Refine
Has Fulltext
- yes (68)
Is part of the Bibliography
- yes (68)
Year of publication
Document Type
- Journal article (68) (remove)
Keywords
- boron (7)
- radicals (5)
- density functional calculations (4)
- chemistry (3)
- photoelectron spectroscopy (3)
- synchrotron radiation (3)
- Atomic and molecular interactions with photons (2)
- Bor (2)
- IR spectroscopy (2)
- Optical spectroscopy (2)
- Reaction kinetics and dynamics (2)
- TEM (2)
- ab initio calculations (2)
- absorption spectra (2)
- antimicrobial activities (2)
- biradicals (2)
- carbene ligands (2)
- covalent inhibitors (2)
- diborane (2)
- excited states (2)
- exciton (2)
- heterocycles (2)
- inorganic chemistry (2)
- nano rods (2)
- nanostructures (2)
- photolysis (2)
- prodrug (2)
- pyrolysis (2)
- reactive intermediates (2)
- rhodesain (2)
- self-assembly (2)
- silver (2)
- time-resolved spectroscopy (2)
- 1,4-naphthoquinone (1)
- 2Dimensionale Spektroskopie (1)
- Accumulative Femtosecond Spectroscopy (1)
- African sleeping sickness (1)
- Aqueous Solution Photochemistry (1)
- Biradikale (1)
- Bor-Carbonylkomplexe (1)
- CCD (1)
- CCD, charge-coupled device (1)
- Chemie (1)
- DFT-Rechnungen (1)
- Decarbonylierung (1)
- Diboran (1)
- Dichtefunktionalrechnungen (1)
- EDA-NOCV (1)
- EEA (1)
- Excited states (1)
- Excitons (1)
- Exziton (1)
- FL spectroscopy (1)
- Femtosecond Mid-Infrared Study (1)
- Festkörperstrukturen (1)
- Halogene (1)
- Heterocyclen (1)
- Interference microscopy (1)
- Jahn–Teller effect (1)
- Ketene (1)
- Lewis acidity (1)
- Lithium niobate (1)
- Meisenheimer complex (1)
- N ligands (1)
- NMR spectroscopy (1)
- Optical Activity (1)
- PAH formation (1)
- Phosphor (1)
- Photochemistry (1)
- Photoelektronenspektroskopie (1)
- Porphyrin arrays (1)
- Pulse shaping (1)
- Raman-scattering (1)
- Reduktionen (1)
- Scanning microscopy (1)
- Schroedinger equation (1)
- Spektroskopie (1)
- Subwavelength structures (1)
- T cells (1)
- UV/Vis spectroscopy (1)
- Ultrafast measurements (1)
- Ultrafast spectroscopy (1)
- Umlagerungen (1)
- Upconversion (1)
- acenes (1)
- acid-sensitive (1)
- amino-acids (1)
- ammonia borane (1)
- amphiphilic systems (1)
- antiaromaticity (1)
- aromaticity (1)
- atomic physics (1)
- beryllium (1)
- bismuth (1)
- bond Activation (1)
- bond theory (1)
- bonding (1)
- boron tetraiodide (1)
- cameras (1)
- carbenes (1)
- carbon monoxide (1)
- carbon nanotubes and fullerenes (1)
- catalysis (1)
- cationic species (1)
- cell differentiation (1)
- charge-coupled device (1)
- chemical bonding (1)
- cholera (1)
- circularly-polarized light (1)
- coherent multidimensional spectroscopy (1)
- coherent spectroscopy (1)
- computational chemistry (1)
- computational physics (1)
- covalent reversible inhibition (1)
- covariance and correlation (1)
- cysteine protease (1)
- cytokines (1)
- density functional theory (1)
- diborenes (1)
- dichroism (1)
- diradicals (1)
- dissociative photoionisation (1)
- dye chemistry (1)
- electric field distribution (1)
- electrophilic (het)arene (1)
- electrophilic substitution (1)
- excimer formation (1)
- exciton dynamics (1)
- exciton transfer (1)
- exciton-exciton (1)
- excitons (1)
- femtochemistry (1)
- fluorescence (1)
- fluorescence spectra (1)
- free electron laser (1)
- free jet (1)
- gas phase (1)
- gold nanoparticles (1)
- ground states (1)
- halides (1)
- high energy (1)
- high-temperature chemistry (1)
- higher lying electronic states (1)
- homochirality (1)
- hydration dynamics (1)
- hydrogen bonding (1)
- hydrogen storage (1)
- hydrolysis (1)
- immune evasion (1)
- in vitro study (1)
- information theory entropy (1)
- infrared spectroscopy (1)
- infrared-spectra (1)
- ionization energy (1)
- ionization potential (1)
- kinetics (1)
- laser (1)
- laser spectroscopy (1)
- length scale (1)
- main group elements (1)
- manganese (1)
- metal cluster (1)
- metal-cluster hybrid systems (1)
- metal-metal interactions (1)
- methyl exchange (1)
- methylbismuth (1)
- modulators (1)
- molecular dynamics (1)
- molecular mechanics (1)
- molecular orbitals (1)
- molecular physics (1)
- molecular switch (1)
- nanocavities (1)
- nanophotonics and plasmonics (1)
- nanowire formation (1)
- naphthyridine (1)
- natural products (1)
- nitrogen trichloride (1)
- nodal structures (1)
- nonadiabatic dynamics (1)
- noncovalent interactions (1)
- nucleophilic addition (1)
- nucleophilic aromatic substitution (1)
- optical response (1)
- optical spectroscopy (1)
- optics (1)
- organic electronics (1)
- organometallic chemistry (1)
- oxidation (1)
- oxidative addition (1)
- p-block element (1)
- particle correlations (1)
- particles (1)
- peptidomimetic sequence (1)
- phosphorus heterocycles (1)
- photonic devices (1)
- pincer ligand (1)
- platinum (1)
- polymers (1)
- potassium reagent (1)
- protease (1)
- protease inhibitors (1)
- protein hydration (1)
- pyrene dimer (1)
- quantum chemistry (1)
- quantum mechanics (1)
- quantum optics (1)
- quantum wave functions (1)
- radical reactions (1)
- reaction mechanisms (1)
- reactivity and selectivity study (1)
- regulatory T cells (1)
- s-block metals (1)
- small interfering RNAs (1)
- solar fuels (1)
- solid-state sturcture (1)
- solvent effects (1)
- solvent-dependent fluorescence yield (1)
- solvents (1)
- strong coupling (1)
- structural biology (1)
- superstructure (1)
- supramolecular folding (1)
- supramolecular materials (1)
- synchrotron radiatoren (1)
- tetracene dimer (1)
- threshold photoelectron spectroscopy (1)
- time resolved spectroscopy (1)
- time-dependent Schrodinger equation (1)
- time-resolved photoelectron spectroscopy (1)
- total electric field (1)
- toxins (1)
- trans-formanilide (1)
- transient absorption (1)
- transition charge (1)
- transition density (1)
- transition dipole moment (1)
- transition metal dichalcogenide (1)
- ultrafast measurements (1)
- ultrafast spectroscopy (1)
- ultrashort time (1)
- ultraviolet light (1)
- warhead (1)
- water migration (1)
- water oxidation (1)
- wave functions (1)
- xylylene (1)
- π-complex (1)
- π-conjugated systems (1)
Institute
- Institut für Physikalische und Theoretische Chemie (68) (remove)
Sonstige beteiligte Institutionen
- Arizona State University, Tempe, Arizona, USA (1)
- Department of Chemistry, Sungkyunkwan University, 440-746 Suwon, Republic of Korea (1)
- Fachbereich Physik, Universität Konstanz, D-78464 Konstanz, Germany (1)
- Fraunhofer-Institute for Applied Optics and Precision Engineering IOF Jena, Germany (1)
- Friedrich Schiller University Jena, Germany (1)
- Institut für Optik und Atomare Physik, Technische Universität Berlin, 10623 Berlin, Germany (1)
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan (1)
- Max Planck School of Photonics Jena, Germany (1)
- National Institute for Materials Science, Tsukuba, Japan (1)
- Paul Scherrer Institut (1)
The development of ligands capable of effectively stabilizing highly reactive main‐group species has led to the experimental realization of a variety of systems with fascinating properties. In this work, we computationally investigate the electronic, structural, energetic, and bonding features of proximity‐enforced group 13–15 homodimers stabilized by a rigid expanded pincer ligand based on the 1,8‐naphthyridine (napy) core. We show that the redox‐active naphthyridine diimine (NDI) ligand enables a wide variety of structural motifs and element‐element interaction modes, the latter ranging from isolated, element‐centered lone pairs (e.g., E = Si, Ge) to cases where through‐space π bonds (E = Pb), element‐element multiple bonds (E = P, As) and biradical ground states (E = N) are observed. Our results hint at the feasibility of NDI‐E2 species as viable synthetic targets, highlighting the versatility and potential applications of napy‐based ligands in main‐group chemistry.
Isolated 2‐phenylallyl radicals (2‐PA), generated by pyrolysis from a nitrite precursor, have been investigated by IR/UV ion dip spectroscopy using free electron laser radiation. 2‐PA is a resonance‐stabilized radical that is considered to be involved in the formation of polycyclic aromatic hydrocarbons (PAH) in combustion, but also in interstellar space. The radical is identified based on its gas‐phase IR spectrum. Furthermore, a number of bimolecular reaction products are identified, showing that the self‐reaction as well as reactions with unimolecular decomposition products of 2‐PA form several PAH efficiently. Possible mechanisms are discussed and the chemistry of 2‐PA is compared with the one of the related 2‐methylallyl and phenylpropargyl radicals.
Covalent peptidomimetic protease inhibitors have gained a lot of attention in drug development in recent years. They are designed to covalently bind the catalytically active amino acids through electrophilic groups called warheads. Covalent inhibition has an advantage in terms of pharmacodynamic properties but can also bear toxicity risks due to non-selective off-target protein binding. Therefore, the right combination of a reactive warhead with a well-suited peptidomimetic sequence is of great importance. Herein, the selectivities of well-known warheads combined with peptidomimetic sequences suited for five different proteases were investigated, highlighting the impact of both structure parts (warhead and peptidomimetic sequence) for affinity and selectivity. Molecular docking gave insights into the predicted binding modes of the inhibitors inside the binding pockets of the different enzymes. Moreover, the warheads were investigated by NMR and LC-MS reactivity assays against serine/threonine and cysteine nucleophile models, as well as by quantum mechanics simulations.
We study the influence of nodal structures in two-dimensional quantum mechanical densities on wave packet entanglement. This is motivated by our recent study [Entropy, 25, 970 (2023)], which showed that the mutual information derived from the momentum-space probability density of a coupled two-particle system exhibits an unusual time dependence, which is not encountered if the position-space density is employed in the calculation. In studying a model density, here, we identify cases where the mutual information increases with the number of nodes in the wave function and approaches a finite value, whereas in this limit, the linear correlation vanishes. The results of the analytical model are then applied to interpret the correlation measures for coupled electron-nuclear dynamics, which are treated by numerically solving the time-dependent Schrödinger equation.
We have investigated the photoionization of ammonia borane (AB) and determined adiabatic ionization energy to be 9.26±0.03 eV for the X\(^{+}\) \(^{2}\)E←X \(^{1}\)A\(_{1}\) transition. Although the threshold photoelectron spectrum appears at first glance to be similar to the one of the isosteric ethane, the electronic situation differs markedly, due to different orbital energies. In addition, an appearance energy AE\(_{0K}\)-(NH\(_{3}\)BH\(_{3}\), NH\(_{3}\)BH\(_{2}\)\(^{+}\))= 10.00±0.03 eV has been determined, corresponding to the loss of a hydrogen atom at the BH\(_{3}\)-site. From the data, a 0 K bond dissociation energy for the B−H bond in the cation of 71.5±3 kJ mol\(^{-1}\) was derived, whereas the one in the neutral compound has been estimated to be 419±10 kJ mol\(^{-1}\).
Excitons in atomically thin transition-metal dichalcogenides (TMDs) have been established as an attractive platform to explore polaritonic physics, owing to their enormous binding energies and giant oscillator strength. Basic spectral features of exciton polaritons in TMD microcavities, thus far, were conventionally explained via two-coupled-oscillator models. This ignores, however, the impact of phonons on the polariton energy structure. Here we establish and quantify the threefold coupling between excitons, cavity photons, and phonons. For this purpose, we employ energy-momentum-resolved photoluminescence and spatially resolved coherent two-dimensional spectroscopy to investigate the spectral properties of a high-quality-factor microcavity with an embedded WSe\(_2\) van-der-Waals heterostructure at room temperature. Our approach reveals a rich multi-branch structure which thus far has not been captured in previous experiments. Simulation of the data reveals hybridized exciton-photon-phonon states, providing new physical insight into the exciton polariton system based on layered TMDs.
The understanding of excimer formation and its interplay with the singlet-correlated triplet pair state \(^{1}\)(TT) is of high significance for the development of efficient organic electronics. Here, we study the photoinduced dynamics of the tetracene dimer in the gas phase by time-resolved photoionisation and photoion imaging experiments as well as nonadiabatic dynamics simulations in order to obtain mechanistic insight into the excimer formation dynamics. The experiments are performed using a picosecond laser system for excitation into the S\(_{2}\) state and reveal a biexponential time dependence. The time constants, obtained as a function of excess energy, lie in the range between ≈10 ps and 100 ps and are assigned to the relaxation of the excimer on the S\(_{1}\) surface and to its deactivation to the ground state. Simulations of the quantum-classical photodynamics are carried out in the frame of the semi-empirical CISD and TD-lc-DFTB methods. Both theoretical approaches reveal a dominating relaxation pathway that is characterised by the formation of a perfectly stacked excimer. TD-lc-DFTB simulations have also uncovered a second relaxation channel into a less stable dimer conformation in the S\(_{1}\) state. Both methods have consistently shown that the electronic and geometric relaxation to the excimer state is completed in less than 10 ps. The inclusion of doubly excited states in the CISD dynamics and their diabatisation further allowed to observe a transient population of the \(^{1}\)(TT) state, which, however, gets depopulated on a timescale of 8 ps, leading finally to the trapping in the excimer minimum.
We investigate NCl\(_{3}\) and the NCl\(_{2}\) radical by photoelectron-photoion coincidence spectroscopy using synchrotron radiation. The mass selected threshold photoelectron spectrum (ms-TPES) of NCl\(_{3}\) is broad and unstructured due to the large geometry change. An ionization energy of 9.7±0.1 eV is estimated from the spectrum and supported by computations. NCl2 is generated by photolysis at 213 nm from NCl\(_{3}\) and its ms-TPES shows an extended vibrational progression with a 90 meV spacing that is assigned to the symmetric N−Cl stretching mode in the cation. An adiabatic ionization energy of 9.94 ± 0.02 eV is determined.
The development of complexes featuring low-valent, multiply bonded metal centers is an exciting field with several potential applications. In this work, we describe the design principles and extensive computational investigation of new organometallic platforms featuring the elusive manganese-manganese bond stabilized by experimentally realized N-heterocyclic carbenes (NHCs). By using DFT computations benchmarked against multireference calculations, as well as MO- and VB-based bonding analyses, we could disentangle the various electronic and structural effects contributing to the thermodynamic and kinetic stability, as well as the experimental feasibility, of the systems. In particular, we explored the nature of the metal-carbene interaction and the role of the ancillary η\(^{6}\) coordination to the generation of Mn\(_{2}\) systems featuring ultrashort metal-metal bonds, closed-shell singlet multiplicities, and positive adiabatic singlet-triplet gaps. Our analysis identifies two distinct classes of viable synthetic targets, whose electrostructural properties are thoroughly investigated.
The NHC-stabilised diboryne (B\(_2\)(SIDep)\(_2\); SIDep=1,3-bis(2,6-diethylphenyl)imidazolin-2-ylidene) undergoes a high-yielding P−P bond activation with tetraethyldiphosphine at room temperature to form a B\(_2\)P\(_2\) heterocycle via a diphosphoryldiborene by 1,2-diphosphination. The heterocycle can be oxidised to a radical cation and a dication, respectively, depending on the oxidant used and its counterion. Starting from the planar, neutral 1,3-bis(alkylidene)-1,3-diborata-2,4-diphosphoniocyclobutane, each oxidation step leads to decreased B−B distances and loss of planarity by cationisation. X-ray analyses in conjunction with DFT and CASSCF/NEVPT2 calculations reveal closed-shell singlet, butterfly-shaped structures for the NHC-stabilised dicationic B\(_2\)P\(_2\) rings, with their diradicaloid, planar-ring isomers lying close in energy.