A5025144511- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Metal-Organic Frameworks: Synthesis and Applications
- Crystallography and molecular interactions
- Molecular Sensors and Ion Detection
- Advanced NMR Techniques and Applications
- Supramolecular Chemistry and Complexes
- Covalent Organic Framework Applications
- NMR spectroscopy and applications
- Advanced Chemical Physics Studies
- Chemical Synthesis and Reactions
- Radio Frequency Integrated Circuit Design
- Medical Imaging Techniques and Applications
- Microwave and Dielectric Measurement Techniques
- Electrostatics and Colloid Interactions
- Biochemical and Structural Characterization
- Chemical Synthesis and Characterization
- Muon and positron interactions and applications
- Organophosphorus compounds synthesis
- Atomic and Subatomic Physics Research
- Bone health and treatments
- Metal and Thin Film Mechanics
- Carbohydrate Chemistry and Synthesis
- Geology and Paleoclimatology Research
- Hydrogen embrittlement and corrosion behaviors in metals
Federal Institute For Materials Research and Testing
2022-2023
Heinrich Heine University Düsseldorf
2013-2020
Technical University of Darmstadt
2012
Friedrich Schiller University Jena
2011
Helmholtz Institute Jena
2011
Caged supramolecular systems are promising hosts for guest inclusion, separation, and stabilization. Well-studied examples mainly metal-coordination-based or covalent architectures. An anion-coordination-based cage that is capable of encapsulating halocarbon guests reported the first time. This A4L4-type (A=anion) tetrahedral cage, [(PO4)4L4](12-), assembled from a C3-symmetric tris(bisurea) ligand (L) phosphate ion (PO4(3-)), readily accommodates series quasi-tetrahedral halocarbons, such...
Characterization of polyacrylamide hydrogels with dextran host molecules using four complementary methods.
The first polyurethane material which is microporous (BET surface area of 312 m(2) g(-1)) prepared by solvothermal synthesis and acts as highly efficient recyclable heterogeneous catalyst in the Knoevenagel condensation showing size selectivity, Henry reaction substrate selectivity under mild conditions.
A catalyst-free Schiff base reaction was applied to synthesize two imine-linked covalent organic frameworks (COFs). The condensation of 1,3,5-tris-(4-aminophenyl)triazine (TAPT) with 4,4'-biphenyldicarboxaldehyde led the structure HHU-COF-1 (HHU = Heinrich-Heine University). fluorinated analog HHU-COF-2 obtained 2,2',3,3',5,5',6,6'-octafluoro-4,4'-biphenyldicarboxaldehyde. Solid-state NMR, infrared spectroscopy, X-ray photoelectron and elemental analysis confirmed successful formation...
Abstract Caged supramolecular systems are promising hosts for guest inclusion, separation, and stabilization. Well‐studied examples mainly metal‐coordination‐based or covalent architectures. An anion‐coordination‐based cage that is capable of encapsulating halocarbon guests reported the first time. This A 4 L ‐type (A=anion) tetrahedral cage, [(PO ) ] 12− , assembled from a C 3 ‐symmetric tris(bisurea) ligand ( phosphate ion (PO 3− ), readily accommodates series quasi‐tetrahedral...
Abstract In this paper a possible explanation for an unexpected ortho/para- water ratio in the gas clouds of comets is given. The description based on quantum-mechanical density matrix formalism and spin temperature concept. Only nuclear system treated quantum-mechanically. Employing model four system, created by two nearest neighbour molecules, eigenstates their dynamics under influence mutual dipolar interactions are studied. It shown that fast conversion between ortho - para -states...
Der C3-symmetrische Tris(diharnstoff)-Ligand L bildet gemeinsam mit PO43−-Ionen den tetraedrischen Käfig [(PO4)4L4]12−. Die an vier Ecken dieses Käfigs bilden jeweils 12 NH⋅⋅⋅O-Wasserstoffbrücken 6 Harnstoffgruppen. Mit SO42−-Ionen schließt sich zu dem beispiellosen windradförmigen Dreikernkomplex [(SO4)3L2]6− zusammen (siehe Bild).
Abstract By tuning the length and rigidity of spacer bis(biurea) ligands L, three structural motifs A 2 L 3 complexes (A represents anion, here orthophosphate PO 4 3− ), namely helicate, mesocate, mono‐bridged motif, have been assembled by coordination ligand to phosphate anion. Crystal structure analysis indicated that in complexes, each ions is coordinated twelve hydrogen bonds from six surrounding urea groups. The anion properties solution also studied. results further demonstrate...
The (2)H solid-state NMR spectra of the transition metal complexes Tp*RuD(THT)(2) (1a), Tp*RuD(D(2))(THT) (1b), Tp*RuD(D(2))(2) (1c), Cp*RuD(3)(PPh(3)) (2) and RuD(2)(eta(2)-D(2))(2)(PCy(3))(2) (3) have been measured in a wide temperature range. These compounds were chosen as potential model systems for hydrogen surface species Ru-nanoparticles. deuterium quadrupolar coupling constants Q(cc) asymmetry parameters extracted by line-shape analysis. values deuterons bound to vary between 13 kHz...
Abstract The 2 H-NMR solid echo spectra of biphenyl molecules as guests in the mesopores neat and silylated SBA-15 have been measured a function temperature. At low temperatures typical H-Pake patterns with parameters (Q zz =132 kHz, corresponding to Q cc =176 kHz) ( η =0.04) are observed. All samples exhibit strong reduction melting point from bulk value 342.4 K values between 222 229 K, depending on both pore diameter surface state glass like behavior regime. Employing Roessler two-phase...
Abstract α‐Peptoids, or N ‐substituted glycine oligomers, are an important class of peptidomimetic foldamers with proteolytic stability. Nevertheless, the presence cis / trans ‐amide bond conformers, which contribute to high flexibility α‐peptoids, is considered as a major drawback. A modified peptoid backbone improved control amide geometry could therefore help overcome this limitation. Herein, we have performed first thorough analysis folding propensities α‐aminoxy peptoids (or...
Abstract. The mutual influence of F and OH groups in neighboring sites topaz (Al2SiO4(F,OH)2) was investigated using magic angle spinning nuclear magnetic resonance (MAS NMR) Raman spectroscopy. splitting 19F 1H NMR signals, as well the band, provides evidence for hydrogen bond formation within crystal structure. Depending on whether a given group has another or fluoride its neighbor, two different constellations may form: either OH⋯O⋯HO F⋯H⋯O. proton accepting oxygen determined to be part...
GRAPHICAL ABSTRACTNMR and symmetry in bisphosphonates R1R2N-CH[P(O)(OMe)2]2All authorsNader Amadeu, Erika Bálint, Winfried Boenigk, Ádám Tajti, Gerhard Hägele http://orcid.org/0000-0001-9815-2181, Christoph Janiak & György Keglevichhttps://doi.org/10.1080/10426507.2017.1295966Published online:25 May 2017
Four bisphosphinic acids RR´C[P(CH3)(O)OH]2 are characterized by 1H, 13C{1H}, and 31P{1H} NMR data. H3C-P-C-P-CH3 skeletons give rise to [A3X]2 spin systems. Some algebraic equations derived for manual analysis of spectra. HR data heteroaromatic substituents R in RC(H)[P(CH3)(O)OH]2 reported. Dissociation constants ion-specific chemical shifts δP CH3C(OH)[P(CH3)(O)OH]2 determined controlled titrations 2a.