A5083954031- Laser-Matter Interactions and Applications
- Advanced Chemical Physics Studies
- Spectroscopy and Quantum Chemical Studies
- Mass Spectrometry Techniques and Applications
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Advanced Fiber Laser Technologies
- Atomic and Molecular Physics
- Laser-induced spectroscopy and plasma
- Porphyrin and Phthalocyanine Chemistry
- Photochemistry and Electron Transfer Studies
- Gold and Silver Nanoparticles Synthesis and Applications
- Metal complexes synthesis and properties
- Electrocatalysts for Energy Conversion
- Asymmetric Hydrogenation and Catalysis
- Laser-Plasma Interactions and Diagnostics
- Quantum optics and atomic interactions
- Catalysis and Oxidation Reactions
- CO2 Reduction Techniques and Catalysts
- Spectroscopy Techniques in Biomedical and Chemical Research
- Metalloenzymes and iron-sulfur proteins
- Plasmonic and Surface Plasmon Research
- Nanocluster Synthesis and Applications
- Catalytic C–H Functionalization Methods
- Luminescence and Fluorescent Materials
Friedrich Schiller University Jena
2016-2025
Helmholtz Institute Jena
2015-2024
Fraunhofer Institute for Applied Optics and Precision Engineering
2021-2024
Leibniz Institute of Photonic Technology
2022-2023
Technische Universität Berlin
2021
Missouri University of Science and Technology
2021
Kansas State University
2021
Physikalisch-Technische Bundesanstalt
2021
TU Wien
2008-2015
Jilin University
2014
Acetylene's scission visualized by selfie Can molecules take pictures of themselves? That is more or less the principle underlying laser-induced electron diffraction (LIED): A laser field strips an from a molecule and then sends it back to report on structure remaining ion. Wolter et al. applied this technique acetylene track cleavage its C–H bond after double ionization (see Perspective Ruan). They imaged full also distinguished rapid dissociative dynamics when was oriented parallel rather...
Control over various fragmentation reactions of a series polyatomic molecules (acetylene, ethylene, 1,3-butadiene) by the optical waveform intense few-cycle laser pulses is demonstrated experimentally. We show both experimentally and theoretically that responsible mechanism inelastic ionization from inner-valence molecular orbitals recolliding electron wave packets, whose recollision energy in ionizing strongly depends on waveform. Our work demonstrates an efficient selective way...
We experimentally and theoretically demonstrate a self-referenced wave-function retrieval of valence-electron wave packet during its creation by strong-field ionization with sculpted laser field. Key is the control over interferences arising at different time scales. Our work shows that measurement subcycle electron wave-packet interference patterns can serve as tool to retrieve structure dynamics cloud in atoms on sub-10-as scale.
The straightforward synthesis of a urea polymer network is presented. Commercially available monomers are polymerized using light-induced polymerization, resulting in networks crosslinked by hindered molecules. These moieties reversible and, thus, can be converted into the starting compounds (that is, isocyanate and amine) simple thermal treatment. This process monitored differential scanning calorimetry as well Raman infrared spectroscopy. Furthermore, self-healing ability these...
The generation of higher-order harmonic radiation originating from the interaction intense laser pulses with matter is typically described semiclassically: While electronic structure and dynamics quantum mechanically, light field classically---and accordingly generated radiation. However, pioneering experiments on optical properties high-order (HHG) in atomic gases group P. Tzallas [I. Gonoskov et al., Sci. Rep. 6, 32821 (2016) N. Tsatrafyllis Nat. Commun. 8, 15170 (2017)], theoretical...
The conversion of the thiols 4-aminothiophenol (ATP) and 4-nitrothiophenol (NTP) can be considered as one standard reactions plasmon-induced catalysis thus has already been subject numerous studies. Currently, two reaction pathways are discussed: describes a dimerization starting material yielding 4,4'-dimercaptoazobenzene (DMAB), while in second pathway, it is proposed that NTP reduced to ATP HCl solution. In this combined experimental theoretical study, we disentangled involved...
Experimental evidence of extremely high spatial resolution tip-enhanced Raman scattering (TERS) has been recently demonstrated. Here, we present a full quantum chemical description (at the density functional level theory) non-resonant effects on spectrum an adenine molecule mapped by tip, modeled as single silver atom or small cluster. We show pronounced changes in pattern and its intensities depending conformation nanoparticle-substrate system, concluding that contribution TERS can be sub-nm range.
We investigate the possibility of using molecular alignment for controlling relative probability individual reaction pathways in polyatomic molecules initiated by electronic processes on few-femtosecond time scale. Using acetylene as an example, it is shown that aligning axis with respect to polarization direction ionizing laser pulse does not only allow us enhance or suppress overall fragmentation yield a certain channel but, more importantly, determine starting from same parent ion. show...
We analyze the formation of low-energy structure (LES) in above-threshold ionization spectra strong-field by midinfrared laser pulses using both quasiclassical and quantum approaches. show this to be largely classical origin, resulting from a two-dimensional focusing energy--angular-momentum plane dynamics presence atomic potential. The latter is shown cause LES even absence long-range Coulomb tail. peak at low energy strongly correlated with high angular momenta photoelectrons. Quantum...
The thermally induced self-healing mechanisms in metallopolymers based on bisterpyridine complexes of iron(II) sulfate and cadmium(II) bromide, respectively, were studied by means combined quantum mechanical/molecular mechanical (QM/MM) simulations Raman spectroscopy. Two possible healing schemes, one a decomplexation the cross-linking second relying dissociation ionic clusters, have been addressed. Temperature-dependent spectroscopy displayed bathochromic shifts intensity pattern upon...
The π-extended ligand of a ruthenium complex stores two photo-generated electrons, mimicking key step in photosynthesis.
Heteroleptic Cu(i) complexes are a promising alternative towards traditional Ru(ii) photosensitizers. In particular, of the type [Cu(P^P)(N^N)]+, where N^N represents diimine and P^P bulky diphosphine ligand, already successfully applied for photocatalysis, organic light-emitting diodes or dye-sensitized solar cells. Therefore, this study aims systematic comparison three novel heteroleptic compounds, composed xantphos (xant) as ligand different ligands with an extended π-system in backbone,...
Significance Laser-induced electron diffraction is a molecular-scale microscopy that captures clean snapshots of molecule’s geometry with subatomic picometer and attosecond spatiotemporal resolution. We induce unambiguously identify the stretching bending linear triatomic molecule following excitation to an excited electronic state bent stretched geometry. show we can directly retrieve structure electronically molecules otherwise possible through indirect retrieval methods such as pump–probe...
Abstract Predicting the energetics of chemical transformations requires localizing stationary points on a potential energy surface. While educts and products reaction may be known, transition state optimization is challenging as good guesses unavailable. Extending point searches to excited leads additional difficulties several states close in energy, requiring efficient tracking. Here, we report implementation pysisyphus, an external optimizer, that allows localization not only ground but...
Tip-enhanced Raman spectroscopy (TERS) is a valuable method for surface analysis with nanometer to angstrom-scale resolution; however, the accurate simulation of particular TERS signals remains computational challenge. We approach this challenge by combining two main contributors plasmon-enhanced and high resolution in TERS, particular, electromagnetic chemical effect, into one quantum mechanical simulation. The effect describes sample's interaction strong, highly localized, inhomogeneous...
Abstract When a chemical bond is broken, the molecular structure undergoes transformation. An ideal experiment should probe change in electronic and nuclear simultaneously. Here, we present method for simultaneous time-resolved imaging of electron dynamics by combining Coulomb explosion with strong-field photoelectron momentum imaging. We study dissociative photoionization H 2 N O using photoion-photoelectron coincidence spectroscopy. The measured delay-dependent kinetic energy release...
We revisit the theoretical description of $F$ color center in lithium fluoride employing advanced complementary ab initio techniques. compare results from periodic supercell calculations involving density-functional theory (DFT) and post-DFT techniques with those embedded-cluster approach quantum-chemical many-electron wave-function These alternative approaches yield good agreement each other experimental data provided that correlation effects are properly taken into account.
Synthetic models of the active site [FeFe]-hydrogenase containing naphthalene monoimide (NMI) peri-substituted dichalcogenides as bridging linkers have been prepared and characterized using different spectroscopic methods. The influence imide functionality chalcogen atoms on redox properties catalytic behaviour complexes 7-10 was studied cyclic voltammetry. results revealed that has improved chemical stability reduced species replacement S by Se caused a cathodic shift in oxidation peaks....
The thermally healable polymer P(LMA-co-FMA-co-MIMA) has been studied by temperature-dependent FT-Raman spectroscopy, two-dimensional Raman correlation analysis and density functional theory (DFT) calculations. To the best of our knowledge this study reports for first time on investigation a self-healing means techniques. synchronous spectrum reveals that spectrally overlapping C[double bond, length as m-dash]C stretching vibrations at 1501, 1575, 1585 1600 cm(-1) are perfect marker bands to...
The present computational study aims at unraveling the competitive photoinduced electron transfer (ET) kinetics in a supramolecular photocatalyst model. Detailed understanding of fundamental processes is essential for design novel photocatalysts scope solar energy conversion that allows unidirectional ET from light-harvesting photosensitizer to catalytically active site. Thus, photophysics and photochemistry bimetallic complex RuCo, [(bpy)2RuII(tpphz)CoIII(bpy)2]5+, where excitation...
Lately, experimental evidence of unexpectedly extremely high spatial resolution tip-enhanced Raman scattering (TERS) has been demonstrated. Theoretically, two different contributions are discussed: an electromagnetic effect, leading to a spatially confined near field due plasmonic excitations; and the so-called chemical effect originating from locally modified electronic structure molecule close proximity system. Most theoretical efforts have concentrated on contribution or in case...
The high natural abundance of aluminium makes the respective fluorophores attractive for various optical applications, but photoluminescence quantum yields above 0.7 have yet not been reported solutions complexes. In this contribution, a dinuclear aluminium(III) complex featuring enhanced properties is described. Its facile one-pot synthesis originates from readily available precursor and trimethyl aluminium. solution, exhibits an unprecedented yield near unity (Φ