Article
Chemistry, Analytical
Joshua W. Peterson, Scott R. Burt, Yu Yuan, James K. Harper
Summary: Nuclear magnetic resonance (NMR) studies involving O-17 are becoming increasingly important, but the high cost of (H2O)-O-17 limits its use. A recent study proposed a low-cost distillation scheme to produce large quantities of (H2O)-O-17. This article describes an alternative reaction scheme to measure O-17 water, which is fast, produces only one O-17 product, and requires no cleanup step. The accuracy of the C-13 NMR analysis is high and accessible to most NMR spectroscopists.
ANALYTICAL CHEMISTRY
(2022)
Article
Chemistry, Physical
Hans J. Jakobsen, Henrik Bildsoe, Martin Bondesgaard, Bo B. Iversen, Michael Brorson, Flemming H. Larsen, Zhehong Gan, Ivan Hung
Summary: Solid-state Mo-95 NMR experiments were conducted on four different MoS2 materials at different magnetic field strengths, revealing the dominance of chemical shift anisotropy relaxation mechanism and the delocalization of MoS2 band gap electrons in lattice-layer structures. The studies showed that Mo-95 spin-lattice relaxation time decreased with increasing magnetic field strength and decreasing number of 2H-MoS2 layers, leading to useful NMR spectra acquisition for MoS2 nanomaterials.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Biochemistry & Molecular Biology
Daniel Sieme, Christian Griesinger, Nasrollah Rezaei-Ghaleh
Summary: Heparins and heparan sulfate polysaccharides play important roles in cell-to-matrix and cell-to-cell signaling processes. In this study, a Na-23 NMR-based competition assay was developed to monitor metal ion binding to heparin and the release of sodium ions. The results showed that there are at least two metal ion-binding sites on heparin, potentially undergoing dynamic exchange.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Chemistry, Physical
Ivan Hung, Eric G. Keeler, Wenping Mao, Peter L. Gor'kov, Robert G. Griffin, Zhehong Gan
Summary: This study addresses the challenges of low sensitivity, low resolution, and large quadrupolar couplings in the NMR study of oxygen by employing efficient isotopic labeling, high magnetic fields, fast sample spinning, and H-1 detection. Oxygen sites specific to each amino acid residue are observed through multidimensional experiments. The use of cross-polarization at high sample spinning frequencies enables efficient C-13<->O-17 polarization transfer. Results show that using O-17 for initial polarization provides better sensitivity per unit time compared to H-1.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Review
Chemistry, Multidisciplinary
Guodong Qi, Qiang Wang, Jun Xu, Feng Deng
Summary: This tutorial review focuses on the fundamentals and state-of-the-art applications of solid-state NMR correlation techniques in the field of heterogeneous catalysis, highlighting its important role in structural characterization of catalytic materials and relevant studies on synthesis, synergistic catalysis, host-guest interactions, and reaction mechanisms. Various correlation NMR methods have been employed to address challenging issues in heterogeneous catalysis, with promising applications and potential developments of solid-state NMR correlation spectroscopy in catalytic materials.
CHEMICAL SOCIETY REVIEWS
(2021)
Article
Chemistry, Analytical
Ana Belen Ruiz-Muelle, Paula Garcia Moreno, Ignacio Fernandez
Summary: NMR offers unique potential for selective excitation of specific nuclei and avoiding matrix effects; Quantitative N-14 qNMR spectroscopy is a robust method for determining choline in various matrices; Study of ion pairing of choline bitartrate in aqueous solution and fast, reliable quantification of choline were also provided.
Article
Chemistry, Multidisciplinary
Kuizhi Chen, Zhehong Gan, Sarah Horstmeier, Jeffery L. White
Summary: The structure of aluminum-containing moieties in and within zeolite H-ZSM-5 catalysts is influenced by various factors and can be analyzed using Al-27 NMR data. Nonframework aluminum species can be detected post hydrothermal exposure and distinguished from partially coordinated framework sites. Hydration impacts the appearance and interpretation of conventional Al-27 spectra, and initial assessment of aluminum sites in high-Al content MFI catalysts can guide reaction conditions.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Physical
Diego Carnevale, Georges Mouchaham, Sujing Wang, Mathieu Baudin, Christian Serre, Geoffrey Bodenhausen, Daniel Abergel
Summary: In this study, the investigation of O-17 resonances in zirconium-oxo clusters within porous Zr carboxylate MOFs was carried out using DNP-enhanced MAS NMR spectroscopy. Through high-resolution spectral analysis, O-17 sites were successfully resolved with the assistance of DFT calculations and cross-polarization techniques.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Tongyao Zhao, Lili Hu, Jinjun Ren
Summary: The presence of Ba2LaF7 crystals facilitates the polymerization of the phosphorus glass network, with Er3+ ions still present in the glass phase even after crystal formation, as indicated by the evolution of the P-31 spectrum.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
Leo W. Gordon, Ankur L. Jadhav, Mikhail Miroshnikov, Theresa Schoetz, George John, Robert J. Messinger
Summary: Rechargeable aluminum-organic batteries are considered as a promising energy storage technology due to the earth abundance and safety of aluminum metal, as well as the sustainability and tunability of organic molecules. However, the mechanisms of charge storage in these batteries are not well understood. In this study, multidimensional solid-state NMR spectroscopy and electrochemical methods are used to experimentally elucidate the ionic and electronic charge storage mechanism in an aluminum-organic battery. The results provide insights into the reversible electrochemical reactions and charge compensation mechanisms in these batteries.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Analytical
Ana Belen Ruiz-Muelle, Concepcion Diaz Navarro, Ignacio Fernandez
Summary: A qQNMR methodology using nitrogen-14 as the quadrupolar nucleus has been introduced for the determination and quantification of L-carnitine in food supplements. The method was validated at seven concentration levels with high precision and robustness, showing low limits of detection and quantification. The absence of matrix effect is a notable feature of this method.
JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
(2022)
Article
Chemistry, Physical
Vinicius Martins, Bryan E. G. Lucier, Kuizhi Chen, Ivan Hung, Zhehong Gan, Christel Gervais, Christian Bonhomme, Heng-Yong Nie, Wanli Zhang, Yining Huang
Summary: Porous metal-organic frameworks (MOFs) have diverse applications in various fields, and post synthetic modification (PSM) approaches can enhance their properties. In this study, high-field solid-state NMR techniques were used to gain molecular-level insights into a prototypical aluminum MOF and its interactions with metal guests. The results provide detailed information about the oxygen environment, intermolecular interactions, and host-guest connectivity in the MOF.
CHEMISTRY OF MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Zhenchao Zhao, Dong Xiao, Kuizhi Chen, Rui Wang, Lixin Liang, Zhengmao Liu, Ivan Hung, Zhehong Gan, Guangjin Hou
Summary: The surface structures of gamma-Al2O3 and Al(V)-rich Al2O3 nanosheets (Al2O3-NS) have been compared and investigated using high-field solid-state NMR, revealing important differences which may aid in understanding the structure-function relationship of alumina.
ACS CENTRAL SCIENCE
(2022)
Article
Chemistry, Physical
Racha Bayzou, Julien Trebosc, Ivan Hung, Zhehong Gan, Andrew Rankin, Olivier Lafon, Jean-Paul Amoureux
Summary: The indirect NMR detection of quadrupolar nuclei in solids can be achieved through the T-HMQC sequence incorporating the TRAPDOR dipolar recoupling. Numerical simulations of spin dynamics show that the fastest coherence transfer in the T-HMQC scheme is achieved when using the highest compatible rf field. Furthermore, the indirect detection of triple-quantum coherences improves the spectral resolution for spin-3/2 quadrupolar nuclei.
SOLID STATE NUCLEAR MAGNETIC RESONANCE
(2022)
Article
Chemistry, Physical
Rick W. Dorn, Bradley J. Ryan, Sujeewa N. S. Lamahewage, Mark V. Dodson, Jeremy B. Essner, Rana Biswas, Matthew G. Panthani, Aaron J. Rossini
Summary: 1H{35Cl} and 29Si{35Cl} solid-state NMR experiments confirm the presence of chlorinated Si atoms within Si-NS. Density functional theory calculations show that the band gap of Si-NS can be adjusted by modifying the terminal atoms or functional groups.
CHEMISTRY OF MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Helena Keil, Karsten Sonnenberg, Carsten Mueller, Regine Herbst-Irmer, Helmut Beckers, Sebastian Riedel, Dietmar Stalke
Summary: Several publications have discussed the bonding concepts in polyhalides theoretically, focusing on the symmetrical trichlorine monoanion. However, only asymmetric trichlorine anions have been reported so far, except in matrix-isolation studies. This study analyzes trichlorine monoanions in different compounds and provides insight into their structures through X-ray structures, charge density analyses, and quantum-chemical calculations.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Applied
Dominik Ruhr, Michael John, Annette Reiche
Summary: Experimental study showed that approximately 50% of BDDE molecules effectively cross-link, and there is a direct correlation between the degree of cross-linking and the decomposition temperature of the cellulose membranes.
CARBOHYDRATE POLYMERS
(2021)
Article
Chemistry, Multidisciplinary
Florian Grimm, Jasmin Rehman, Stefan Stoldt, Taukeer A. Khan, Jan Gero Schlotel, Shamil Nizamov, Michael John, Vladimir N. Belov, Stefan W. Hell
Summary: In this study, new rhodamine dyes were successfully synthesized through a series of reactions, and conjugates of these dyes with small molecules were used for specific labeling of organelles and components of the cytoskeleton in living cells. These dyes were also combined with fluorescent probes such as 610CP and SiR, and applied in two-color STED microscopy.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Simon Hanio, Jonas Schlauersbach, Bettina Lenz, Franziska Spiegel, Rainer A. Boeckmann, Ralf Schweins, Ivo Nischang, Ulrich S. Schubert, Sebastian Endres, Ann-Christin Poeppler, Ferdinand P. Brandl, Theo M. Smit, Karl Kolter, Lorenz Meinel
Summary: The study investigated the impact of Perphenazine concentrations on bile colloids using various techniques, revealing that Perphenazine affects the structure and thermodynamics of the colloids in a concentration-dependent manner. Despite inducing dynamic changes in the colloids, they effectively maintained stable levels of free Perphenazine throughout the tested concentration range.
Article
Chemistry, Multidisciplinary
Guido Schroer, Valerie Toussaint, Stephanie Bachmann, Ann-Christin Poeppler, Christian Henning Gierlich, Irina Delidovich
Summary: The transition from fossil to renewable feedstocks demands new efficient processes for economically viable production of biomass-derived commodities and fine chemicals. This study focuses on the synthesis and testing of cross-linked p-vinylphenylboronate polymers for the separation of various compounds obtained during biomass processing, showing promising potential for efficient separation of substrates with significantly different complexation constants.
Article
Biochemistry & Molecular Biology
Lukas Hahn, Emine Karakaya, Theresa Zorn, Benedikt Sochor, Matthias Maier, Philipp Stahlhut, Stefan Forster, Karl Fischer, Sebastian Seiffert, Ann-Christin Poeppler, Rainer Detsch, Robert Luxenhofer
Summary: This study presents a novel ABA-type triblock copolymer hydrogel with excellent physical properties and biocompatibility, suitable for various applications such as bioprinting. The hydrogel exhibits rapid thermoresponsive inverse gelation, solid-like properties, and good cell viability, making it a promising material for tissue engineering and drug delivery.
Article
Chemistry, Inorganic & Nuclear
Tim Kuellmey, Mohammad R. Ghazanfari, Robert Burda, Elena Voloshina, Clara A. von Randow, Friederike Fuss, Moritz Liesegang, Beate Paulus, Ann-Christin Poeppler, Guenther Thiele
Summary: Anionic lithium-containing species known as inolithates, comprising [LiCl2](-) and [Li2Cl3](-) polyanions, have been isolated for the first time from ionothermal reactions. These compounds are of interest for potential applications in electrochemical lithium-based systems and are considered intermediates in ionic liquid applications. The structures and formation mechanism of inolithates are discussed in depth, highlighting the absence of covalent bonding in the anionic moieties.
INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Sebastian Scheidel, Laurina Oestreicher, Isabelle Mark, Ann-Christin Poeppler
Summary: Solid-state nuclear magnetic resonance (NMR) is a versatile tool for studying the structures and phase transitions of pharmaceutical molecules. This paper summarizes unexpected structural rearrangements and phase transitions that can occur under magic angle spinning (MAS) conditions. It demonstrates the capability of solid-state NMR experiments, particularly H-1-C-13 frequency-switched Lee-Goldburg heteronuclear correlation (FSLG HETCOR)/MAS NMR experiments, to detect subtle molecular-level changes that cannot be observed by conventional 1D NMR experiments or X-ray powder diffraction. The study also shows that MAS can induce crystalline-to-crystalline phase transitions in the presence of polymorphic impurities.
MAGNETIC RESONANCE IN CHEMISTRY
(2022)
Article
Chemistry, Inorganic & Nuclear
Sheida Rajabi, Franziska Ruettger, Jana Luecken, Sebastian Dechert, Michael John, Franc Meyer
Summary: Two mononuclear ruthenium(II) complexes with dianionic {N-4} ligands and axial pyridines were prepared and characterized structurally. The redox properties of the complexes were investigated electrochemically, and their potential as water oxidation catalysts was tested using cerium ammonium nitrate at pH 1.0. Complex 1 underwent degradation, likely due to ligand oxidation, while complex 2 exhibited higher stability and efficiency in water oxidation reactions.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Jarno Riefer, Ludwig Zapf, Jan A. P. Sprenger, Raphael Wirthensohn, Sebastian Endres, Ann-Christin Poeppler, Marcus Gutmann, Lorenz Meinel, Nikolai V. Ignat'ev, Maik Finze
Summary: This article describes the synthesis and characterization of low-viscosity room-temperature ionic liquids (RTILs) and [BnPh3P](+) salts with various cyano(fluoro)borate anions. The RTILs were obtained with high yield and purity, allowing their application in electrochemical devices. The physicochemical properties of the RTILs were assessed, including thermal stability, melting and freezing behavior, density, electrochemical stability, dynamic viscosity, specific conductivity, ion diffusivity, and cytotoxicity.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Franziska Ruettger, Tim Patten, Johannes Kretsch, Anna Krawczuk, Dietmar Stalke, Michael John
Summary: A new NMR method utilizing Li-7 residual quadrupolar couplings (RQCs) in a stretched polystyrene (PS) gel is proposed for the structure determination of lithium compounds under solution-like conditions, by comparing the experimental RQCs with those predicted from crystal or DFT-derived model structures. This method was successfully applied to five lithium model complexes, revealing the monomeric structures of four complexes with Li coordinated fourfold by two additional THF molecules, and the limited space for an additional THF molecule in one complex due to bulky tBu groups.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Pharmacology & Pharmacy
Lena Scheller, Stephanie Bachmann, Theresa Zorn, Simon Hanio, Uwe Gbureck, Dimitrios Fatouros, Ann-Christin Poppler, Lorenz Meinel
Summary: In this study, the solidification of drug-loaded microemulsion preconcentrates with the acid-sensitive metal-organic framework ZIF-8 was detailed using various analytical techniques. Nile Red, Vitamin K1, and Lumefantrine were used as model compounds to analyze the adsorption and desorption dynamics. The loaded preconcentrates and drugs were successfully preserved in the crystal structure of ZIF-8, which could be pressed into tablets or 3D-printed into oral dosage forms. The stimuli-responsive metal organic frameworks have the potential to form colloidal microemulsions in solid dosage forms for oral delivery of lipid-based formulations.
EUROPEAN JOURNAL OF PHARMACEUTICS AND BIOPHARMACEUTICS
(2023)
Article
Medicine, Research & Experimental
Jonas Schlauersbach, Dominic Werthmueller, Cornelius Harlacher, Bruno Galli, Simon Hanio, Bettina Lenz, Sebastian Endres, Ann-Christin Poppler, Oliver Scherf-Clavel, Lorenz Meinel
Summary: Bile solubilization and apparent solubility play a crucial role in the bioavailability of oral drugs. The interaction between drugs and bile is important for successful formulation. In the case of naporafenib, its solubility significantly improved with RH40 and Eudragit E in PBS and PBS with bile components, but not with HPC. H-1 and 2D H-1-H-1 nuclear magnetic resonance spectroscopy confirmed the interaction of naporafenib, Eudragit E, and RH40 with bile. Flux across artificial membranes was reduced by Eudragit E, while HPC stabilized naporafenib's supersaturation. These findings correlated with the pharmacokinetics in beagle dogs, where HPC showed favorable results.
MOLECULAR PHARMACEUTICS
(2023)
Article
Chemistry, Applied
Layla Engelhardt, Tobias Pohnl, Mohammad Alhussein, Michael John, Susanne Neugart
Summary: Amaranthus L. leaves are rich in secondary plant metabolites, with high amounts of hydroxycinnamic glucaric and-isocitric acids. They also exhibit antioxidant activity similar to 5-caffeoylquinic acid. The antioxidant activity is influenced more by the phenolic and ascorbic acid concentrations rather than the species of Amaranthus L. Household cooking may reduce antioxidant activity, while leaching into cooking water has negligible effects. Baking Amaranthus L. into a wheat-dough-matrix may result in lower phenolic concentrations due to phenol-protein binding and thermal degradation.
Article
Chemistry, Inorganic & Nuclear
Stefan Repp, Kim Lara Junginger, Dieter Sorsche, Theresa Zorn, Ann-Christin Poeppler, Yuji Kikukawa, Yoshihito Hayashi, Carsten Streb
Summary: The self-assembly of polyoxometalates (POMs), molecular metal oxides, can be controlled by internal or external templates. This study explores how the interaction between internal templates (halides, oxoanions) and external organic templates (protonated cyclene species) affects the self-assembly of a model polyoxovanadate cluster. Crystallographic analyses, spectroscopic studies, and V-51 NMR spectroscopy provide insights into the formation of an intermediate vanadate species during the process. These findings contribute to the development of template-driven synthetic chemistry of polyoxovanadates.
DALTON TRANSACTIONS
(2023)
