Synthesis and DNP enhanced Solid-State-NMR Characterization of immobilized enantioselective Catalysts.
Final Report Abstract
The main results of this project can be summarized as follows: (1) A novel synthetic route to obtain benzophenone functionalized cellulose has been proposed that can be further used to prepare self-standing polymer films. The success of the functionalization was monitored by 1D and 2D solid state NMR techniques including the use of natural abundance DNP enhanced 15N solid-state NMR that proves the coupling of benzophenone to amine-functionalized cellulose via an amide bond. (2) The binding of dirhodium complexes on functionalized porous silica material has been studied by DNP enhanced 15N and 13C solid-state NMR that prove the binding of the complex in axial position via an amine coordination and via the carboxy function in equatorial position. The number of active sites was quantified by 19F MAS NMR and correlates well with the data from catalytic experiments of the model cyclopropanation of styrene. A mechanism for the immobilization of the complex has been proposed based on thermodynamic data from DFT calculations and is in excellent agreement with the obtained results from solid-state NMR experiments. (3) Multinuclear Solid-state NMR is evaluated as an efficient tool to identify the composition of commercially available epoxy raisin-based thermosets doped with phosphorous containing flame retardants. (4) The DNP methodology was extended to novel radicals with high efficiency to generate enhancement as well as to systems containing immobilized radicals that can be used for solvent free DNP experiments. (5) Selective DNP signal enhancement has been introduced for polymer functionalized cellulose/paper substrates as powerful tool to separate signals of the polymer from the cellulose/paper material by tuning the DNP sample preparation. This approach is applied to identify the structure of the shell independent of the core in complex core-shell nanoparticle architectures.
Publications
- Coherent manipulation of nonthermal spin order in optical nuclear polarization experiments. J. Chem. Phys. (2017), 146, 114501
G. Buntkowsky, K.L. Ivanov, H. Zimmermann, H.-M. Vieth
(See online at https://doi.org/10.1063/1.4976990) - Dynamic Nuclear Polarization Signal Amplification as a Sensitive Probe for Specific Functionalization of Complex Paper Substrates. J.Phys.Chem. C, 2017, 121, 3896-3903
Gutmann, T.; Kumari, B.; Zhao, L.; Breitzke, H.; Schöttner, S.; Rüttiger, C.; Gallei, M.
(See online at https://doi.org/10.1021/acs.jpcc.6b11751) - Revealing Structure Reactivity Relationships in heterogenized Dirhodium Catalysts by Solid State NMR Techniques. J.Phys.Chem. C, (2017), 121, 17409–17416
J Liu, P. Braga-Groszewicz, Q. Wen, A.S. Lilly Thankamony, B.Zhang, U. Kunz, G. Sauer, Y. Xu, T. Gutmann, G. Buntkowsky
(See online at https://doi.org/10.1021/acs.jpcc.7b06807) - Thermo-reversible self-assembly of perfluorinated corecoronas cellulose-nanoparticles in dry state. Advanced Materials, (2017), 1702473
Y. Wang, P.B. Groszewicz, S. Rosenfeldt, H. Schmidt, C. A. Volkert, P. Vana, T. Gutmann, G. Buntkowsky, K. Zhang
(See online at https://doi.org/10.1002/adma.201702473) - Efficient, self‐terminating isolation of cellulose nanocrystals via periodate oxidation in Pickering emulsions. Chem.Sus.Chem. (2018), 11, 3581-3585
P. Liu, B. Pang, L. Tian, T. Schäfer, T. Gutmann, H. Liu, C. A. Volkert, G. Buntkowsky, K. Zhang
(See online at https://doi.org/10.1002/cssc.201801678) - Gallei, M., Preceramic Core-Shell Particles for the Preparation of Hybrid Colloidal Crystal Films by Melt- Shear Organization and Conversion into Porous Ceramics. Materials & Design, 2018, 160, 926-935
Vowinkel, S.; Boehm, A.; Schäfer, T.; Gutmann, T.; Ionescu, E.; Gallei, M.
(See online at https://doi.org/10.1016/j.matdes.2018.10.032) - Selective DNP Signal Amplification to Probe Structures of Core–Shell Polymer Hybrid Nanoparticles.; J.Phys.Chem. C, 2019, 123, 644-652
Schäfer, T.; Vowinkel, S.; Breitzke, H.; Gallei, M.; Gutmann, T.
(See online at https://doi.org/10.1021/acs.jpcc.8b07969) - Trityl-Aryl-Niroxide Based Genuinely g-Engineered Biradicals, as Studied by DNP, Multi-Frequency ESR/ENDOR, AWG Pulse MW Spectroscopy and Quantum Chemical Calculations. J.Phys.Chem.A, (2019), 123, 7507-7517
K. Sato; R. Hirao; I, Timofeev; O. Krumkacheva; E. Zaytseve; O. Rogozhnikova; V. Tormyshev; D. Trukhin; E. Bagryanskaya; T. Gutmann; V. Klimavicius; G. Buntkowsky; K. Sugisaki; S. Nakazawa; H. Matsuoka; K. Toyota; D. Shiomi; T. Takui
(See online at https://doi.org/10.1021/acs.jpca.9b07169) - Dynamics and Proton Transport in Imidazole-Doped Nanocrystalline Cellulose Revealed by High-Resolution Solid-State NMR. J.Phys.Chem.C (2020),124,18886- 18893
M. Bielejewski; M. Pinto-Salazar; L. Lindner; R. Pankiewicz; G. Buntkowsky; J.Tritt-Goc
(See online at https://doi.org/10.1021/acs.jpcc.0c04905) - N- Hydroxysuccinimide-activated esters as a functionalization agent for amino cellulose: synthesis and solid-state NMR characterization. Cellulose (2020) 27,1239- 1254
P. B. Groszewicz, P.Mendes, B. Kumari, M. Biesalski, T. Gutmann, G. Buntkowsky
(See online at https://doi.org/10.1007/s10570-019-02864-5) - Solid-State NMR as versatile tool to identify the main chemical components of epoxy-based thermosets. ACS Omega (2020), 5, 5412-5420
T. Schäfer, G. Buntkowsky, T. Gutmann
(See online at https://doi.org/10.1021/acsomega.9b04482) - Direct Observation of Carbonate Formation in Partly Hydrated Tricalcium Silicate by DNP Enhanced NMR Spectroscopy. J. Phys.Chem. C, (2021), 125, 7321–7328
V. Klimavicius, H. Hilbig, T. Gutmann, G. Buntkowsky
(See online at https://doi.org/10.1021/acs.jpcc.0c10382) - Mechanism of Heterogenization of Dirhodium Catalysts: Insights from DFT calculations. Inorganic Chemistry (2021)
Pietruschka, D.; Kumari, B.; Buntkowsky, G.; Gutmann, T. Mollenhauer, D.
(See online at https://doi.org/10.1021/acs.inorgchem.0c03712) - Surface reactions of ammonia on ruthenium nanoparticles revealed by 15N and 13C solid-state NMR. Catal. Sci. Technol., 2021
Rothermel, N., Limbach, H.-H., del Rosal, I., Poteau, R., Mencia, G., Chaudret, B., Buntkowsky, G., Gutmann, T.
(See online at https://doi.org/10.1039/D0CY02476G)
