--- _id: '63991' abstract: - lang: eng text: A series of 1 and 2 nm sized platinum nanoparticles (Pt-NPs) deposited on different support materials, namely, gamma-alumina (gamma-Al2O3), titanium dioxide (TiO2), silicon dioxide (SiO2) and fumed silica are investigated by solid-state NMR and dynamic nuclear polarization enhanced NMR spectroscopy (DNP). DNP signal enhancement factors up to 170 enable gaining deeper insight into the surface chemistry of Pt-NPs. Carbon monoxide is used as a probe molecule to analyze the adsorption process and the surface chemistry on the supported Pt-NPs. The studied systems show significant catalytic activity in carbon monoxide oxidation on their surface at room temperature. The underlying catalytic mechanism is the water-gas shift reaction. In the case of alumina as the support the produced CO2 reacts with the surface to form carbonate, which is revealed by solid-state NMR. A similar carbonate formation is also observed when physical mixtures of neat alumina with silica, fumed silica and titania supported Pt-NPs are studied. author: - first_name: V. full_name: Klimavicius, V. last_name: Klimavicius - first_name: S. full_name: Neumann, S. last_name: Neumann - first_name: S. full_name: Kunz, S. last_name: Kunz - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: G. full_name: Buntkowsky, G. last_name: Buntkowsky citation: ama: Klimavicius V, Neumann S, Kunz S, Gutmann T, Buntkowsky G. Room temperature CO oxidation catalysed by supported Pt nanoparticles revealed by solid-state NMR and DNP spectroscopy. Catalysis Science & Technology. 2019;9(14):3743–3752. doi:10.1039/c9cy00684b apa: Klimavicius, V., Neumann, S., Kunz, S., Gutmann, T., & Buntkowsky, G. (2019). Room temperature CO oxidation catalysed by supported Pt nanoparticles revealed by solid-state NMR and DNP spectroscopy. Catalysis Science & Technology, 9(14), 3743–3752. https://doi.org/10.1039/c9cy00684b bibtex: '@article{Klimavicius_Neumann_Kunz_Gutmann_Buntkowsky_2019, title={Room temperature CO oxidation catalysed by supported Pt nanoparticles revealed by solid-state NMR and DNP spectroscopy}, volume={9}, DOI={10.1039/c9cy00684b}, number={14}, journal={Catalysis Science & Technology}, author={Klimavicius, V. and Neumann, S. and Kunz, S. and Gutmann, Torsten and Buntkowsky, G.}, year={2019}, pages={3743–3752} }' chicago: 'Klimavicius, V., S. Neumann, S. Kunz, Torsten Gutmann, and G. Buntkowsky. “Room Temperature CO Oxidation Catalysed by Supported Pt Nanoparticles Revealed by Solid-State NMR and DNP Spectroscopy.” Catalysis Science & Technology 9, no. 14 (2019): 3743–3752. https://doi.org/10.1039/c9cy00684b.' ieee: 'V. Klimavicius, S. Neumann, S. Kunz, T. Gutmann, and G. Buntkowsky, “Room temperature CO oxidation catalysed by supported Pt nanoparticles revealed by solid-state NMR and DNP spectroscopy,” Catalysis Science & Technology, vol. 9, no. 14, pp. 3743–3752, 2019, doi: 10.1039/c9cy00684b.' mla: Klimavicius, V., et al. “Room Temperature CO Oxidation Catalysed by Supported Pt Nanoparticles Revealed by Solid-State NMR and DNP Spectroscopy.” Catalysis Science & Technology, vol. 9, no. 14, 2019, pp. 3743–3752, doi:10.1039/c9cy00684b. short: V. Klimavicius, S. Neumann, S. Kunz, T. Gutmann, G. Buntkowsky, Catalysis Science & Technology 9 (2019) 3743–3752. date_created: 2026-02-07T15:47:21Z date_updated: 2026-02-17T16:16:33Z doi: 10.1039/c9cy00684b extern: '1' intvolume: ' 9' issue: '14' keyword: - Chemistry - gamma-alumina - hydrogenation - silica - c-13 - interactions - metal-catalysts - particle-size - platinum nanoparticles - sites - surface - water-gas shift language: - iso: eng page: 3743–3752 publication: Catalysis Science & Technology publication_identifier: issn: - 2044-4753 status: public title: Room temperature CO oxidation catalysed by supported Pt nanoparticles revealed by solid-state NMR and DNP spectroscopy type: journal_article user_id: '100715' volume: 9 year: '2019' ... --- _id: '63969' abstract: - lang: eng text: A number of Ir-N-heterocyclic carbene (Ir-NHC) complexes with asymmetric N-heterocyclic carbene (NHC) ligands have been prepared and examined for signal amplification by reversible exchange (SABRE). Pyridine was chosen as model compound for hyperpolarization experiments. This substrate was examined in a solvent mixture using several Ir-NHC complexes, which differ in their NHC ligands. The SABRE polarization was created at 6mT and the H-1 nuclear magnetic resonancesignals were detected at 7T. We show that asymmetric NHC ligands, because of their favorable chemistry, can adapt the SABREactive complexes to different chemical scenarios. author: - first_name: S. full_name: Hadjiali, S. last_name: Hadjiali - first_name: R. full_name: Savka, R. last_name: Savka - first_name: M. full_name: Plaumann, M. last_name: Plaumann - first_name: U. full_name: Bommerich, U. last_name: Bommerich - first_name: S. full_name: Bothe, S. last_name: Bothe - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: T. full_name: Ratajczyk, T. last_name: Ratajczyk - first_name: J. full_name: Bernarding, J. last_name: Bernarding - first_name: H. H. full_name: Limbach, H. H. last_name: Limbach - first_name: H. full_name: Plenio, H. last_name: Plenio - first_name: G. full_name: Buntkowsky, G. last_name: Buntkowsky citation: ama: Hadjiali S, Savka R, Plaumann M, et al. Substituent Influences on the NMR Signal Amplification of Ir Complexes with Heterocyclic Carbene Ligands. Applied Magnetic Resonance. 2019;50(7):895–902. doi:10.1007/s00723-019-01115-x apa: Hadjiali, S., Savka, R., Plaumann, M., Bommerich, U., Bothe, S., Gutmann, T., Ratajczyk, T., Bernarding, J., Limbach, H. H., Plenio, H., & Buntkowsky, G. (2019). Substituent Influences on the NMR Signal Amplification of Ir Complexes with Heterocyclic Carbene Ligands. Applied Magnetic Resonance, 50(7), 895–902. https://doi.org/10.1007/s00723-019-01115-x bibtex: '@article{Hadjiali_Savka_Plaumann_Bommerich_Bothe_Gutmann_Ratajczyk_Bernarding_Limbach_Plenio_et al._2019, title={Substituent Influences on the NMR Signal Amplification of Ir Complexes with Heterocyclic Carbene Ligands}, volume={50}, DOI={10.1007/s00723-019-01115-x}, number={7}, journal={Applied Magnetic Resonance}, author={Hadjiali, S. and Savka, R. and Plaumann, M. and Bommerich, U. and Bothe, S. and Gutmann, Torsten and Ratajczyk, T. and Bernarding, J. and Limbach, H. H. and Plenio, H. and et al.}, year={2019}, pages={895–902} }' chicago: 'Hadjiali, S., R. Savka, M. Plaumann, U. Bommerich, S. Bothe, Torsten Gutmann, T. Ratajczyk, et al. “Substituent Influences on the NMR Signal Amplification of Ir Complexes with Heterocyclic Carbene Ligands.” Applied Magnetic Resonance 50, no. 7 (2019): 895–902. https://doi.org/10.1007/s00723-019-01115-x.' ieee: 'S. Hadjiali et al., “Substituent Influences on the NMR Signal Amplification of Ir Complexes with Heterocyclic Carbene Ligands,” Applied Magnetic Resonance, vol. 50, no. 7, pp. 895–902, 2019, doi: 10.1007/s00723-019-01115-x.' mla: Hadjiali, S., et al. “Substituent Influences on the NMR Signal Amplification of Ir Complexes with Heterocyclic Carbene Ligands.” Applied Magnetic Resonance, vol. 50, no. 7, 2019, pp. 895–902, doi:10.1007/s00723-019-01115-x. short: S. Hadjiali, R. Savka, M. Plaumann, U. Bommerich, S. Bothe, T. Gutmann, T. Ratajczyk, J. Bernarding, H.H. Limbach, H. Plenio, G. Buntkowsky, Applied Magnetic Resonance 50 (2019) 895–902. date_created: 2026-02-07T15:40:18Z date_updated: 2026-02-17T16:17:34Z doi: 10.1007/s00723-019-01115-x extern: '1' intvolume: ' 50' issue: '7' keyword: - dynamic nuclear-polarization - hyperpolarization - enhancement - hydrogen induced polarization - olefin-metathesis catalysts - parahydrogen-induced polarization - peptides - Physics - sabre - spectroscopy language: - iso: eng page: 895–902 publication: Applied Magnetic Resonance publication_identifier: issn: - 1613-7507 status: public title: Substituent Influences on the NMR Signal Amplification of Ir Complexes with Heterocyclic Carbene Ligands type: journal_article user_id: '100715' volume: 50 year: '2019' ... --- _id: '64010' abstract: - lang: eng text: Seven novel dirhodium coordination polymers (Rh-2-Ln) (n = 1-7) are prepared by employing bitopic ligands to connect dirhodium nodes. The formation of the framework is confirmed by attenuated total reflectance Fourier transform infrared (ATR-FTIR) and H-1 C-13 cross polarization magic angle spinning nuclear magnetic resonance (CP MAS NMR) spectroscopy. Defect sites resulting from incomplete ligand substitution are revealed by F-19 MAS NMR. The random stacking behavior of the frameworks in the obtained solid is analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The Rh-2/O interaction in neighboring layers is investigated by diffuse reflectance ultra-violet visible light (DR-UV-vis) spectroscopy and X-ray photoelectron spectroscopy (XPS). This interaction is relevant to understand the catalytic behavior of various Rh-2-Ln catalysts in the cyclopropanation of styrene with ethyl diazoacetate (EDA). In this context, the structure-reactivity relationship is discussed by taking into consideration both interlayer Rh-2/O interactions and steric effects of side chains. author: - first_name: J. Q. full_name: Liu, J. Q. last_name: Liu - first_name: Y. P. full_name: Xu, Y. P. last_name: Xu - first_name: P. B. full_name: Groszewicz, P. B. last_name: Groszewicz - first_name: M. full_name: Brodrecht, M. last_name: Brodrecht - first_name: C. full_name: Fasel, C. last_name: Fasel - first_name: K. full_name: Hofmann, K. last_name: Hofmann - first_name: X. J. full_name: Tan, X. J. last_name: Tan - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: G. full_name: Buntkowsky, G. last_name: Buntkowsky citation: ama: 'Liu JQ, Xu YP, Groszewicz PB, et al. Novel dirhodium coordination polymers: the impact of side chains on cyclopropanation. Catalysis Science & Technology. 2018;8(20):5190–5200. doi:10.1039/c8cy01493k' apa: 'Liu, J. Q., Xu, Y. P., Groszewicz, P. B., Brodrecht, M., Fasel, C., Hofmann, K., Tan, X. J., Gutmann, T., & Buntkowsky, G. (2018). Novel dirhodium coordination polymers: the impact of side chains on cyclopropanation. Catalysis Science & Technology, 8(20), 5190–5200. https://doi.org/10.1039/c8cy01493k' bibtex: '@article{Liu_Xu_Groszewicz_Brodrecht_Fasel_Hofmann_Tan_Gutmann_Buntkowsky_2018, title={Novel dirhodium coordination polymers: the impact of side chains on cyclopropanation}, volume={8}, DOI={10.1039/c8cy01493k}, number={20}, journal={Catalysis Science & Technology}, author={Liu, J. Q. and Xu, Y. P. and Groszewicz, P. B. and Brodrecht, M. and Fasel, C. and Hofmann, K. and Tan, X. J. and Gutmann, Torsten and Buntkowsky, G.}, year={2018}, pages={5190–5200} }' chicago: 'Liu, J. Q., Y. P. Xu, P. B. Groszewicz, M. Brodrecht, C. Fasel, K. Hofmann, X. J. Tan, Torsten Gutmann, and G. Buntkowsky. “Novel Dirhodium Coordination Polymers: The Impact of Side Chains on Cyclopropanation.” Catalysis Science & Technology 8, no. 20 (2018): 5190–5200. https://doi.org/10.1039/c8cy01493k.' ieee: 'J. Q. Liu et al., “Novel dirhodium coordination polymers: the impact of side chains on cyclopropanation,” Catalysis Science & Technology, vol. 8, no. 20, pp. 5190–5200, 2018, doi: 10.1039/c8cy01493k.' mla: 'Liu, J. Q., et al. “Novel Dirhodium Coordination Polymers: The Impact of Side Chains on Cyclopropanation.” Catalysis Science & Technology, vol. 8, no. 20, 2018, pp. 5190–5200, doi:10.1039/c8cy01493k.' short: J.Q. Liu, Y.P. Xu, P.B. Groszewicz, M. Brodrecht, C. Fasel, K. Hofmann, X.J. Tan, T. Gutmann, G. Buntkowsky, Catalysis Science & Technology 8 (2018) 5190–5200. date_created: 2026-02-07T15:57:34Z date_updated: 2026-02-17T16:15:22Z doi: 10.1039/c8cy01493k extern: '1' intvolume: ' 8' issue: '20' keyword: - Chemistry - asymmetric cyclopropanation - c-h insertion - carbene transformations - carboxylates - catalysts - functionalization - immobilization - metal-organic frameworks - nmr - solid support language: - iso: eng page: 5190–5200 publication: Catalysis Science & Technology publication_identifier: issn: - 2044-4753 status: public title: 'Novel dirhodium coordination polymers: the impact of side chains on cyclopropanation' type: journal_article user_id: '100715' volume: 8 year: '2018' ... --- _id: '64053' abstract: - lang: eng text: The utilization and preparation of functional hybrid films for optical sensing applications and membranes is of utmost importance. In this work, we report the convenient and scalable preparation of self-crosslinking particle-based films derived by directed self-assembly of alkoxysilane-based cross-linkers as part of a core-shell particle architecture. The synthesis of well-designed monodisperse core-shell particles by emulsion polymerization is the basic prerequisite for subsequent particle processing via the melt-shear organization technique. In more detail, the core particles consist of polystyrene (PS) or poly(methyl methacrylate) (PMMA), while the comparably soft particle shell consists of poly(ethyl acrylate) (PEA) and different alkoxysilane-based poly(methacrylate)s. For hybrid film formation and convenient self-cross-linking, different alkyl groups at the siloxane moieties were investigated in detail by solid-state Magic-Angle Spinning Nuclear Magnetic Resonance (MAS, NMR) spectroscopy revealing different crosslinking capabilities, which strongly influence the properties of the core or shell particle films with respect to transparency and iridescent reflection colors. Furthermore, solid-state NMR spectroscopy and investigation of the thermal properties by differential scanning calorimetry (DSC) measurements allow for insights into the cross-linking capabilities prior to and after synthesis, as well as after the thermally and pressure-induced processing steps. Subsequently, free-standing and self-crosslinked particle-based films featuring excellent particle order are obtained by application of the melt-shear organization technique, as shown by microscopy (TEM, SEM). author: - first_name: S. full_name: Vowinkel, S. last_name: Vowinkel - first_name: S. full_name: Paul, S. last_name: Paul - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: M. full_name: Gallei, M. last_name: Gallei citation: ama: Vowinkel S, Paul S, Gutmann T, Gallei M. Free-Standing and Self-Crosslinkable Hybrid Films by Core-Shell Particle Design and Processing. Nanomaterials. 2017;7(11):390. doi:10.3390/nano7110390 apa: Vowinkel, S., Paul, S., Gutmann, T., & Gallei, M. (2017). Free-Standing and Self-Crosslinkable Hybrid Films by Core-Shell Particle Design and Processing. Nanomaterials, 7(11), 390. https://doi.org/10.3390/nano7110390 bibtex: '@article{Vowinkel_Paul_Gutmann_Gallei_2017, title={Free-Standing and Self-Crosslinkable Hybrid Films by Core-Shell Particle Design and Processing}, volume={7}, DOI={10.3390/nano7110390}, number={11}, journal={Nanomaterials}, author={Vowinkel, S. and Paul, S. and Gutmann, Torsten and Gallei, M.}, year={2017}, pages={390} }' chicago: 'Vowinkel, S., S. Paul, Torsten Gutmann, and M. Gallei. “Free-Standing and Self-Crosslinkable Hybrid Films by Core-Shell Particle Design and Processing.” Nanomaterials 7, no. 11 (2017): 390. https://doi.org/10.3390/nano7110390.' ieee: 'S. Vowinkel, S. Paul, T. Gutmann, and M. Gallei, “Free-Standing and Self-Crosslinkable Hybrid Films by Core-Shell Particle Design and Processing,” Nanomaterials, vol. 7, no. 11, p. 390, 2017, doi: 10.3390/nano7110390.' mla: Vowinkel, S., et al. “Free-Standing and Self-Crosslinkable Hybrid Films by Core-Shell Particle Design and Processing.” Nanomaterials, vol. 7, no. 11, 2017, p. 390, doi:10.3390/nano7110390. short: S. Vowinkel, S. Paul, T. Gutmann, M. Gallei, Nanomaterials 7 (2017) 390. date_created: 2026-02-07T16:15:23Z date_updated: 2026-02-17T16:12:54Z doi: 10.3390/nano7110390 extern: '1' intvolume: ' 7' issue: '11' keyword: - Materials Science - Science & Technology - Other Topics - solid-state nmr - spectroscopy - catalysts - colloidal crystals - colloids - cross-linking - elastomeric opal films - emulsion polymerization - gamma-methacryloxypropyltrimethoxysilane - hybrid films - melt-shear organization - nanoparticles - particle - photons - polymers - processing - self-assembly - transition language: - iso: eng page: '390' publication: Nanomaterials publication_identifier: issn: - 2079-4991 status: public title: Free-Standing and Self-Crosslinkable Hybrid Films by Core-Shell Particle Design and Processing type: journal_article user_id: '100715' volume: 7 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' ...