A5032477792- Advanced Chemical Physics Studies
- Photochemistry and Electron Transfer Studies
- Magnetism in coordination complexes
- Rare-earth and actinide compounds
- Metal-Catalyzed Oxygenation Mechanisms
- CO2 Reduction Techniques and Catalysts
- Porphyrin and Phthalocyanine Chemistry
- Magnetic properties of thin films
- Crystallography and molecular interactions
- Liquid Crystal Research Advancements
- Spectroscopy and Quantum Chemical Studies
- Advanced NMR Techniques and Applications
- Crystallography and Radiation Phenomena
- Electrochemical Analysis and Applications
- Advanced Electron Microscopy Techniques and Applications
- Chemical Thermodynamics and Molecular Structure
- Photodynamic Therapy Research Studies
- Magnetic Properties of Alloys
- Supercapacitor Materials and Fabrication
- Iron oxide chemistry and applications
- Radical Photochemical Reactions
- Synthesis and properties of polymers
- Quantum, superfluid, helium dynamics
- Topological Materials and Phenomena
- Chemical Reaction Mechanisms
Helmholtz-Zentrum Berlin für Materialien und Energie
2019-2025
University of Potsdam
2021-2022
Two‐dimensional layered double hydroxides (LDHs) are ideal candidates for a large number of (bio)catalytic applications due to their flexible composition and easy tailor properties. Functionality can be achieved by intercalation amino acids (as the basic units peptides proteins). To gain insight on functionality, we apply resonant inelastic soft x‐ray scattering near edge absorption fine structure spectroscopy CaFe LDH in its pristine form as well intercalated with proline cysteine probe...
Photosolvation is a type of ligand substitution reaction started by irradiation solution with light, triggering the replacement molecule from solvent. The excited state created through many possible pathways. For class hexacyanides groups 8 and 9 periodic table, in field band followed intersystem crossing to lowest triplet state, which we propose mediate photoaquation this complexes. In study, present time-resolved X-ray absorption data showing indications intermediate cobalt(III)...
The central moiety of porphyrins is shown to control the charge state inner complex and links it by covalent interaction peripheral substituents. This link, which enables versatile functions porphyrins, not picked up in established, reduced four orbital picture [Gouterman, J. Mol. Spectrosc., 1961, 6, 138]. X-ray absorption spectroscopy at N K-edge with density functional theory approaches gives access full electronic structure, particular π* manifold beyond Gouterman orbitals. Systematic...
Free base 5,10,15,20-tetrakis(4-carboxylatophenyl)porphyrin stands for the class of powerful porphyrin photosensitizers singlet oxygen generation and light-harvesting. The atomic level selectivity dynamic UV pump - N K-edge probe X-ray absorption spectroscopy in combination with time-dependent density functional theory (TD-DFT) gives direct access to crucial excited molecular states within unusual relaxation pathway. efficient intersystem crossing, that is El-Sayed forbidden not facilitated...
Cr(CO)
Tautomerism is one of the most important forms isomerism, owing to facile interconversion between species and large differences in chemical properties introduced by proton transfer connecting tautomers. Spectroscopic techniques are often used for characterization In this context, separating overlapping spectral response coexisting tautomers a long-standing challenge chemistry. Here, we demonstrate that using resonant inelastic X-ray scattering tuned core excited states at site exchange able...
Steric hindrance of hydration and hydrogen bond enhancement by localized charges have been identified as key factors for the massive chemical differences between hydroxypyridine/pyridone isomers in aqueous solution. While all occur mainly hydroxypyridine form gas phase, they differ more than 3 orders magnitude both their acidity tautomeric equilibrium constants upon hydration. By monitoring electronic solvation structures a function protonation state O- substitution position on pyridine...
The fluctuating hydrogen bridge bonded network of liquid water at ambient conditions entails a varied ensemble the underlying constituting H 2 O molecular moieties. This is mirrored in manifold potentials. Subnatural line width resonant inelastic X-ray scattering allowed us to quantify potential energy surfaces along symmetric normal mode and local asymmetric O–H bond coordinate up 1 1.5 Å, respectively. comparison single potentials spectroscopic signatures with phase done on various levels....
The electron–phonon scattering is one of the main microscopic mechanisms responsible for spin-flip in transient state ultrafast demagnetization. Here, we present an experimental determination temperature-dependent rate Gd. Using a static x-ray emission spectroscopy method, where reduction decay peak intensities when increasing temperature quantified, measure independently electron-phonon 5d and 4f electrons. We deduce dependence electrons, while no effect on phonon population observed Our...
Abstract While extensive work has been dedicated to the measurement of demagnetization time following an ultra-short laser pulse, experimental studies its underlying microscopic mechanisms are still scarce. In transition metal ferromagnets, one main mechanism is spin-flip conduction electrons driven by electron-phonon scattering. Here, we present original method monitor mediated scattering rate in nickel through stringent atomic symmetry selection rules x-ray emission spectroscopy....
How different microscopic mechanisms of ultrafast spin dynamics coexist and interplay is not only relevant for the development spintronics but also thorough description physical systems out-of-equilibrium. In pure crystalline ferromagnets, one main mechanism relaxation electron-phonon (el-ph) driven spin-flip, or Elliott-Yafet, scattering. Unexpectedly, recent experiments with ferro- ferrimagnetic alloys have shown sublattices. These distinct sublattice are contradictory to Elliott-Yafet...
In this work, we investigate the photo-aquation reaction of ferrocyanide anion with multi-edge picosecond soft X-ray spectroscopy. Combining information iron L-edge nitrogen and oxygen K-edges, carry out a complete characterization bonding channels in [Fe(CN)5(H2O)]3- photo-product. We observe clear spectral signatures covalent between water metal, reflecting mixing Fe dz2 orbital 3a1 4a1 orbitals H2O. Additional fingerprints related to symmetry reduction resulting loss degeneracy are also...