--- _id: '63962' author: - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: Bharti full_name: Kumari, Bharti last_name: Kumari - first_name: Li full_name: Zhao, Li last_name: Zhao - first_name: Hergen full_name: Breitzke, Hergen last_name: Breitzke - first_name: Sebastian full_name: Schöttner, Sebastian last_name: Schöttner - first_name: Christian full_name: Rüttiger, Christian last_name: Rüttiger - first_name: Markus full_name: Gallei, Markus last_name: Gallei citation: ama: Gutmann T, Kumari B, Zhao L, et al. Dynamic Nuclear Polarization Signal Amplification as a Sensitive Probe for Specific Functionalization of Complex Paper Substrates. Journal of Physical Chemistry C. 2017;121(7):3896–3903. doi:10.1021/acs.jpcc.6b11751 apa: Gutmann, T., Kumari, B., Zhao, L., Breitzke, H., Schöttner, S., Rüttiger, C., & Gallei, M. (2017). Dynamic Nuclear Polarization Signal Amplification as a Sensitive Probe for Specific Functionalization of Complex Paper Substrates. Journal of Physical Chemistry C, 121(7), 3896–3903. https://doi.org/10.1021/acs.jpcc.6b11751 bibtex: '@article{Gutmann_Kumari_Zhao_Breitzke_Schöttner_Rüttiger_Gallei_2017, title={Dynamic Nuclear Polarization Signal Amplification as a Sensitive Probe for Specific Functionalization of Complex Paper Substrates}, volume={121}, DOI={10.1021/acs.jpcc.6b11751}, number={7}, journal={Journal of Physical Chemistry C}, publisher={American Chemical Society}, author={Gutmann, Torsten and Kumari, Bharti and Zhao, Li and Breitzke, Hergen and Schöttner, Sebastian and Rüttiger, Christian and Gallei, Markus}, year={2017}, pages={3896–3903} }' chicago: 'Gutmann, Torsten, Bharti Kumari, Li Zhao, Hergen Breitzke, Sebastian Schöttner, Christian Rüttiger, and Markus Gallei. “Dynamic Nuclear Polarization Signal Amplification as a Sensitive Probe for Specific Functionalization of Complex Paper Substrates.” Journal of Physical Chemistry C 121, no. 7 (2017): 3896–3903. https://doi.org/10.1021/acs.jpcc.6b11751.' ieee: 'T. Gutmann et al., “Dynamic Nuclear Polarization Signal Amplification as a Sensitive Probe for Specific Functionalization of Complex Paper Substrates,” Journal of Physical Chemistry C, vol. 121, no. 7, pp. 3896–3903, 2017, doi: 10.1021/acs.jpcc.6b11751.' mla: Gutmann, Torsten, et al. “Dynamic Nuclear Polarization Signal Amplification as a Sensitive Probe for Specific Functionalization of Complex Paper Substrates.” Journal of Physical Chemistry C, vol. 121, no. 7, American Chemical Society, 2017, pp. 3896–3903, doi:10.1021/acs.jpcc.6b11751. short: T. Gutmann, B. Kumari, L. Zhao, H. Breitzke, S. Schöttner, C. Rüttiger, M. Gallei, Journal of Physical Chemistry C 121 (2017) 3896–3903. date_created: 2026-02-07T15:37:49Z date_updated: 2026-02-17T16:17:51Z doi: 10.1021/acs.jpcc.6b11751 extern: '1' intvolume: ' 121' issue: '7' language: - iso: eng page: 3896–3903 publication: Journal of Physical Chemistry C publication_identifier: issn: - 1932-7447 publisher: American Chemical Society status: public title: Dynamic Nuclear Polarization Signal Amplification as a Sensitive Probe for Specific Functionalization of Complex Paper Substrates type: journal_article user_id: '100715' volume: 121 year: '2017' ... --- _id: '63956' abstract: - lang: eng text: The synthesis of novel robust and stable iridium-based immobilized catalysts on silica-polymer hybrid materials (Si-PB-Ir) is described. These catalysts are characterized by a combination of 1D P-31 CP-MAS and 2D P-31-H-1 HETCOR and J-resolved multinuclear solid state NMR experiments. Different binding situations such as singly and multiply coordinated phosphines are identified. Density functional theory (DFT) calculations are performed to corroborate the interpretation of the experimental NMR data, in order to propose a structural model of the heterogenized catalysts. Finally, the catalytic activity of the Si-PB-Ir catalysts is investigated for the hydrogenation of styrene employing para-enriched hydrogen gas. author: - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: S. full_name: Alkhagani, S. last_name: Alkhagani - first_name: N. full_name: Rothermel, N. last_name: Rothermel - first_name: H. H. full_name: Limbach, H. H. last_name: Limbach - first_name: H. full_name: Breitzke, H. last_name: Breitzke - first_name: G. full_name: Buntkowsky, G. last_name: Buntkowsky citation: ama: Gutmann T, Alkhagani S, Rothermel N, Limbach HH, Breitzke H, Buntkowsky G. P-31-Solid-State NMR Characterization and Catalytic Hydrogenation Tests of Novel heterogenized Iridium-Catalysts. Zeitschrift Fur Physikalische Chemie-International Journal of Research in Physical Chemistry & Chemical Physics. 2017;231(3):653–669. doi:10.1515/zpch-2016-0837 apa: Gutmann, T., Alkhagani, S., Rothermel, N., Limbach, H. H., Breitzke, H., & Buntkowsky, G. (2017). P-31-Solid-State NMR Characterization and Catalytic Hydrogenation Tests of Novel heterogenized Iridium-Catalysts. Zeitschrift Fur Physikalische Chemie-International Journal of Research in Physical Chemistry & Chemical Physics, 231(3), 653–669. https://doi.org/10.1515/zpch-2016-0837 bibtex: '@article{Gutmann_Alkhagani_Rothermel_Limbach_Breitzke_Buntkowsky_2017, title={P-31-Solid-State NMR Characterization and Catalytic Hydrogenation Tests of Novel heterogenized Iridium-Catalysts}, volume={231}, DOI={10.1515/zpch-2016-0837}, number={3}, journal={Zeitschrift Fur Physikalische Chemie-International Journal of Research in Physical Chemistry & Chemical Physics}, author={Gutmann, Torsten and Alkhagani, S. and Rothermel, N. and Limbach, H. H. and Breitzke, H. and Buntkowsky, G.}, year={2017}, pages={653–669} }' chicago: 'Gutmann, Torsten, S. Alkhagani, N. Rothermel, H. H. Limbach, H. Breitzke, and G. Buntkowsky. “P-31-Solid-State NMR Characterization and Catalytic Hydrogenation Tests of Novel Heterogenized Iridium-Catalysts.” Zeitschrift Fur Physikalische Chemie-International Journal of Research in Physical Chemistry & Chemical Physics 231, no. 3 (2017): 653–669. https://doi.org/10.1515/zpch-2016-0837.' ieee: 'T. Gutmann, S. Alkhagani, N. Rothermel, H. H. Limbach, H. Breitzke, and G. Buntkowsky, “P-31-Solid-State NMR Characterization and Catalytic Hydrogenation Tests of Novel heterogenized Iridium-Catalysts,” Zeitschrift Fur Physikalische Chemie-International Journal of Research in Physical Chemistry & Chemical Physics, vol. 231, no. 3, pp. 653–669, 2017, doi: 10.1515/zpch-2016-0837.' mla: Gutmann, Torsten, et al. “P-31-Solid-State NMR Characterization and Catalytic Hydrogenation Tests of Novel Heterogenized Iridium-Catalysts.” Zeitschrift Fur Physikalische Chemie-International Journal of Research in Physical Chemistry & Chemical Physics, vol. 231, no. 3, 2017, pp. 653–669, doi:10.1515/zpch-2016-0837. short: T. Gutmann, S. Alkhagani, N. Rothermel, H.H. Limbach, H. Breitzke, G. Buntkowsky, Zeitschrift Fur Physikalische Chemie-International Journal of Research in Physical Chemistry & Chemical Physics 231 (2017) 653–669. date_created: 2026-02-07T15:35:41Z date_updated: 2026-02-17T16:18:04Z doi: 10.1515/zpch-2016-0837 extern: '1' intvolume: ' 231' issue: '3' keyword: - Chemistry - dynamic nuclear-polarization - solid-state nmr - DFT - heterogeneous catalysis - hydrido complexes - hydrogenation - immobilized catalyst - inorganic hybrid - iridium - materials - mesoporous - molecular-orbital methods - PHIP - phosphine complexes - reusable catalysts - silica - solid-state-NMR - wilkinsons catalyst language: - iso: eng page: 653–669 publication: Zeitschrift Fur Physikalische Chemie-International Journal of Research in Physical Chemistry & Chemical Physics publication_identifier: issn: - 0942-9352 status: public title: P-31-Solid-State NMR Characterization and Catalytic Hydrogenation Tests of Novel heterogenized Iridium-Catalysts type: journal_article user_id: '100715' volume: 231 year: '2017' ... --- _id: '63958' author: - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: Gerd full_name: Buntkowsky, Gerd last_name: Buntkowsky citation: ama: 'Gutmann T, Buntkowsky G. Solid-state NMR Studies of Supported Transition Metal Catalysts and Nanoparticles. In: Webb GA, ed. Modern Magnetic Resonance. Solid-State NMR Studies of Supported Transition Metal Catalysts and Nanoparticles. Springer International Publishing; 2017:1–21. doi:10.1007/978-3-319-28275-6_39-1' apa: Gutmann, T., & Buntkowsky, G. (2017). Solid-state NMR Studies of Supported Transition Metal Catalysts and Nanoparticles. In G. A. Webb (Ed.), Modern Magnetic Resonance. Solid-state NMR Studies of Supported Transition Metal Catalysts and Nanoparticles (pp. 1–21). Springer International Publishing. https://doi.org/10.1007/978-3-319-28275-6_39-1 bibtex: '@inbook{Gutmann_Buntkowsky_2017, place={Cham}, title={Solid-state NMR Studies of Supported Transition Metal Catalysts and Nanoparticles}, DOI={10.1007/978-3-319-28275-6_39-1}, booktitle={Modern Magnetic Resonance. Solid-state NMR Studies of Supported Transition Metal Catalysts and Nanoparticles}, publisher={Springer International Publishing}, author={Gutmann, Torsten and Buntkowsky, Gerd}, editor={Webb, Graham A.}, year={2017}, pages={1–21} }' chicago: 'Gutmann, Torsten, and Gerd Buntkowsky. “Solid-State NMR Studies of Supported Transition Metal Catalysts and Nanoparticles.” In Modern Magnetic Resonance. Solid-State NMR Studies of Supported Transition Metal Catalysts and Nanoparticles, edited by Graham A. Webb, 1–21. Cham: Springer International Publishing, 2017. https://doi.org/10.1007/978-3-319-28275-6_39-1.' ieee: 'T. Gutmann and G. Buntkowsky, “Solid-state NMR Studies of Supported Transition Metal Catalysts and Nanoparticles,” in Modern Magnetic Resonance. Solid-state NMR Studies of Supported Transition Metal Catalysts and Nanoparticles, G. A. Webb, Ed. Cham: Springer International Publishing, 2017, pp. 1–21.' mla: Gutmann, Torsten, and Gerd Buntkowsky. “Solid-State NMR Studies of Supported Transition Metal Catalysts and Nanoparticles.” Modern Magnetic Resonance. Solid-State NMR Studies of Supported Transition Metal Catalysts and Nanoparticles, edited by Graham A. Webb, Springer International Publishing, 2017, pp. 1–21, doi:10.1007/978-3-319-28275-6_39-1. short: 'T. Gutmann, G. Buntkowsky, in: G.A. Webb (Ed.), Modern Magnetic Resonance. Solid-State NMR Studies of Supported Transition Metal Catalysts and Nanoparticles, Springer International Publishing, Cham, 2017, pp. 1–21.' date_created: 2026-02-07T15:36:23Z date_updated: 2026-02-17T16:18:00Z doi: 10.1007/978-3-319-28275-6_39-1 editor: - first_name: Graham A. full_name: Webb, Graham A. last_name: Webb extern: '1' language: - iso: eng page: 1–21 place: Cham publication: Modern Magnetic Resonance. Solid-state NMR Studies of Supported Transition Metal Catalysts and Nanoparticles publication_identifier: isbn: - 978-3-319-28275-6 publisher: Springer International Publishing status: public title: Solid-state NMR Studies of Supported Transition Metal Catalysts and Nanoparticles type: book_chapter user_id: '100715' year: '2017' ... --- _id: '63949' abstract: - lang: eng text: In paper-based devices, capillary fluid flow is based on length-scale selective functional control within a hierarchical porous system. The fluid flow can be tuned by altering the paper preparation process, which controls parameters such as the paper grammage. Interestingly, the fiber morphology and nanoporosity are often neglected. In this work, porous voids are incorporated into paper by the combination of dense or mesoporous ceramic silica coatings with hierarchically porous cotton linter paper. Varying the silica coating leads to significant changes in the fluid flow characteristics, up to the complete water exclusion without any further fiber surface hydrophobization, providing new approaches to control fluid flow. Additionally, functionalization with redox-responsive polymers leads to reversible, dynamic gating of fluid flow in these hybrid paper materials, demonstrating the potential of length scale specific, dynamic, and external transport control. author: - first_name: C. full_name: Dubois, C. last_name: Dubois - first_name: N. full_name: Herzog, N. last_name: Herzog - first_name: C. full_name: Ruettiger, C. last_name: Ruettiger - first_name: A. full_name: Geissler, A. last_name: Geissler - first_name: E. full_name: Grange, E. last_name: Grange - first_name: U. full_name: Kunz, U. last_name: Kunz - first_name: H. J. full_name: Kleebe, H. J. last_name: Kleebe - first_name: M. full_name: Biesalski, M. last_name: Biesalski - first_name: T. full_name: Meckel, T. last_name: Meckel - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: M. full_name: Gallei, M. last_name: Gallei - first_name: A. full_name: Andrieu-Brunsen, A. last_name: Andrieu-Brunsen citation: ama: Dubois C, Herzog N, Ruettiger C, et al. Fluid Flow Programming in Paper-Derived Silica-Polymer Hybrids. Langmuir. 2017;33(1):332–339. doi:10.1021/acs.langmuir.6b03839 apa: Dubois, C., Herzog, N., Ruettiger, C., Geissler, A., Grange, E., Kunz, U., Kleebe, H. J., Biesalski, M., Meckel, T., Gutmann, T., Gallei, M., & Andrieu-Brunsen, A. (2017). Fluid Flow Programming in Paper-Derived Silica-Polymer Hybrids. Langmuir, 33(1), 332–339. https://doi.org/10.1021/acs.langmuir.6b03839 bibtex: '@article{Dubois_Herzog_Ruettiger_Geissler_Grange_Kunz_Kleebe_Biesalski_Meckel_Gutmann_et al._2017, title={Fluid Flow Programming in Paper-Derived Silica-Polymer Hybrids}, volume={33}, DOI={10.1021/acs.langmuir.6b03839}, number={1}, journal={Langmuir}, author={Dubois, C. and Herzog, N. and Ruettiger, C. and Geissler, A. and Grange, E. and Kunz, U. and Kleebe, H. J. and Biesalski, M. and Meckel, T. and Gutmann, Torsten and et al.}, year={2017}, pages={332–339} }' chicago: 'Dubois, C., N. Herzog, C. Ruettiger, A. Geissler, E. Grange, U. Kunz, H. J. Kleebe, et al. “Fluid Flow Programming in Paper-Derived Silica-Polymer Hybrids.” Langmuir 33, no. 1 (2017): 332–339. https://doi.org/10.1021/acs.langmuir.6b03839.' ieee: 'C. Dubois et al., “Fluid Flow Programming in Paper-Derived Silica-Polymer Hybrids,” Langmuir, vol. 33, no. 1, pp. 332–339, 2017, doi: 10.1021/acs.langmuir.6b03839.' mla: Dubois, C., et al. “Fluid Flow Programming in Paper-Derived Silica-Polymer Hybrids.” Langmuir, vol. 33, no. 1, 2017, pp. 332–339, doi:10.1021/acs.langmuir.6b03839. short: C. Dubois, N. Herzog, C. Ruettiger, A. Geissler, E. Grange, U. Kunz, H.J. Kleebe, M. Biesalski, T. Meckel, T. Gutmann, M. Gallei, A. Andrieu-Brunsen, Langmuir 33 (2017) 332–339. date_created: 2026-02-07T09:13:29Z date_updated: 2026-02-17T16:18:24Z doi: 10.1021/acs.langmuir.6b03839 extern: '1' intvolume: ' 33' issue: '1' language: - iso: eng page: 332–339 publication: Langmuir publication_identifier: issn: - 0743-7463 status: public title: Fluid Flow Programming in Paper-Derived Silica-Polymer Hybrids type: journal_article user_id: '100715' volume: 33 year: '2017' ... --- _id: '63927' abstract: - lang: eng text: A detailed study of the magnetic field dependent signal enhancement in solid-state dynamic nuclear polarization (DNP) experiments is presented for a specific sample consisting of AMUPol dissolved in the nonionic surfactant C10E6. C10E6 displays a superposition of “direct” and “indirect channel” resonances in 13C MAS DNP NMR spectra. The shapes of the DNP enhancement profiles are essentially identical for the 1H MAS, 1H → 13C CP MAS, and 13C MAS indirect channel signals, which confirms that the same polarization transfer process from electron to proton is responsible for the obtained enhancements of these experiments. The shape of the DNP enhancement profiles of 1H and of 13C direct channel resonances reveals that the cross effect is the dominant polarization transfer mechanism for the studied sample. The magnitudes of the 13C MAS DNP enhancement profiles for 1H → 13C CP MAS, direct and indirect channel signals were found to be not uniform. For 1H → 13C CP MAS and the indirect channel signals, this observation is related to relaxation effects of the methyl group carbon. For the 13C MAS direct channel resonances, differences in magnitudes are discussed in terms of preferential structural orientation of the polar ethylene oxide headgroup of C10E6 toward the AMUPol radical. author: - first_name: Sarah full_name: Bothe, Sarah last_name: Bothe - 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: Bothe S, Hoffmann MM, Gutmann T, Buntkowsky G. Comparative Study of the Magnetic Field Dependent Signal Enhancement in Solid-State Dynamic Nuclear Polarization Experiments. Journal of Physical Chemistry C. 2017;121(48):27089–27097. doi:10.1021/acs.jpcc.7b07967 apa: Bothe, S., Hoffmann, M. M., Gutmann, T., & Buntkowsky, G. (2017). Comparative Study of the Magnetic Field Dependent Signal Enhancement in Solid-State Dynamic Nuclear Polarization Experiments. Journal of Physical Chemistry C, 121(48), 27089–27097. https://doi.org/10.1021/acs.jpcc.7b07967 bibtex: '@article{Bothe_Hoffmann_Gutmann_Buntkowsky_2017, title={Comparative Study of the Magnetic Field Dependent Signal Enhancement in Solid-State Dynamic Nuclear Polarization Experiments}, volume={121}, DOI={10.1021/acs.jpcc.7b07967}, number={48}, journal={Journal of Physical Chemistry C}, publisher={American Chemical Society}, author={Bothe, Sarah and Hoffmann, Markus M. and Gutmann, Torsten and Buntkowsky, Gerd}, year={2017}, pages={27089–27097} }' chicago: 'Bothe, Sarah, Markus M. Hoffmann, Torsten Gutmann, and Gerd Buntkowsky. “Comparative Study of the Magnetic Field Dependent Signal Enhancement in Solid-State Dynamic Nuclear Polarization Experiments.” Journal of Physical Chemistry C 121, no. 48 (2017): 27089–27097. https://doi.org/10.1021/acs.jpcc.7b07967.' ieee: 'S. Bothe, M. M. Hoffmann, T. Gutmann, and G. Buntkowsky, “Comparative Study of the Magnetic Field Dependent Signal Enhancement in Solid-State Dynamic Nuclear Polarization Experiments,” Journal of Physical Chemistry C, vol. 121, no. 48, pp. 27089–27097, 2017, doi: 10.1021/acs.jpcc.7b07967.' mla: Bothe, Sarah, et al. “Comparative Study of the Magnetic Field Dependent Signal Enhancement in Solid-State Dynamic Nuclear Polarization Experiments.” Journal of Physical Chemistry C, vol. 121, no. 48, American Chemical Society, 2017, pp. 27089–27097, doi:10.1021/acs.jpcc.7b07967. short: S. Bothe, M.M. Hoffmann, T. Gutmann, G. Buntkowsky, Journal of Physical Chemistry C 121 (2017) 27089–27097. date_created: 2026-02-07T08:59:47Z date_updated: 2026-02-17T16:19:11Z doi: 10.1021/acs.jpcc.7b07967 extern: '1' intvolume: ' 121' issue: '48' language: - iso: eng page: 27089–27097 publication: Journal of Physical Chemistry C publication_identifier: issn: - 1932-7447 publisher: American Chemical Society status: public title: Comparative Study of the Magnetic Field Dependent Signal Enhancement in Solid-State Dynamic Nuclear Polarization Experiments type: journal_article user_id: '100715' volume: 121 year: '2017' ... --- _id: '63920' abstract: - lang: eng text: Coordinatively unsaturated sites (CUS) present a key feature of alumina based catalysts as they are believed to act as Lewis-acid sites in heterogeneously catalyzed reactions. In the present study, the direct observation of active species on a fluoride-doped aluminum oxide catalyst is demonstrated. This new fluoride-doped aluminum oxide exhibits strong Lewis-acid sites and superior catalytic activity as compared to gamma-Al2O3. To emphasize the labile state of Lewis-acid sites, two distinctive states of the catalysts surface are addressed using H-1-Al-27 cross polarization (CP) MAS NMR. On the one hand, the highly dehydrated and active state after calcination at 700 degrees C and on the other hand the rehydrated and catalytically inactive surface (produced by contact to air) are probed. These experiments revealed the presence of significant amounts of coordinatively unsaturated sites in the form of 4-and 5-fold coordinated Al-sites on the highly dehydrated surface. In contrast to this, the rehydrated sample exhibited a severely restructured surface caused by the chemisorption of H2O which is ’constituted in a manner that was proposed in earlier models for gamma-Al2O3 surfaces. author: - first_name: L. full_name: Ahrem, L. last_name: Ahrem - first_name: G. full_name: Scholz, G. last_name: Scholz - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: B. full_name: Calvo, B. last_name: Calvo - first_name: G. full_name: Buntkowsky, G. last_name: Buntkowsky - first_name: E. full_name: Kemnitz, E. last_name: Kemnitz citation: ama: Ahrem L, Scholz G, Gutmann T, Calvo B, Buntkowsky G, Kemnitz E. Direct Observation of Coordinatively Unsaturated Sites on the Surface of a Fluoride-Doped Alumina Catalyst. Journal of Physical Chemistry C. 2017;121(22):12206–12213. doi:10.1021/acs.jpcc.7b02535 apa: Ahrem, L., Scholz, G., Gutmann, T., Calvo, B., Buntkowsky, G., & Kemnitz, E. (2017). Direct Observation of Coordinatively Unsaturated Sites on the Surface of a Fluoride-Doped Alumina Catalyst. Journal of Physical Chemistry C, 121(22), 12206–12213. https://doi.org/10.1021/acs.jpcc.7b02535 bibtex: '@article{Ahrem_Scholz_Gutmann_Calvo_Buntkowsky_Kemnitz_2017, title={Direct Observation of Coordinatively Unsaturated Sites on the Surface of a Fluoride-Doped Alumina Catalyst}, volume={121}, DOI={10.1021/acs.jpcc.7b02535}, number={22}, journal={Journal of Physical Chemistry C}, author={Ahrem, L. and Scholz, G. and Gutmann, Torsten and Calvo, B. and Buntkowsky, G. and Kemnitz, E.}, year={2017}, pages={12206–12213} }' chicago: 'Ahrem, L., G. Scholz, Torsten Gutmann, B. Calvo, G. Buntkowsky, and E. Kemnitz. “Direct Observation of Coordinatively Unsaturated Sites on the Surface of a Fluoride-Doped Alumina Catalyst.” Journal of Physical Chemistry C 121, no. 22 (2017): 12206–12213. https://doi.org/10.1021/acs.jpcc.7b02535.' ieee: 'L. Ahrem, G. Scholz, T. Gutmann, B. Calvo, G. Buntkowsky, and E. Kemnitz, “Direct Observation of Coordinatively Unsaturated Sites on the Surface of a Fluoride-Doped Alumina Catalyst,” Journal of Physical Chemistry C, vol. 121, no. 22, pp. 12206–12213, 2017, doi: 10.1021/acs.jpcc.7b02535.' mla: Ahrem, L., et al. “Direct Observation of Coordinatively Unsaturated Sites on the Surface of a Fluoride-Doped Alumina Catalyst.” Journal of Physical Chemistry C, vol. 121, no. 22, 2017, pp. 12206–12213, doi:10.1021/acs.jpcc.7b02535. short: L. Ahrem, G. Scholz, T. Gutmann, B. Calvo, G. Buntkowsky, E. Kemnitz, Journal of Physical Chemistry C 121 (2017) 12206–12213. date_created: 2026-02-07T08:56:18Z date_updated: 2026-02-17T16:19:24Z doi: 10.1021/acs.jpcc.7b02535 extern: '1' intvolume: ' 121' issue: '22' keyword: - al-27 nmr - characterization - Chemistry - cross-polarization - dynamic nuclear-polarization - eta-alumina - gamma-alumina - hydroxy fluorides - ions - Materials Science - pentacoordinated al3+ - Science & Technology - Other Topics - solid-state nmr - spectroscopic - structural insights language: - iso: eng page: 12206–12213 publication: Journal of Physical Chemistry C publication_identifier: issn: - 1932-7447 status: public title: Direct Observation of Coordinatively Unsaturated Sites on the Surface of a Fluoride-Doped Alumina Catalyst type: journal_article user_id: '100715' volume: 121 year: '2017' ... --- _id: '64065' abstract: - lang: eng text: The structure and proton tautomerism of imidazole-doped cellulose (Cell-Im), an excellent solid state proton conductor, has been studied by N-15 solid-state NMR techniques. H-1-N-15 HETCOR NMR experiments allowed us to assign the water and cellulose-OH resonances and to establish H-1-N-15 connectivities. N-15 CPMAS NMR experiments showed that imidazole is immobile and its tautomerism quenched below 263 K, whereas at higher temperatures, a broad distribution of slow and fast exchanging protons is observed, where the fraction of the latter increases with temperature. The tautomerism is found to be coupled to proton exchange with water molecules. From an analysis of the temperature-dependent fractions of both phases, a broad distribution of energies of activation of the tautomerization of Cell-Im is obtained, exhibiting a maximum at 42 kJ mol(-1) and a width of 8.2 kJ mol(-1). The tautomerization is slower than in the case of imidazole dissolved in wet organic solvents. These results indicate that imidazole is located in an aqueous fluid phase between cellulose microfibrils, where proton exchange is assisted by a fast molecular reorientation in transient hydrogen-bonded imidazole-water complexes. The implications of these findings for the mechanism of proton conductivity of Cell-Im are discussed. Finally, the potential of Dynamic Nuclear Polarization (DNP) enhanced 15N-natural abundance CP-MAS NMR of these heterocyclic systems is evaluated. author: - first_name: L. full_name: Zhao, L. last_name: Zhao - first_name: I. full_name: Smolarkiewicz, I. last_name: Smolarkiewicz - first_name: H. H. full_name: Limbach, H. H. last_name: Limbach - first_name: H. full_name: Breitzke, H. last_name: Breitzke - first_name: K. full_name: Pogorzelec-Glaser, K. last_name: Pogorzelec-Glaser - first_name: R. full_name: Pankiewicz, R. last_name: Pankiewicz - first_name: J. full_name: Tritt-Goc, J. last_name: Tritt-Goc - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: G. full_name: Buntkowsky, G. last_name: Buntkowsky citation: ama: 'Zhao L, Smolarkiewicz I, Limbach HH, et al. Imidazole-Doped Cellulose as Membrane for Fuel Cells: Structural and Dynamic Insights from Solid-State NMR. Journal of Physical Chemistry C. 2016;120(35):19574–19585. doi:10.1021/acs.jpcc.6b07049' apa: 'Zhao, L., Smolarkiewicz, I., Limbach, H. H., Breitzke, H., Pogorzelec-Glaser, K., Pankiewicz, R., Tritt-Goc, J., Gutmann, T., & Buntkowsky, G. (2016). Imidazole-Doped Cellulose as Membrane for Fuel Cells: Structural and Dynamic Insights from Solid-State NMR. Journal of Physical Chemistry C, 120(35), 19574–19585. https://doi.org/10.1021/acs.jpcc.6b07049' bibtex: '@article{Zhao_Smolarkiewicz_Limbach_Breitzke_Pogorzelec-Glaser_Pankiewicz_Tritt-Goc_Gutmann_Buntkowsky_2016, title={Imidazole-Doped Cellulose as Membrane for Fuel Cells: Structural and Dynamic Insights from Solid-State NMR}, volume={120}, DOI={10.1021/acs.jpcc.6b07049}, number={35}, journal={Journal of Physical Chemistry C}, author={Zhao, L. and Smolarkiewicz, I. and Limbach, H. H. and Breitzke, H. and Pogorzelec-Glaser, K. and Pankiewicz, R. and Tritt-Goc, J. and Gutmann, Torsten and Buntkowsky, G.}, year={2016}, pages={19574–19585} }' chicago: 'Zhao, L., I. Smolarkiewicz, H. H. Limbach, H. Breitzke, K. Pogorzelec-Glaser, R. Pankiewicz, J. Tritt-Goc, Torsten Gutmann, and G. Buntkowsky. “Imidazole-Doped Cellulose as Membrane for Fuel Cells: Structural and Dynamic Insights from Solid-State NMR.” Journal of Physical Chemistry C 120, no. 35 (2016): 19574–19585. https://doi.org/10.1021/acs.jpcc.6b07049.' ieee: 'L. Zhao et al., “Imidazole-Doped Cellulose as Membrane for Fuel Cells: Structural and Dynamic Insights from Solid-State NMR,” Journal of Physical Chemistry C, vol. 120, no. 35, pp. 19574–19585, 2016, doi: 10.1021/acs.jpcc.6b07049.' mla: 'Zhao, L., et al. “Imidazole-Doped Cellulose as Membrane for Fuel Cells: Structural and Dynamic Insights from Solid-State NMR.” Journal of Physical Chemistry C, vol. 120, no. 35, 2016, pp. 19574–19585, doi:10.1021/acs.jpcc.6b07049.' short: L. Zhao, I. Smolarkiewicz, H.H. Limbach, H. Breitzke, K. Pogorzelec-Glaser, R. Pankiewicz, J. Tritt-Goc, T. Gutmann, G. Buntkowsky, Journal of Physical Chemistry C 120 (2016) 19574–19585. date_created: 2026-02-07T16:20:10Z date_updated: 2026-02-17T16:11:56Z doi: 10.1021/acs.jpcc.6b07049 extern: '1' intvolume: ' 120' issue: '35' language: - iso: eng page: 19574–19585 publication: Journal of Physical Chemistry C publication_identifier: issn: - 1932-7447 status: public title: 'Imidazole-Doped Cellulose as Membrane for Fuel Cells: Structural and Dynamic Insights from Solid-State NMR' type: journal_article user_id: '100715' volume: 120 year: '2016' ... --- _id: '64047' abstract: - lang: eng text: A novel strategy for the immobilization of Wilkinson’s catalyst on silica nanoparticles is presented, employing pyridyl linkers as anchoring groups. The coordination binding of the catalyst to the pyridyl linker via ligand exchange of the trans-phosphine group is verified by 1 D and 2 D solid-state NMR spectroscopy. Catalytic activities are monitored by GC employing the hydrogenation of styrene as model reaction, and the leaching properties as well as the robustness of the catalyst are investigated. The resulting immobilized catalyst shows high catalytic activity, which is within a factor of three comparable to the homogeneous catalyst, and excellent stability in leaching tests. Finally, it is efficient to produce hyperpolarization in solution by employing parahydrogen-enriched hydrogen gas for hydrogenation. author: - first_name: Mohamad full_name: Srour, Mohamad last_name: Srour - first_name: Sara full_name: Hadjiali, Sara last_name: Hadjiali - first_name: Grit full_name: Sauer, Grit last_name: Sauer - first_name: Kai full_name: Brunnengräber, Kai last_name: Brunnengräber - first_name: Hergen full_name: Breitzke, Hergen last_name: Breitzke - first_name: Yeping full_name: Xu, Yeping last_name: Xu - first_name: Heiko full_name: Weidler, Heiko last_name: Weidler - first_name: Hans-Heinrich full_name: Limbach, Hans-Heinrich last_name: Limbach - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: Gerd full_name: Buntkowsky, Gerd last_name: Buntkowsky citation: ama: Srour M, Hadjiali S, Sauer G, et al. Synthesis and Solid-State NMR Characterization of a Robust, Pyridyl-Based Immobilized Wilkinson’s Type Catalyst with High Catalytic Performance. ChemCatChem. 2016;8(21):3409–3416. doi:10.1002/cctc.201600882 apa: Srour, M., Hadjiali, S., Sauer, G., Brunnengräber, K., Breitzke, H., Xu, Y., Weidler, H., Limbach, H.-H., Gutmann, T., & Buntkowsky, G. (2016). Synthesis and Solid-State NMR Characterization of a Robust, Pyridyl-Based Immobilized Wilkinson’s Type Catalyst with High Catalytic Performance. ChemCatChem, 8(21), 3409–3416. https://doi.org/10.1002/cctc.201600882 bibtex: '@article{Srour_Hadjiali_Sauer_Brunnengräber_Breitzke_Xu_Weidler_Limbach_Gutmann_Buntkowsky_2016, title={Synthesis and Solid-State NMR Characterization of a Robust, Pyridyl-Based Immobilized Wilkinson’s Type Catalyst with High Catalytic Performance}, volume={8}, DOI={10.1002/cctc.201600882}, number={21}, journal={ChemCatChem}, author={Srour, Mohamad and Hadjiali, Sara and Sauer, Grit and Brunnengräber, Kai and Breitzke, Hergen and Xu, Yeping and Weidler, Heiko and Limbach, Hans-Heinrich and Gutmann, Torsten and Buntkowsky, Gerd}, year={2016}, pages={3409–3416} }' chicago: 'Srour, Mohamad, Sara Hadjiali, Grit Sauer, Kai Brunnengräber, Hergen Breitzke, Yeping Xu, Heiko Weidler, Hans-Heinrich Limbach, Torsten Gutmann, and Gerd Buntkowsky. “Synthesis and Solid-State NMR Characterization of a Robust, Pyridyl-Based Immobilized Wilkinson’s Type Catalyst with High Catalytic Performance.” ChemCatChem 8, no. 21 (2016): 3409–3416. https://doi.org/10.1002/cctc.201600882.' ieee: 'M. Srour et al., “Synthesis and Solid-State NMR Characterization of a Robust, Pyridyl-Based Immobilized Wilkinson’s Type Catalyst with High Catalytic Performance,” ChemCatChem, vol. 8, no. 21, pp. 3409–3416, 2016, doi: 10.1002/cctc.201600882.' mla: Srour, Mohamad, et al. “Synthesis and Solid-State NMR Characterization of a Robust, Pyridyl-Based Immobilized Wilkinson’s Type Catalyst with High Catalytic Performance.” ChemCatChem, vol. 8, no. 21, 2016, pp. 3409–3416, doi:10.1002/cctc.201600882. short: M. Srour, S. Hadjiali, G. Sauer, K. Brunnengräber, H. Breitzke, Y. Xu, H. Weidler, H.-H. Limbach, T. Gutmann, G. Buntkowsky, ChemCatChem 8 (2016) 3409–3416. date_created: 2026-02-07T16:12:46Z date_updated: 2026-02-17T16:13:06Z doi: 10.1002/cctc.201600882 extern: '1' intvolume: ' 8' issue: '21' keyword: - heterogeneous catalysis - hydrogenation - immobilization - phosphane ligands - rhodium language: - iso: eng page: 3409–3416 publication: ChemCatChem status: public title: Synthesis and Solid-State NMR Characterization of a Robust, Pyridyl-Based Immobilized Wilkinson’s Type Catalyst with High Catalytic Performance type: journal_article user_id: '100715' volume: 8 year: '2016' ... --- _id: '64039' abstract: - lang: eng text: The preparation of hierarchical and sophisticated particle architectures for mimicking structural colors known from nature still remains a challenge. In this study, the preparation of novel opal and double-inverse opal films based on thermally treated metallopolymer core particles with a silica shell is described. Thermal treatment leads to the formation of magnetic nanorattle-type particles. The main challenge of artificial particles is to ensure sufficient dispersibility after several synthetic steps. Especially silica particles providing surface hydroxyl groups tend to sinter at high temperatures leading to agglomeration. We present the introduction of trimethyl ethoxy silane (TMES) as an excellent functionalization reagent as the key reaction step. The necessity and success of functionalization are investigated by transmission electron microscopy (TEM) and zeta potential measurements. Importantly, solid state NMR techniques are employed to gain deeper insights into the chemical structure of the surface-attached reagent. Finally, by this convenient functionalization the preparation of elastomeric opal films and double-inverse opal films is proven successful revealing excellent optical film properties. Moreover, magnetic properties of these novel films are investigated by using magnetic force microscopy (MFM). The herein established route is expected to pave the way for the preparation of a variety of advanced and stimuli-responsive optical materials. author: - first_name: D. full_name: Scheid, D. last_name: Scheid - first_name: D. full_name: Stock, D. last_name: Stock - first_name: T. full_name: Winter, T. last_name: Winter - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: C. full_name: Dietz, C. last_name: Dietz - first_name: M. full_name: Gallei, M. last_name: Gallei citation: ama: Scheid D, Stock D, Winter T, Gutmann T, Dietz C, Gallei M. The pivotal step of nanoparticle functionalization for the preparation of functional and magnetic hybrid opal films. Journal of Materials Chemistry C. 2016;4(11):2187–2196. doi:10.1039/c5tc04388c apa: Scheid, D., Stock, D., Winter, T., Gutmann, T., Dietz, C., & Gallei, M. (2016). The pivotal step of nanoparticle functionalization for the preparation of functional and magnetic hybrid opal films. Journal of Materials Chemistry C, 4(11), 2187–2196. https://doi.org/10.1039/c5tc04388c bibtex: '@article{Scheid_Stock_Winter_Gutmann_Dietz_Gallei_2016, title={The pivotal step of nanoparticle functionalization for the preparation of functional and magnetic hybrid opal films}, volume={4}, DOI={10.1039/c5tc04388c}, number={11}, journal={Journal of Materials Chemistry C}, author={Scheid, D. and Stock, D. and Winter, T. and Gutmann, Torsten and Dietz, C. and Gallei, M.}, year={2016}, pages={2187–2196} }' chicago: 'Scheid, D., D. Stock, T. Winter, Torsten Gutmann, C. Dietz, and M. Gallei. “The Pivotal Step of Nanoparticle Functionalization for the Preparation of Functional and Magnetic Hybrid Opal Films.” Journal of Materials Chemistry C 4, no. 11 (2016): 2187–2196. https://doi.org/10.1039/c5tc04388c.' ieee: 'D. Scheid, D. Stock, T. Winter, T. Gutmann, C. Dietz, and M. Gallei, “The pivotal step of nanoparticle functionalization for the preparation of functional and magnetic hybrid opal films,” Journal of Materials Chemistry C, vol. 4, no. 11, pp. 2187–2196, 2016, doi: 10.1039/c5tc04388c.' mla: Scheid, D., et al. “The Pivotal Step of Nanoparticle Functionalization for the Preparation of Functional and Magnetic Hybrid Opal Films.” Journal of Materials Chemistry C, vol. 4, no. 11, 2016, pp. 2187–2196, doi:10.1039/c5tc04388c. short: D. Scheid, D. Stock, T. Winter, T. Gutmann, C. Dietz, M. Gallei, Journal of Materials Chemistry C 4 (2016) 2187–2196. date_created: 2026-02-07T16:09:09Z date_updated: 2026-02-17T16:13:25Z doi: 10.1039/c5tc04388c extern: '1' intvolume: ' 4' issue: '11' keyword: - Materials Science - silica - Physics - nmr - colloidal photonic crystals - light - polymerization - solids - structural color - thermo language: - iso: eng page: 2187–2196 publication: Journal of Materials Chemistry C publication_identifier: issn: - 2050-7526 status: public title: The pivotal step of nanoparticle functionalization for the preparation of functional and magnetic hybrid opal films type: journal_article user_id: '100715' volume: 4 year: '2016' ... --- _id: '64011' abstract: - lang: eng text: Catalytically active dirhodium sheet-like coordination polymers are synthesized from their precursors via ligand exchange. The individual lamellae of the dirhodium-bdc frameworks are stacked as parallel sheets, which are randomly oriented or slightly ordered. As inorganic building blocks Rh2(TFA)4 and Rh2(OAc)4, and as organic linker benzene 1,4-dicarboxylate (bdc) are employed. The successful synthesis of the Rh2-bdc(Tf) and Rh2-bdc(Ac) catalysts is proven by ATR-IR, XPS and 13C CP MAS NMR. Residual trifluoroacetate species are investigated by quantitative 19F MAS NMR which further reflects the configuration of trifluoroacetate in the obtained Rh2-bdc(Tf), and defects in the structure. DR-UV-vis and XPS demonstrate that the oxidation state and the Rh-Rh single bond in the dirhodium node are maintained during the ligand substitution process. The stability and reusability of the catalysts are verified by TG-DTA measurements and leaching tests. The catalysts show similar catalytic efficiency as the homogeneous catalyst in the model cyclopropanation between ethyl diazoacetate (EDA) and styrene. author: - first_name: Jiquan full_name: Liu, Jiquan last_name: Liu - first_name: Claudia full_name: Fasel, Claudia last_name: Fasel - first_name: Pedro full_name: Braga-Groszewicz, Pedro last_name: Braga-Groszewicz - first_name: Niels full_name: Rothermel, Niels last_name: Rothermel - first_name: Aany Sofia full_name: Lilly Thankamony, Aany Sofia last_name: Lilly Thankamony - first_name: Grit full_name: Sauer, Grit last_name: Sauer - first_name: Yeping full_name: Xu, Yeping last_name: Xu - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: Gerd full_name: Buntkowsky, Gerd last_name: Buntkowsky citation: ama: Liu J, Fasel C, Braga-Groszewicz P, et al. Heterogeneous self-supported dirhodium(ii) catalysts with high catalytic efficiency in cyclopropanation - a structural study. Catalysis Science & Technology. 2016;6(21):7830–7840. doi:10.1039/C6CY00915H apa: Liu, J., Fasel, C., Braga-Groszewicz, P., Rothermel, N., Lilly Thankamony, A. S., Sauer, G., Xu, Y., Gutmann, T., & Buntkowsky, G. (2016). Heterogeneous self-supported dirhodium(ii) catalysts with high catalytic efficiency in cyclopropanation - a structural study. Catalysis Science & Technology, 6(21), 7830–7840. https://doi.org/10.1039/C6CY00915H bibtex: '@article{Liu_Fasel_Braga-Groszewicz_Rothermel_Lilly Thankamony_Sauer_Xu_Gutmann_Buntkowsky_2016, title={Heterogeneous self-supported dirhodium(ii) catalysts with high catalytic efficiency in cyclopropanation - a structural study}, volume={6}, DOI={10.1039/C6CY00915H}, number={21}, journal={Catalysis Science & Technology}, publisher={The Royal Society of Chemistry}, author={Liu, Jiquan and Fasel, Claudia and Braga-Groszewicz, Pedro and Rothermel, Niels and Lilly Thankamony, Aany Sofia and Sauer, Grit and Xu, Yeping and Gutmann, Torsten and Buntkowsky, Gerd}, year={2016}, pages={7830–7840} }' chicago: 'Liu, Jiquan, Claudia Fasel, Pedro Braga-Groszewicz, Niels Rothermel, Aany Sofia Lilly Thankamony, Grit Sauer, Yeping Xu, Torsten Gutmann, and Gerd Buntkowsky. “Heterogeneous Self-Supported Dirhodium(Ii) Catalysts with High Catalytic Efficiency in Cyclopropanation - a Structural Study.” Catalysis Science & Technology 6, no. 21 (2016): 7830–7840. https://doi.org/10.1039/C6CY00915H.' ieee: 'J. Liu et al., “Heterogeneous self-supported dirhodium(ii) catalysts with high catalytic efficiency in cyclopropanation - a structural study,” Catalysis Science & Technology, vol. 6, no. 21, pp. 7830–7840, 2016, doi: 10.1039/C6CY00915H.' mla: Liu, Jiquan, et al. “Heterogeneous Self-Supported Dirhodium(Ii) Catalysts with High Catalytic Efficiency in Cyclopropanation - a Structural Study.” Catalysis Science & Technology, vol. 6, no. 21, The Royal Society of Chemistry, 2016, pp. 7830–7840, doi:10.1039/C6CY00915H. short: J. Liu, C. Fasel, P. Braga-Groszewicz, N. Rothermel, A.S. Lilly Thankamony, G. Sauer, Y. Xu, T. Gutmann, G. Buntkowsky, Catalysis Science & Technology 6 (2016) 7830–7840. date_created: 2026-02-07T15:58:38Z date_updated: 2026-02-17T16:15:20Z doi: 10.1039/C6CY00915H extern: '1' intvolume: ' 6' issue: '21' language: - iso: eng page: 7830–7840 publication: Catalysis Science & Technology publication_identifier: issn: - 2044-4753 publisher: The Royal Society of Chemistry status: public title: Heterogeneous self-supported dirhodium(ii) catalysts with high catalytic efficiency in cyclopropanation - a structural study type: journal_article user_id: '100715' volume: 6 year: '2016' ... --- _id: '63939' abstract: - lang: eng text: The controlled catalytic functionalization of alkanes via the activation of C-H bonds is a significant challenge. Although C-H activation by transition metal catalysts is often suggested to operate via intermediate sigma-alkane complexes, such transient species are difficult to observe due to their instability in solution. This instability may be controlled by use of solid/gas synthetic techniques that enable the isolation of single-crystals of well-defined sigma-alkane complexes. Here we show that, using this unique platform, selective alkane C-H activation occurs, as probed by H/D exchange using D-2, and that five different isotopomers/isotopologues of the sigma-alkane complex result, as characterized by single-crystal neutron diffraction studies for three examples. Low-energy fluxional processes associated with the sigma-alkane ligand are identified using variable-temperature X-ray diffraction, solid-state NMR spectroscopy, and periodic DFT calculations. These observations connect sigma-alkane complexes with their C-H activated products, and demonstrate that alkane-ligand mobility, and selective C-H activation, are possible when these processes occur in the constrained environment of the solid-state. author: - first_name: F. M. full_name: Chadwick, F. M. last_name: Chadwick - first_name: T. full_name: Kramer, T. last_name: Kramer - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: N. H. full_name: Rees, N. H. last_name: Rees - first_name: A. L. full_name: Thompson, A. L. last_name: Thompson - first_name: A. J. full_name: Edwards, A. J. last_name: Edwards - first_name: G. full_name: Buntkowsky, G. last_name: Buntkowsky - first_name: S. A. full_name: Macgregor, S. A. last_name: Macgregor - first_name: A. S. full_name: Weller, A. S. last_name: Weller citation: ama: Chadwick FM, Kramer T, Gutmann T, et al. Selective C-H Activation at a Molecular Rhodium Sigma-Alkane Complex by Solid/Gas Single-Crystal to Single-Crystal H/D Exchange. Journal of the American Chemical Society. 2016;138(40):13369–13378. doi:10.1021/jacs.6b07968 apa: Chadwick, F. M., Kramer, T., Gutmann, T., Rees, N. H., Thompson, A. L., Edwards, A. J., Buntkowsky, G., Macgregor, S. A., & Weller, A. S. (2016). Selective C-H Activation at a Molecular Rhodium Sigma-Alkane Complex by Solid/Gas Single-Crystal to Single-Crystal H/D Exchange. Journal of the American Chemical Society, 138(40), 13369–13378. https://doi.org/10.1021/jacs.6b07968 bibtex: '@article{Chadwick_Kramer_Gutmann_Rees_Thompson_Edwards_Buntkowsky_Macgregor_Weller_2016, title={Selective C-H Activation at a Molecular Rhodium Sigma-Alkane Complex by Solid/Gas Single-Crystal to Single-Crystal H/D Exchange}, volume={138}, DOI={10.1021/jacs.6b07968}, number={40}, journal={Journal of the American Chemical Society}, author={Chadwick, F. M. and Kramer, T. and Gutmann, Torsten and Rees, N. H. and Thompson, A. L. and Edwards, A. J. and Buntkowsky, G. and Macgregor, S. A. and Weller, A. S.}, year={2016}, pages={13369–13378} }' chicago: 'Chadwick, F. M., T. Kramer, Torsten Gutmann, N. H. Rees, A. L. Thompson, A. J. Edwards, G. Buntkowsky, S. A. Macgregor, and A. S. Weller. “Selective C-H Activation at a Molecular Rhodium Sigma-Alkane Complex by Solid/Gas Single-Crystal to Single-Crystal H/D Exchange.” Journal of the American Chemical Society 138, no. 40 (2016): 13369–13378. https://doi.org/10.1021/jacs.6b07968.' ieee: 'F. M. Chadwick et al., “Selective C-H Activation at a Molecular Rhodium Sigma-Alkane Complex by Solid/Gas Single-Crystal to Single-Crystal H/D Exchange,” Journal of the American Chemical Society, vol. 138, no. 40, pp. 13369–13378, 2016, doi: 10.1021/jacs.6b07968.' mla: Chadwick, F. M., et al. “Selective C-H Activation at a Molecular Rhodium Sigma-Alkane Complex by Solid/Gas Single-Crystal to Single-Crystal H/D Exchange.” Journal of the American Chemical Society, vol. 138, no. 40, 2016, pp. 13369–13378, doi:10.1021/jacs.6b07968. short: F.M. Chadwick, T. Kramer, T. Gutmann, N.H. Rees, A.L. Thompson, A.J. Edwards, G. Buntkowsky, S.A. Macgregor, A.S. Weller, Journal of the American Chemical Society 138 (2016) 13369–13378. date_created: 2026-02-07T09:08:45Z date_updated: 2026-02-17T16:18:43Z doi: 10.1021/jacs.6b07968 extern: '1' intvolume: ' 138' issue: '40' language: - iso: eng page: 13369–13378 publication: Journal of the American Chemical Society status: public title: Selective C-H Activation at a Molecular Rhodium Sigma-Alkane Complex by Solid/Gas Single-Crystal to Single-Crystal H/D Exchange type: journal_article user_id: '100715' volume: 138 year: '2016' ... --- _id: '64060' author: - first_name: Mayke full_name: Werner, Mayke last_name: Werner - first_name: Andreas full_name: Heil, Andreas last_name: Heil - first_name: Niels full_name: Rothermel, Niels last_name: Rothermel - first_name: Hergen full_name: Breitzke, Hergen last_name: Breitzke - first_name: Pedro Braga full_name: Groszewicz, Pedro Braga last_name: Groszewicz - first_name: Aany Sofia full_name: Thankamony, Aany Sofia last_name: Thankamony - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: Gerd full_name: Buntkowsky, Gerd last_name: Buntkowsky citation: ama: Werner M, Heil A, Rothermel N, et al. Synthesis and solid state NMR characterization of novel peptide/silica hybrid materials. Solid State Nuclear Magnetic Resonance. 2015;72:73–78. doi:10.1016/j.ssnmr.2015.09.008 apa: Werner, M., Heil, A., Rothermel, N., Breitzke, H., Groszewicz, P. B., Thankamony, A. S., Gutmann, T., & Buntkowsky, G. (2015). Synthesis and solid state NMR characterization of novel peptide/silica hybrid materials. Solid State Nuclear Magnetic Resonance, 72, 73–78. https://doi.org/10.1016/j.ssnmr.2015.09.008 bibtex: '@article{Werner_Heil_Rothermel_Breitzke_Groszewicz_Thankamony_Gutmann_Buntkowsky_2015, title={Synthesis and solid state NMR characterization of novel peptide/silica hybrid materials}, volume={72}, DOI={10.1016/j.ssnmr.2015.09.008}, journal={Solid State Nuclear Magnetic Resonance}, author={Werner, Mayke and Heil, Andreas and Rothermel, Niels and Breitzke, Hergen and Groszewicz, Pedro Braga and Thankamony, Aany Sofia and Gutmann, Torsten and Buntkowsky, Gerd}, year={2015}, pages={73–78} }' chicago: 'Werner, Mayke, Andreas Heil, Niels Rothermel, Hergen Breitzke, Pedro Braga Groszewicz, Aany Sofia Thankamony, Torsten Gutmann, and Gerd Buntkowsky. “Synthesis and Solid State NMR Characterization of Novel Peptide/Silica Hybrid Materials.” Solid State Nuclear Magnetic Resonance 72 (2015): 73–78. https://doi.org/10.1016/j.ssnmr.2015.09.008.' ieee: 'M. Werner et al., “Synthesis and solid state NMR characterization of novel peptide/silica hybrid materials,” Solid State Nuclear Magnetic Resonance, vol. 72, pp. 73–78, 2015, doi: 10.1016/j.ssnmr.2015.09.008.' mla: Werner, Mayke, et al. “Synthesis and Solid State NMR Characterization of Novel Peptide/Silica Hybrid Materials.” Solid State Nuclear Magnetic Resonance, vol. 72, 2015, pp. 73–78, doi:10.1016/j.ssnmr.2015.09.008. short: M. Werner, A. Heil, N. Rothermel, H. Breitzke, P.B. Groszewicz, A.S. Thankamony, T. Gutmann, G. Buntkowsky, Solid State Nuclear Magnetic Resonance 72 (2015) 73–78. date_created: 2026-02-07T16:18:17Z date_updated: 2026-02-17T16:12:43Z doi: 10.1016/j.ssnmr.2015.09.008 extern: '1' intvolume: ' 72' language: - iso: eng page: 73–78 publication: Solid State Nuclear Magnetic Resonance status: public title: Synthesis and solid state NMR characterization of novel peptide/silica hybrid materials type: journal_article user_id: '100715' volume: 72 year: '2015' ... --- _id: '64028' author: - first_name: Tomasz full_name: Ratajczyk, Tomasz last_name: Ratajczyk - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: Piotr full_name: Bernatowicz, Piotr last_name: Bernatowicz - first_name: Gerd full_name: Buntkowsky, Gerd last_name: Buntkowsky - first_name: Jaroslaw full_name: Frydel, Jaroslaw last_name: Frydel - first_name: Bartlomiej full_name: Fedorczyk, Bartlomiej last_name: Fedorczyk citation: ama: Ratajczyk T, Gutmann T, Bernatowicz P, Buntkowsky G, Frydel J, Fedorczyk B. NMR Signal Enhancement by Effective SABRE Labeling of Oligopeptides. Chemistry A European Journal. 2015;21(36):12616–12619. doi:10.1002/chem.201501552 apa: Ratajczyk, T., Gutmann, T., Bernatowicz, P., Buntkowsky, G., Frydel, J., & Fedorczyk, B. (2015). NMR Signal Enhancement by Effective SABRE Labeling of Oligopeptides. Chemistry A European Journal, 21(36), 12616–12619. https://doi.org/10.1002/chem.201501552 bibtex: '@article{Ratajczyk_Gutmann_Bernatowicz_Buntkowsky_Frydel_Fedorczyk_2015, title={NMR Signal Enhancement by Effective SABRE Labeling of Oligopeptides}, volume={21}, DOI={10.1002/chem.201501552}, number={36}, journal={Chemistry A European Journal}, author={Ratajczyk, Tomasz and Gutmann, Torsten and Bernatowicz, Piotr and Buntkowsky, Gerd and Frydel, Jaroslaw and Fedorczyk, Bartlomiej}, year={2015}, pages={12616–12619} }' chicago: 'Ratajczyk, Tomasz, Torsten Gutmann, Piotr Bernatowicz, Gerd Buntkowsky, Jaroslaw Frydel, and Bartlomiej Fedorczyk. “NMR Signal Enhancement by Effective SABRE Labeling of Oligopeptides.” Chemistry A European Journal 21, no. 36 (2015): 12616–12619. https://doi.org/10.1002/chem.201501552.' ieee: 'T. Ratajczyk, T. Gutmann, P. Bernatowicz, G. Buntkowsky, J. Frydel, and B. Fedorczyk, “NMR Signal Enhancement by Effective SABRE Labeling of Oligopeptides,” Chemistry A European Journal, vol. 21, no. 36, pp. 12616–12619, 2015, doi: 10.1002/chem.201501552.' mla: Ratajczyk, Tomasz, et al. “NMR Signal Enhancement by Effective SABRE Labeling of Oligopeptides.” Chemistry A European Journal, vol. 21, no. 36, 2015, pp. 12616–12619, doi:10.1002/chem.201501552. short: T. Ratajczyk, T. Gutmann, P. Bernatowicz, G. Buntkowsky, J. Frydel, B. Fedorczyk, Chemistry A European Journal 21 (2015) 12616–12619. date_created: 2026-02-07T16:05:39Z date_updated: 2026-02-17T16:14:02Z doi: 10.1002/chem.201501552 extern: '1' intvolume: ' 21' issue: '36' language: - iso: eng page: 12616–12619 publication: Chemistry A European Journal status: public title: NMR Signal Enhancement by Effective SABRE Labeling of Oligopeptides type: journal_article user_id: '100715' volume: 21 year: '2015' ... --- _id: '64013' author: - first_name: Jiquan full_name: Liu, Jiquan last_name: Liu - first_name: Andreas full_name: Plog, Andreas last_name: Plog - first_name: Pedro full_name: Groszewicz, Pedro last_name: Groszewicz - first_name: Li full_name: Zhao, Li last_name: Zhao - first_name: Yeping full_name: Xu, Yeping last_name: Xu - first_name: Hergen full_name: Breitzke, Hergen last_name: Breitzke - first_name: Annegret full_name: Stark, Annegret last_name: Stark - first_name: Rudolf full_name: Hoffmann, Rudolf last_name: Hoffmann - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: Kai full_name: Zhang, Kai last_name: Zhang - first_name: Gerd full_name: Buntkowsky, Gerd last_name: Buntkowsky citation: ama: 'Liu J, Plog A, Groszewicz P, et al. Design of a Heterogeneous Catalyst Based on Cellulose Nanocrystals for Cyclopropanation: Synthesis and Solid-State NMR Characterization. Chemistry A European Journal. 2015;21(35):12414–12420. doi:10.1002/chem.201501151' apa: 'Liu, J., Plog, A., Groszewicz, P., Zhao, L., Xu, Y., Breitzke, H., Stark, A., Hoffmann, R., Gutmann, T., Zhang, K., & Buntkowsky, G. (2015). Design of a Heterogeneous Catalyst Based on Cellulose Nanocrystals for Cyclopropanation: Synthesis and Solid-State NMR Characterization. Chemistry A European Journal, 21(35), 12414–12420. https://doi.org/10.1002/chem.201501151' bibtex: '@article{Liu_Plog_Groszewicz_Zhao_Xu_Breitzke_Stark_Hoffmann_Gutmann_Zhang_et al._2015, title={Design of a Heterogeneous Catalyst Based on Cellulose Nanocrystals for Cyclopropanation: Synthesis and Solid-State NMR Characterization}, volume={21}, DOI={10.1002/chem.201501151}, number={35}, journal={Chemistry A European Journal}, author={Liu, Jiquan and Plog, Andreas and Groszewicz, Pedro and Zhao, Li and Xu, Yeping and Breitzke, Hergen and Stark, Annegret and Hoffmann, Rudolf and Gutmann, Torsten and Zhang, Kai and et al.}, year={2015}, pages={12414–12420} }' chicago: 'Liu, Jiquan, Andreas Plog, Pedro Groszewicz, Li Zhao, Yeping Xu, Hergen Breitzke, Annegret Stark, et al. “Design of a Heterogeneous Catalyst Based on Cellulose Nanocrystals for Cyclopropanation: Synthesis and Solid-State NMR Characterization.” Chemistry A European Journal 21, no. 35 (2015): 12414–12420. https://doi.org/10.1002/chem.201501151.' ieee: 'J. Liu et al., “Design of a Heterogeneous Catalyst Based on Cellulose Nanocrystals for Cyclopropanation: Synthesis and Solid-State NMR Characterization,” Chemistry A European Journal, vol. 21, no. 35, pp. 12414–12420, 2015, doi: 10.1002/chem.201501151.' mla: 'Liu, Jiquan, et al. “Design of a Heterogeneous Catalyst Based on Cellulose Nanocrystals for Cyclopropanation: Synthesis and Solid-State NMR Characterization.” Chemistry A European Journal, vol. 21, no. 35, 2015, pp. 12414–12420, doi:10.1002/chem.201501151.' short: J. Liu, A. Plog, P. Groszewicz, L. Zhao, Y. Xu, H. Breitzke, A. Stark, R. Hoffmann, T. Gutmann, K. Zhang, G. Buntkowsky, Chemistry A European Journal 21 (2015) 12414–12420. date_created: 2026-02-07T15:59:31Z date_updated: 2026-02-17T16:15:16Z doi: 10.1002/chem.201501151 extern: '1' intvolume: ' 21' issue: '35' language: - iso: eng page: 12414–12420 publication: Chemistry A European Journal status: public title: 'Design of a Heterogeneous Catalyst Based on Cellulose Nanocrystals for Cyclopropanation: Synthesis and Solid-State NMR Characterization' type: journal_article user_id: '100715' volume: 21 year: '2015' ... --- _id: '63972' author: - first_name: M. full_name: Harrach, M. last_name: Harrach - first_name: B. full_name: Drossel, B. last_name: Drossel - first_name: W. full_name: Winschel, W. last_name: Winschel - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: G. full_name: Buntkowsky, G. last_name: Buntkowsky citation: ama: Harrach M, Drossel B, Winschel W, Gutmann T, Buntkowsky G. Mixtures of Isobutyric Acid and Water Confined in Cylindrical (Silica)Nanopores Revisited - A Combined Solid-State NMR and Molecular Dynamics Simulation Study. Journal of Physical Chemistry C. 2015;119:28961–28969. apa: Harrach, M., Drossel, B., Winschel, W., Gutmann, T., & Buntkowsky, G. (2015). Mixtures of Isobutyric Acid and Water Confined in Cylindrical (Silica)Nanopores Revisited - A Combined Solid-State NMR and Molecular Dynamics Simulation Study. Journal of Physical Chemistry C, 119, 28961–28969. bibtex: '@article{Harrach_Drossel_Winschel_Gutmann_Buntkowsky_2015, title={Mixtures of Isobutyric Acid and Water Confined in Cylindrical (Silica)Nanopores Revisited - A Combined Solid-State NMR and Molecular Dynamics Simulation Study}, volume={119}, journal={Journal of Physical Chemistry C}, author={Harrach, M. and Drossel, B. and Winschel, W. and Gutmann, Torsten and Buntkowsky, G.}, year={2015}, pages={28961–28969} }' chicago: 'Harrach, M., B. Drossel, W. Winschel, Torsten Gutmann, and G. Buntkowsky. “Mixtures of Isobutyric Acid and Water Confined in Cylindrical (Silica)Nanopores Revisited - A Combined Solid-State NMR and Molecular Dynamics Simulation Study.” Journal of Physical Chemistry C 119 (2015): 28961–28969.' ieee: M. Harrach, B. Drossel, W. Winschel, T. Gutmann, and G. Buntkowsky, “Mixtures of Isobutyric Acid and Water Confined in Cylindrical (Silica)Nanopores Revisited - A Combined Solid-State NMR and Molecular Dynamics Simulation Study,” Journal of Physical Chemistry C, vol. 119, pp. 28961–28969, 2015. mla: Harrach, M., et al. “Mixtures of Isobutyric Acid and Water Confined in Cylindrical (Silica)Nanopores Revisited - A Combined Solid-State NMR and Molecular Dynamics Simulation Study.” Journal of Physical Chemistry C, vol. 119, 2015, pp. 28961–28969. short: M. Harrach, B. Drossel, W. Winschel, T. Gutmann, G. Buntkowsky, Journal of Physical Chemistry C 119 (2015) 28961–28969. date_created: 2026-02-07T15:41:18Z date_updated: 2026-02-17T16:17:27Z extern: '1' intvolume: ' 119' language: - iso: eng page: 28961–28969 publication: Journal of Physical Chemistry C publication_identifier: issn: - 1932-7447 status: public title: Mixtures of Isobutyric Acid and Water Confined in Cylindrical (Silica)Nanopores Revisited - A Combined Solid-State NMR and Molecular Dynamics Simulation Study type: journal_article user_id: '100715' volume: 119 year: '2015' ... --- _id: '63963' abstract: - lang: eng text: A novel heterogeneous dirhodium catalyst has been synthesized. This stable catalyst is constructed from dirhodium acetate dimer (Rh2(OAc)4) units, which are covalently linked to amine- and carboxyl-bifunctionalized mesoporous silica (SBA-15NH2COOH). It shows good efficiency in catalyzing the cyclopropanation reaction of styrene and ethyl diazoacetate (EDA) forming cis- and trans-1-ethoxycarbonyl-2-phenylcyclopropane. To characterize the structure of this catalyst and to confirm the successful immobilization, heteronuclear solid-state NMR experiments have been performed. The high application potential of dynamic nuclear polarization (DNP) NMR for the analysis of binding sites in this novel catalyst is demonstrated. Signal-enhanced 13C CP MAS and 15N CP MAS techniques have been employed to detect different carboxyl and amine binding sites in natural abundance on a fast time scale. The interpretation of the experimental chemical shift values for different binding sites has been corroborated by quantum chemical calculations on dirhodium model complexes. author: - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: Jiquan full_name: Liu, Jiquan last_name: Liu - first_name: Niels full_name: Rothermel, Niels last_name: Rothermel - first_name: Yeping full_name: Xu, Yeping last_name: Xu - first_name: Eva full_name: Jaumann, Eva last_name: Jaumann - first_name: Mayke full_name: Werner, Mayke last_name: Werner - first_name: Hergen full_name: Breitzke, Hergen last_name: Breitzke - first_name: Snorri T. full_name: Sigurdsson, Snorri T. last_name: Sigurdsson - first_name: Gerd full_name: Buntkowsky, Gerd last_name: Buntkowsky citation: ama: 'Gutmann T, Liu J, Rothermel N, et al. Natural Abundance 15N NMR by Dynamic Nuclear Polarization: Fast Analysis of Binding Sites of a Novel Amine-Carboxyl-Linked Immobilized Dirhodium Catalyst. Chemistry A European Journal. 2015;21(9):3798–3805. doi:10.1002/chem.201405043' apa: 'Gutmann, T., Liu, J., Rothermel, N., Xu, Y., Jaumann, E., Werner, M., Breitzke, H., Sigurdsson, S. T., & Buntkowsky, G. (2015). Natural Abundance 15N NMR by Dynamic Nuclear Polarization: Fast Analysis of Binding Sites of a Novel Amine-Carboxyl-Linked Immobilized Dirhodium Catalyst. Chemistry A European Journal, 21(9), 3798–3805. https://doi.org/10.1002/chem.201405043' bibtex: '@article{Gutmann_Liu_Rothermel_Xu_Jaumann_Werner_Breitzke_Sigurdsson_Buntkowsky_2015, title={Natural Abundance 15N NMR by Dynamic Nuclear Polarization: Fast Analysis of Binding Sites of a Novel Amine-Carboxyl-Linked Immobilized Dirhodium Catalyst}, volume={21}, DOI={10.1002/chem.201405043}, number={9}, journal={Chemistry A European Journal}, publisher={WILEY-VCH Verlag}, author={Gutmann, Torsten and Liu, Jiquan and Rothermel, Niels and Xu, Yeping and Jaumann, Eva and Werner, Mayke and Breitzke, Hergen and Sigurdsson, Snorri T. and Buntkowsky, Gerd}, year={2015}, pages={3798–3805} }' chicago: 'Gutmann, Torsten, Jiquan Liu, Niels Rothermel, Yeping Xu, Eva Jaumann, Mayke Werner, Hergen Breitzke, Snorri T. Sigurdsson, and Gerd Buntkowsky. “Natural Abundance 15N NMR by Dynamic Nuclear Polarization: Fast Analysis of Binding Sites of a Novel Amine-Carboxyl-Linked Immobilized Dirhodium Catalyst.” Chemistry A European Journal 21, no. 9 (2015): 3798–3805. https://doi.org/10.1002/chem.201405043.' ieee: 'T. Gutmann et al., “Natural Abundance 15N NMR by Dynamic Nuclear Polarization: Fast Analysis of Binding Sites of a Novel Amine-Carboxyl-Linked Immobilized Dirhodium Catalyst,” Chemistry A European Journal, vol. 21, no. 9, pp. 3798–3805, 2015, doi: 10.1002/chem.201405043.' mla: 'Gutmann, Torsten, et al. “Natural Abundance 15N NMR by Dynamic Nuclear Polarization: Fast Analysis of Binding Sites of a Novel Amine-Carboxyl-Linked Immobilized Dirhodium Catalyst.” Chemistry A European Journal, vol. 21, no. 9, WILEY-VCH Verlag, 2015, pp. 3798–3805, doi:10.1002/chem.201405043.' short: T. Gutmann, J. Liu, N. Rothermel, Y. Xu, E. Jaumann, M. Werner, H. Breitzke, S.T. Sigurdsson, G. Buntkowsky, Chemistry A European Journal 21 (2015) 3798–3805. date_created: 2026-02-07T15:38:07Z date_updated: 2026-02-17T16:17:50Z doi: 10.1002/chem.201405043 extern: '1' intvolume: ' 21' issue: '9' keyword: - heterogeneous catalysis - immobilized catalyst - dynamic nuclear polarization - hyperpolarization - NMR spectroscopy language: - iso: eng page: 3798–3805 publication: Chemistry A European Journal publisher: WILEY-VCH Verlag status: public title: 'Natural Abundance 15N NMR by Dynamic Nuclear Polarization: Fast Analysis of Binding Sites of a Novel Amine-Carboxyl-Linked Immobilized Dirhodium Catalyst' type: journal_article user_id: '100715' volume: 21 year: '2015' ... --- _id: '63937' author: - first_name: Israel full_name: Cano, Israel last_name: Cano - first_name: Miguel A. full_name: Huertos, Miguel A. last_name: Huertos - first_name: Andrew M. full_name: Chapman, Andrew M. last_name: Chapman - first_name: Gerd full_name: Buntkowsky, Gerd last_name: Buntkowsky - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: Pedro B. full_name: Groszewicz, Pedro B. last_name: Groszewicz - first_name: Piet W. N. M. full_name: van Leeuwen, Piet W. N. M. last_name: van Leeuwen citation: ama: 'Cano I, Huertos MA, Chapman AM, et al. Air-Stable Gold Nanoparticles Ligated by Secondary Phosphine Oxides as Catalyst for the Chemoselective Hydrogenation of Substituted Aldehydes: a Remarkable Ligand Effect. Journal of the American Chemical Society. 2015;137(24):7718–7727. doi:10.1021/jacs.5b02802' apa: 'Cano, I., Huertos, M. A., Chapman, A. M., Buntkowsky, G., Gutmann, T., Groszewicz, P. B., & van Leeuwen, P. W. N. M. (2015). Air-Stable Gold Nanoparticles Ligated by Secondary Phosphine Oxides as Catalyst for the Chemoselective Hydrogenation of Substituted Aldehydes: a Remarkable Ligand Effect. Journal of the American Chemical Society, 137(24), 7718–7727. https://doi.org/10.1021/jacs.5b02802' bibtex: '@article{Cano_Huertos_Chapman_Buntkowsky_Gutmann_Groszewicz_van Leeuwen_2015, title={Air-Stable Gold Nanoparticles Ligated by Secondary Phosphine Oxides as Catalyst for the Chemoselective Hydrogenation of Substituted Aldehydes: a Remarkable Ligand Effect}, volume={137}, DOI={10.1021/jacs.5b02802}, number={24}, journal={Journal of the American Chemical Society}, author={Cano, Israel and Huertos, Miguel A. and Chapman, Andrew M. and Buntkowsky, Gerd and Gutmann, Torsten and Groszewicz, Pedro B. and van Leeuwen, Piet W. N. M.}, year={2015}, pages={7718–7727} }' chicago: 'Cano, Israel, Miguel A. Huertos, Andrew M. Chapman, Gerd Buntkowsky, Torsten Gutmann, Pedro B. Groszewicz, and Piet W. N. M. van Leeuwen. “Air-Stable Gold Nanoparticles Ligated by Secondary Phosphine Oxides as Catalyst for the Chemoselective Hydrogenation of Substituted Aldehydes: A Remarkable Ligand Effect.” Journal of the American Chemical Society 137, no. 24 (2015): 7718–7727. https://doi.org/10.1021/jacs.5b02802.' ieee: 'I. Cano et al., “Air-Stable Gold Nanoparticles Ligated by Secondary Phosphine Oxides as Catalyst for the Chemoselective Hydrogenation of Substituted Aldehydes: a Remarkable Ligand Effect,” Journal of the American Chemical Society, vol. 137, no. 24, pp. 7718–7727, 2015, doi: 10.1021/jacs.5b02802.' mla: 'Cano, Israel, et al. “Air-Stable Gold Nanoparticles Ligated by Secondary Phosphine Oxides as Catalyst for the Chemoselective Hydrogenation of Substituted Aldehydes: A Remarkable Ligand Effect.” Journal of the American Chemical Society, vol. 137, no. 24, 2015, pp. 7718–7727, doi:10.1021/jacs.5b02802.' short: I. Cano, M.A. Huertos, A.M. Chapman, G. Buntkowsky, T. Gutmann, P.B. Groszewicz, P.W.N.M. van Leeuwen, Journal of the American Chemical Society 137 (2015) 7718–7727. date_created: 2026-02-07T09:08:00Z date_updated: 2026-02-17T16:18:47Z doi: 10.1021/jacs.5b02802 extern: '1' intvolume: ' 137' issue: '24' language: - iso: eng page: 7718–7727 publication: Journal of the American Chemical Society status: public title: 'Air-Stable Gold Nanoparticles Ligated by Secondary Phosphine Oxides as Catalyst for the Chemoselective Hydrogenation of Substituted Aldehydes: a Remarkable Ligand Effect' type: journal_article user_id: '100715' volume: 137 year: '2015' ... --- _id: '63935' author: - first_name: Gerd full_name: Buntkowsky, Gerd last_name: Buntkowsky - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann citation: ama: 'Buntkowsky G, Gutmann T. A Mousetrap for Carbenium Ions: NMR Detectives at Work. Angewandte Chemie International Edition. 2015;54(33):9450–9451. doi:10.1002/anie.201504899' apa: 'Buntkowsky, G., & Gutmann, T. (2015). A Mousetrap for Carbenium Ions: NMR Detectives at Work. Angewandte Chemie International Edition, 54(33), 9450–9451. https://doi.org/10.1002/anie.201504899' bibtex: '@article{Buntkowsky_Gutmann_2015, title={A Mousetrap for Carbenium Ions: NMR Detectives at Work}, volume={54}, DOI={10.1002/anie.201504899}, number={33}, journal={Angewandte Chemie International Edition}, author={Buntkowsky, Gerd and Gutmann, Torsten}, year={2015}, pages={9450–9451} }' chicago: 'Buntkowsky, Gerd, and Torsten Gutmann. “A Mousetrap for Carbenium Ions: NMR Detectives at Work.” Angewandte Chemie International Edition 54, no. 33 (2015): 9450–9451. https://doi.org/10.1002/anie.201504899.' ieee: 'G. Buntkowsky and T. Gutmann, “A Mousetrap for Carbenium Ions: NMR Detectives at Work,” Angewandte Chemie International Edition, vol. 54, no. 33, pp. 9450–9451, 2015, doi: 10.1002/anie.201504899.' mla: 'Buntkowsky, Gerd, and Torsten Gutmann. “A Mousetrap for Carbenium Ions: NMR Detectives at Work.” Angewandte Chemie International Edition, vol. 54, no. 33, 2015, pp. 9450–9451, doi:10.1002/anie.201504899.' short: G. Buntkowsky, T. Gutmann, Angewandte Chemie International Edition 54 (2015) 9450–9451. date_created: 2026-02-07T09:06:46Z date_updated: 2026-02-17T16:18:53Z doi: 10.1002/anie.201504899 extern: '1' intvolume: ' 54' issue: '33' language: - iso: eng page: 9450–9451 publication: Angewandte Chemie International Edition status: public title: 'A Mousetrap for Carbenium Ions: NMR Detectives at Work' type: journal_article user_id: '100715' volume: 54 year: '2015' ... --- _id: '64066' abstract: - lang: eng text: Multi-stimuli responsive materials based on cellulose nanocrystals (CNCs), especially using non-conventional stimuli including light, still need more explorations, to fulfill the requirements of complicated application environments. The structure determination of functional groups on the CNC surface constitutes a significant challenge, partially due to their low amounts. In this study, rhodamine spiroamide groups are immobilized onto the surface of CNCs leading to a hybrid compound being responsive to pH-values, heat and UV light. After the treatment with external stimuli, the fluorescent and correlated optical color change can be induced, which refers to a ring opening and closing process. Amine and amide groups in rhodamine spiroamide play the critical role in this switching process. Solid-state NMR spectroscopy coupled with sensitivity-enhanced dynamic nuclear polarization (DNP) was used to measure 13C and 15N in natural abundance, allowing the determination of structural changes during the switching process. It is shown that a temporary bond through an electrostatic interaction could be formed within the confined environment on the CNC surface during the heat treatment. The carboxyl groups on the CNC surface play a pivotal role in stabilizing the open status of rhodamine spiroamide groups. author: - first_name: Li full_name: Zhao, Li last_name: Zhao - first_name: Wei full_name: Li, Wei last_name: Li - first_name: Andreas full_name: Plog, Andreas last_name: Plog - first_name: Yeping full_name: Xu, Yeping last_name: Xu - first_name: Gerd full_name: Buntkowsky, Gerd last_name: Buntkowsky - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: Kai full_name: Zhang, Kai last_name: Zhang citation: ama: 'Zhao L, Li W, Plog A, et al. Multi-responsive cellulose nanocrystal-rhodamine conjugates: an advanced structure study by solid-state dynamic nuclear polarization (DNP) NMR. Physical Chemistry Chemical Physics. 2014;16(47):26322–26329. doi:10.1039/C4CP04096A' apa: 'Zhao, L., Li, W., Plog, A., Xu, Y., Buntkowsky, G., Gutmann, T., & Zhang, K. (2014). Multi-responsive cellulose nanocrystal-rhodamine conjugates: an advanced structure study by solid-state dynamic nuclear polarization (DNP) NMR. Physical Chemistry Chemical Physics, 16(47), 26322–26329. https://doi.org/10.1039/C4CP04096A' bibtex: '@article{Zhao_Li_Plog_Xu_Buntkowsky_Gutmann_Zhang_2014, title={Multi-responsive cellulose nanocrystal-rhodamine conjugates: an advanced structure study by solid-state dynamic nuclear polarization (DNP) NMR}, volume={16}, DOI={10.1039/C4CP04096A}, number={47}, journal={Physical Chemistry Chemical Physics}, publisher={The Royal Society of Chemistry}, author={Zhao, Li and Li, Wei and Plog, Andreas and Xu, Yeping and Buntkowsky, Gerd and Gutmann, Torsten and Zhang, Kai}, year={2014}, pages={26322–26329} }' chicago: 'Zhao, Li, Wei Li, Andreas Plog, Yeping Xu, Gerd Buntkowsky, Torsten Gutmann, and Kai Zhang. “Multi-Responsive Cellulose Nanocrystal-Rhodamine Conjugates: An Advanced Structure Study by Solid-State Dynamic Nuclear Polarization (DNP) NMR.” Physical Chemistry Chemical Physics 16, no. 47 (2014): 26322–26329. https://doi.org/10.1039/C4CP04096A.' ieee: 'L. Zhao et al., “Multi-responsive cellulose nanocrystal-rhodamine conjugates: an advanced structure study by solid-state dynamic nuclear polarization (DNP) NMR,” Physical Chemistry Chemical Physics, vol. 16, no. 47, pp. 26322–26329, 2014, doi: 10.1039/C4CP04096A.' mla: 'Zhao, Li, et al. “Multi-Responsive Cellulose Nanocrystal-Rhodamine Conjugates: An Advanced Structure Study by Solid-State Dynamic Nuclear Polarization (DNP) NMR.” Physical Chemistry Chemical Physics, vol. 16, no. 47, The Royal Society of Chemistry, 2014, pp. 26322–26329, doi:10.1039/C4CP04096A.' short: L. Zhao, W. Li, A. Plog, Y. Xu, G. Buntkowsky, T. Gutmann, K. Zhang, Physical Chemistry Chemical Physics 16 (2014) 26322–26329. date_created: 2026-02-07T16:20:24Z date_updated: 2026-02-17T16:11:46Z doi: 10.1039/C4CP04096A extern: '1' intvolume: ' 16' issue: '47' language: - iso: eng page: 26322–26329 publication: Physical Chemistry Chemical Physics publisher: The Royal Society of Chemistry status: public title: 'Multi-responsive cellulose nanocrystal-rhodamine conjugates: an advanced structure study by solid-state dynamic nuclear polarization (DNP) NMR' type: journal_article user_id: '100715' volume: 16 year: '2014' ... --- _id: '64064' author: - first_name: Yeping full_name: Xu, Yeping last_name: Xu - first_name: Tobias full_name: Watermann, Tobias last_name: Watermann - first_name: Hans-Heinrich full_name: Limbach, Hans-Heinrich last_name: Limbach - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: Daniel full_name: Sebastiani, Daniel last_name: Sebastiani - first_name: Gerd full_name: Buntkowsky, Gerd last_name: Buntkowsky citation: ama: Xu Y, Watermann T, Limbach H-H, Gutmann T, Sebastiani D, Buntkowsky G. Water and small organic molecules as probes for geometric confinement in well-ordered mesoporous carbon materials. Physical Chemistry Chemical Physics. 2014;16(20):9327–9336. doi:10.1039/c4cp00808a apa: Xu, Y., Watermann, T., Limbach, H.-H., Gutmann, T., Sebastiani, D., & Buntkowsky, G. (2014). Water and small organic molecules as probes for geometric confinement in well-ordered mesoporous carbon materials. Physical Chemistry Chemical Physics, 16(20), 9327–9336. https://doi.org/10.1039/c4cp00808a bibtex: '@article{Xu_Watermann_Limbach_Gutmann_Sebastiani_Buntkowsky_2014, title={Water and small organic molecules as probes for geometric confinement in well-ordered mesoporous carbon materials}, volume={16}, DOI={10.1039/c4cp00808a}, number={20}, journal={Physical Chemistry Chemical Physics}, author={Xu, Yeping and Watermann, Tobias and Limbach, Hans-Heinrich and Gutmann, Torsten and Sebastiani, Daniel and Buntkowsky, Gerd}, year={2014}, pages={9327–9336} }' chicago: 'Xu, Yeping, Tobias Watermann, Hans-Heinrich Limbach, Torsten Gutmann, Daniel Sebastiani, and Gerd Buntkowsky. “Water and Small Organic Molecules as Probes for Geometric Confinement in Well-Ordered Mesoporous Carbon Materials.” Physical Chemistry Chemical Physics 16, no. 20 (2014): 9327–9336. https://doi.org/10.1039/c4cp00808a.' ieee: 'Y. Xu, T. Watermann, H.-H. Limbach, T. Gutmann, D. Sebastiani, and G. Buntkowsky, “Water and small organic molecules as probes for geometric confinement in well-ordered mesoporous carbon materials,” Physical Chemistry Chemical Physics, vol. 16, no. 20, pp. 9327–9336, 2014, doi: 10.1039/c4cp00808a.' mla: Xu, Yeping, et al. “Water and Small Organic Molecules as Probes for Geometric Confinement in Well-Ordered Mesoporous Carbon Materials.” Physical Chemistry Chemical Physics, vol. 16, no. 20, 2014, pp. 9327–9336, doi:10.1039/c4cp00808a. short: Y. Xu, T. Watermann, H.-H. Limbach, T. Gutmann, D. Sebastiani, G. Buntkowsky, Physical Chemistry Chemical Physics 16 (2014) 9327–9336. date_created: 2026-02-07T16:19:56Z date_updated: 2026-02-17T16:12:31Z doi: 10.1039/c4cp00808a extern: '1' intvolume: ' 16' issue: '20' language: - iso: eng page: 9327–9336 publication: Physical Chemistry Chemical Physics status: public title: Water and small organic molecules as probes for geometric confinement in well-ordered mesoporous carbon materials type: journal_article user_id: '100715' volume: 16 year: '2014' ...