Solvent-Free Cross-Linking Approach toward
    Microporous Polymers.” <i>Journal of Polymer Science</i> 60, no. 1 (2022): 62–71.
    <a href="https://doi.org/10.1002/pol.20210606">https://doi.org/10.1002/pol.20210606</a>.'
  ieee: 'A. Krusenbaum <i>et al.</i>, “The mechanochemical Friedel-Crafts polymerization
    as a solvent-free cross-linking approach toward microporous polymers,” <i>Journal
    of Polymer Science</i>, vol. 60, no. 1, pp. 62–71, 2022, doi: <a href="https://doi.org/10.1002/pol.20210606">10.1002/pol.20210606</a>.'
  mla: Krusenbaum, Annika, et al. “The Mechanochemical Friedel-Crafts Polymerization
    as a Solvent-Free Cross-Linking Approach toward Microporous Polymers.” <i>Journal
    of Polymer Science</i>, vol. 60, no. 1, 2022, pp. 62–71, doi:<a href="https://doi.org/10.1002/pol.20210606">10.1002/pol.20210606</a>.
  short: A. Krusenbaum, J. Geisler, F.J.L. Kraus, S. Grätz, M.V. Höfler, T. Gutmann,
    L. Borchardt, Journal of Polymer Science 60 (2022) 62–71.
date_created: 2026-02-07T15:50:44Z
date_updated: 2026-02-17T16:16:01Z
doi: 10.1002/pol.20210606
extern: '1'
intvolume: '        60'
issue: '1'
language:
- iso: eng
page: 62–71
publication: Journal of Polymer Science
status: public
title: The mechanochemical Friedel-Crafts polymerization as a solvent-free cross-linking
  approach toward microporous polymers
type: journal_article
user_id: '100715'
volume: 60
year: '2022'
...
---
_id: '63983'
abstract:
- lang: eng
  text: Polyethylene glycol (PEG) is increasingly used as an alternative green chemical
    solvent. New experimental measurements on density, viscosity, and self-diffusion
    coefficient are presented for PEG200, PEG400, and several binary mixtures of tri-
    and hexaethylene glycol covering a temperature range from 298.15 to 358.15 K.
    Because PEGs are polydisperse, the exact compositions of PEG200 from six different
    vendors are analytically determined and found to be comparable. Thus, only two
    of the most differing PEG200 samples are further examined. The effects of water
    as the most common impurity on densities, viscosities, and self-diffusion coefficients
    are inspected as well as the results of the “dry” samples obtained by extrapolation
    to zero water content. The obtained results are carefully compared to the available
    literature data. The temperature dependence of these physical properties is investigated
    and found to be linear for density, while viscosity and self-diffusion coefficients
    follow the Arrhenius law. Attempts to calculate the properties of the binary mixtures
    and PEG200 samples from the mole fraction weighted average of the physical properties
    of the mixture components result in reasonable agreement. Agreement between calculated
    and measured molar volumes is within measurement uncertainty. Agreement of calculated
    and measured viscosities is mostly within a few percent but increases with decreasing
    temperature (largest viscosities) reaching values of up to 15%. Similarly, calculated
    and measured self-diffusion coefficients mostly agree within 20%, which is near
    the measurement uncertainty, but overestimates increase to 30% for the highest
    temperatures (largest self-diffusion coefficients).
author:
- first_name: Markus M.
  full_name: Hoffmann, Markus M.
  last_name: Hoffmann
- first_name: Joseph D.
  full_name: Kealy, Joseph D.
  last_name: Kealy
- first_name: Torsten
  full_name: Gutmann, Torsten
  id: '118165'
  last_name: Gutmann
- first_name: Gerd
  full_name: Buntkowsky, Gerd
  last_name: Buntkowsky
citation:
  ama: Hoffmann MM, Kealy JD, Gutmann T, Buntkowsky G. Densities, Viscosities, and
    Self-Diffusion Coefficients of Several Polyethylene Glycols. <i>Journal of Chemical
    and Engineering Data</i>. 2022;67(1):88–103. doi:<a href="https://doi.org/10.1021/acs.jced.1c00759">10.1021/acs.jced.1c00759</a>
  apa: Hoffmann, M. M., Kealy, J. D., Gutmann, T., &#38; Buntkowsky, G. (2022). Densities,
    Viscosities, and Self-Diffusion Coefficients of Several Polyethylene Glycols.
    <i>Journal of Chemical and Engineering Data</i>, <i>67</i>(1), 88–103. <a href="https://doi.org/10.1021/acs.jced.1c00759">https://doi.org/10.1021/acs.jced.1c00759</a>
  bibtex: '@article{Hoffmann_Kealy_Gutmann_Buntkowsky_2022, title={Densities, Viscosities,
    and Self-Diffusion Coefficients of Several Polyethylene Glycols}, volume={67},
    DOI={<a href="https://doi.org/10.1021/acs.jced.1c00759">10.1021/acs.jced.1c00759</a>},
    number={1}, journal={Journal of Chemical and Engineering Data}, publisher={American
    Chemical Society}, author={Hoffmann, Markus M. and Kealy, Joseph D. and Gutmann,
    Torsten and Buntkowsky, Gerd}, year={2022}, pages={88–103} }'
  chicago: 'Hoffmann, Markus M., Joseph D. Kealy, Torsten Gutmann, and Gerd Buntkowsky.
    “Densities, Viscosities, and Self-Diffusion Coefficients of Several Polyethylene
    Glycols.” <i>Journal of Chemical and Engineering Data</i> 67, no. 1 (2022): 88–103.
    <a href="https://doi.org/10.1021/acs.jced.1c00759">https://doi.org/10.1021/acs.jced.1c00759</a>.'
  ieee: 'M. M. Hoffmann, J. D. Kealy, T. Gutmann, and G. Buntkowsky, “Densities, Viscosities,
    and Self-Diffusion Coefficients of Several Polyethylene Glycols,” <i>Journal of
    Chemical and Engineering Data</i>, vol. 67, no. 1, pp. 88–103, 2022, doi: <a href="https://doi.org/10.1021/acs.jced.1c00759">10.1021/acs.jced.1c00759</a>.'
  mla: Hoffmann, Markus M., et al. “Densities, Viscosities, and Self-Diffusion Coefficients
    of Several Polyethylene Glycols.” <i>Journal of Chemical and Engineering Data</i>,
    vol. 67, no. 1, American Chemical Society, 2022, pp. 88–103, doi:<a href="https://doi.org/10.1021/acs.jced.1c00759">10.1021/acs.jced.1c00759</a>.
  short: M.M. Hoffmann, J.D. Kealy, T. Gutmann, G. Buntkowsky, Journal of Chemical
    and Engineering Data 67 (2022) 88–103.
date_created: 2026-02-07T15:44:52Z
date_updated: 2026-02-17T16:16:54Z
doi: 10.1021/acs.jced.1c00759
extern: '1'
intvolume: '        67'
issue: '1'
language:
- iso: eng
page: 88–103
publication: Journal of Chemical and Engineering Data
publisher: American Chemical Society
status: public
title: Densities, Viscosities, and Self-Diffusion Coefficients of Several Polyethylene
  Glycols
type: journal_article
user_id: '100715'
volume: 67
year: '2022'
...
---
_id: '63948'
abstract:
- lang: eng
  text: In this work, the behavior of four different commercially available polarizing
    agents is investigated employing the non-ionic model surfactant 1-octanol as analyte.
    A relative method for the comparison of the proportion of the direct and indirect
    polarization transfer pathways is established, allowing a direct comparison of
    the polarization efficacy for different radicals and different parts of the 1-octanol
    molecule despite differences in radical concentration or sample amount. With this
    approach, it could be demonstrated that the hydrophilicity is a key factor in
    the way polarization is transferred from the polarizing agent to the analyte.
    These findings are confirmed by the determination of buildup times Tb, illustrating
    that the choice of polarizing agent plays an essential role in ensuring an optimal
    polarization transfer and therefore the maximum amount of enhancement possible
    for DNP enhanced NMR measurements.
author:
- first_name: Sonja C.
  full_name: Döller, Sonja C.
  last_name: Döller
- first_name: Torsten
  full_name: Gutmann, Torsten
  id: '118165'
  last_name: Gutmann
- first_name: Markus
  full_name: Hoffmann, Markus
  last_name: Hoffmann
- first_name: Gerd
  full_name: Buntkowsky, Gerd
  last_name: Buntkowsky
citation:
  ama: Döller SC, Gutmann T, Hoffmann M, Buntkowsky G. A case study on the influence
    of hydrophilicity on the signal enhancement by dynamic nuclear polarization. <i>Solid
    State Nuclear Magnetic Resonance</i>. 2022;122:101829.
  apa: Döller, S. C., Gutmann, T., Hoffmann, M., &#38; Buntkowsky, G. (2022). A case
    study on the influence of hydrophilicity on the signal enhancement by dynamic
    nuclear polarization. <i>Solid State Nuclear Magnetic Resonance</i>, <i>122</i>,
    101829.
  bibtex: '@article{Döller_Gutmann_Hoffmann_Buntkowsky_2022, title={A case study on
    the influence of hydrophilicity on the signal enhancement by dynamic nuclear polarization},
    volume={122}, journal={Solid State Nuclear Magnetic Resonance}, author={Döller,
    Sonja C. and Gutmann, Torsten and Hoffmann, Markus and Buntkowsky, Gerd}, year={2022},
    pages={101829} }'
  chicago: 'Döller, Sonja C., Torsten Gutmann, Markus Hoffmann, and Gerd Buntkowsky.
    “A Case Study on the Influence of Hydrophilicity on the Signal Enhancement by
    Dynamic Nuclear Polarization.” <i>Solid State Nuclear Magnetic Resonance</i> 122
    (2022): 101829.'
  ieee: S. C. Döller, T. Gutmann, M. Hoffmann, and G. Buntkowsky, “A case study on
    the influence of hydrophilicity on the signal enhancement by dynamic nuclear polarization,”
    <i>Solid State Nuclear Magnetic Resonance</i>, vol. 122, p. 101829, 2022.
  mla: Döller, Sonja C., et al. “A Case Study on the Influence of Hydrophilicity on
    the Signal Enhancement by Dynamic Nuclear Polarization.” <i>Solid State Nuclear
    Magnetic Resonance</i>, vol. 122, 2022, p. 101829.
  short: S.C. Döller, T. Gutmann, M. Hoffmann, G. Buntkowsky, Solid State Nuclear
    Magnetic Resonance 122 (2022) 101829.
date_created: 2026-02-07T09:13:08Z
date_updated: 2026-02-17T16:18:26Z
extern: '1'
intvolume: '       122'
keyword:
- DNP NMR
- Dynamics
- Low temperature NMR
- Octanol
- Solid state NMR
- Surfactants
language:
- iso: eng
page: '101829'
publication: Solid State Nuclear Magnetic Resonance
status: public
title: A case study on the influence of hydrophilicity on the signal enhancement by
  dynamic nuclear polarization
type: journal_article
user_id: '100715'
volume: 122
year: '2022'
...
---
_id: '63944'
abstract:
- lang: eng
  text: Abstract The donor properties of a set of bulky ferrocene based bisphosphanes
    (Fe(C5H4PMes2)2 and (C5H4PMes2)Fe(C5H4PtBu2 with Mes= mesityl and tBu=tert-butyl)
    were probed by exploring the NMR parameters of the corresponding selenophosphoranes
    amended by cyclovoltammetry. The ligand properties were explored in the complexation
    of copper phenylacetylide which is relevant as intermediate in the Cu(I) catalyzed
    CO2 addition to phenylacetylene. Owing to the poor solubility of the resulting
    complexes their characterization was performed with solid state NMR spectroscopy
    amended by IR spectroscopy, mass spectrometry and elemental analysis. Remarkably,
    these complexes feature luminescent properties, albeit with limited quantum yield.
author:
- first_name: Subhayan
  full_name: Dey, Subhayan
  last_name: Dey
- first_name: Fabian
  full_name: Roesler, Fabian
  last_name: Roesler
- first_name: Mark V.
  full_name: Höfler, Mark V.
  last_name: Höfler
- first_name: Clemens
  full_name: Bruhn, Clemens
  last_name: Bruhn
- first_name: Torsten
  full_name: Gutmann, Torsten
  id: '118165'
  last_name: Gutmann
- first_name: Rudolf
  full_name: Pietschnig, Rudolf
  last_name: Pietschnig
citation:
  ama: Dey S, Roesler F, Höfler MV, Bruhn C, Gutmann T, Pietschnig R. Synthesis, Structure
    and Cu-Phenylacetylide Coordination of an Unsymmetrically Substituted Bulky dppf-Analog.
    <i>European Journal of Inorganic Chemistry</i>. 2022;2022(3):e202100939. doi:<a
    href="https://doi.org/10.1002/ejic.202100939">10.1002/ejic.202100939</a>
  apa: Dey, S., Roesler, F., Höfler, M. V., Bruhn, C., Gutmann, T., &#38; Pietschnig,
    R. (2022). Synthesis, Structure and Cu-Phenylacetylide Coordination of an Unsymmetrically
    Substituted Bulky dppf-Analog. <i>European Journal of Inorganic Chemistry</i>,
    <i>2022</i>(3), e202100939. <a href="https://doi.org/10.1002/ejic.202100939">https://doi.org/10.1002/ejic.202100939</a>
  bibtex: '@article{Dey_Roesler_Höfler_Bruhn_Gutmann_Pietschnig_2022, title={Synthesis,
    Structure and Cu-Phenylacetylide Coordination of an Unsymmetrically Substituted
    Bulky dppf-Analog}, volume={2022}, DOI={<a href="https://doi.org/10.1002/ejic.202100939">10.1002/ejic.202100939</a>},
    number={3}, journal={European Journal of Inorganic Chemistry}, author={Dey, Subhayan
    and Roesler, Fabian and Höfler, Mark V. and Bruhn, Clemens and Gutmann, Torsten
    and Pietschnig, Rudolf}, year={2022}, pages={e202100939} }'
  chicago: 'Dey, Subhayan, Fabian Roesler, Mark V. Höfler, Clemens Bruhn, Torsten
    Gutmann, and Rudolf Pietschnig. “Synthesis, Structure and Cu-Phenylacetylide Coordination
    of an Unsymmetrically Substituted Bulky Dppf-Analog.” <i>European Journal of Inorganic
    Chemistry</i> 2022, no. 3 (2022): e202100939. <a href="https://doi.org/10.1002/ejic.202100939">https://doi.org/10.1002/ejic.202100939</a>.'
  ieee: 'S. Dey, F. Roesler, M. V. Höfler, C. Bruhn, T. Gutmann, and R. Pietschnig,
    “Synthesis, Structure and Cu-Phenylacetylide Coordination of an Unsymmetrically
    Substituted Bulky dppf-Analog,” <i>European Journal of Inorganic Chemistry</i>,
    vol. 2022, no. 3, p. e202100939, 2022, doi: <a href="https://doi.org/10.1002/ejic.202100939">10.1002/ejic.202100939</a>.'
  mla: Dey, Subhayan, et al. “Synthesis, Structure and Cu-Phenylacetylide Coordination
    of an Unsymmetrically Substituted Bulky Dppf-Analog.” <i>European Journal of Inorganic
    Chemistry</i>, vol. 2022, no. 3, 2022, p. e202100939, doi:<a href="https://doi.org/10.1002/ejic.202100939">10.1002/ejic.202100939</a>.
  short: S. Dey, F. Roesler, M.V. Höfler, C. Bruhn, T. Gutmann, R. Pietschnig, European
    Journal of Inorganic Chemistry 2022 (2022) e202100939.
date_created: 2026-02-07T09:11:00Z
date_updated: 2026-02-17T16:18:34Z
doi: 10.1002/ejic.202100939
extern: '1'
intvolume: '      2022'
issue: '3'
language:
- iso: eng
page: e202100939
publication: European Journal of Inorganic Chemistry
status: public
title: Synthesis, Structure and Cu-Phenylacetylide Coordination of an Unsymmetrically
  Substituted Bulky dppf-Analog
type: journal_article
user_id: '100715'
volume: 2022
year: '2022'
...
