Refine
Has Fulltext
- no (173) (remove)
Year of publication
- 2015 (173) (remove)
Document Type
- Article (152)
- Doctoral Thesis (11)
- Review (3)
- Conference Proceeding (2)
- Preprint (2)
- Monograph/Edited Volume (1)
- Habilitation Thesis (1)
- Other (1)
Is part of the Bibliography
- yes (173)
Keywords
- biomaterials (4)
- Arenes (3)
- Cross-coupling (3)
- Palladium (3)
- click chemistry (3)
- peptides (3)
- polymers (3)
- self-assembly (3)
- Anisotropy effect (2)
- FRET (2)
- H-1 NMR (2)
- Ring current effect (2)
- Theoretical calculations (2)
- block copolymers (2)
- dendrimers (2)
- density functional calculations (2)
- fluorescence (2)
- hydrogen bonds (2)
- molecular rods (2)
- 1,2-Dithiosquarate,1,2-Dithiosquaratonickelate (1)
- 1,3-Oxasilinanes (1)
- 2,2-Disubstituted adamantane derivatives (1)
- 2-Hydroxyethylammonium 1-R-indol-3-ylsulfanylacetates (1)
- 2-Substituted adamantane derivatives (1)
- 3-Silatetrahydropyrans (1)
- AFM (1)
- ATR-FTIR (1)
- Allylic compounds (1)
- Amides (1)
- Anisotropy (1)
- Annulation (1)
- Antiplasmodial activity (1)
- Aptamer (1)
- Assignment of stereochemistry (1)
- Azadironolide (1)
- Azobenzene (1)
- B3LYP/6-31+G(d,p) calculations (1)
- Barrier to ring inversion (1)
- Beer mashing (1)
- Bentonite clay (1)
- Benzenoid structure (1)
- Biaryls (1)
- Biomaterials (1)
- Biomineralization (1)
- Bone repair material (1)
- Breakthrough curve (1)
- Brewster angle microscopy (1)
- C-13 NMR (1)
- C-C coupling (1)
- Cadmium (1)
- Calcium phosphates (1)
- Carbene ligands (1)
- Carbohydrate mimics (1)
- Carbohydrates (1)
- Catalytic reaction (1)
- Cationic surfactants (1)
- Cavity ring-down spectroscopy (1)
- Chiral dopants (1)
- Classical MD (1)
- Click chemistry (1)
- Cobalt (1)
- Composite hydrogels (1)
- Confocal microscopy (1)
- Conformational analysis (1)
- Conformational equilibrium (1)
- Coordination polymers (1)
- Crystal and molecular structure (1)
- Crystal structures (1)
- Cytotoxicity (1)
- DNA copolymers (1)
- DNA nanotechnology (1)
- DOPA (1)
- Delta-Kohn Sham method (1)
- EPR spectroscopy (1)
- ESI (1)
- Electrospinning (1)
- Ellipsometry (1)
- Energy (1)
- Energy-transfer probe (1)
- Enzymatic milk coagulation (1)
- Exciplex (1)
- F12 methods (1)
- Flexible linker (1)
- Fluorescence (1)
- Fluorescence imaging (1)
- Fluorescence spectroscopy (1)
- Fluorescent probes (1)
- Fluoroassay (1)
- Fourier-transform infrared (1)
- G-quadruplexes (1)
- GIAO calculations (1)
- Gas sorption (1)
- Gas-phase electron diffraction (1)
- Gate-effects (1)
- Gold (1)
- HPLC (1)
- Health (1)
- Heavy metal ions (1)
- Heterocycles (1)
- Heterogeneous catalysis (1)
- Human donor blood (1)
- Hybrid materials (1)
- Hydrogel (1)
- Hydrogen-bonding (1)
- Hydrophobic (1)
- ICSS (1)
- IMS (1)
- Imidazole (1)
- Immunoactive properties (1)
- Interchain interactions (1)
- Ionic liquids (1)
- Ionogels (1)
- Kinetic model (1)
- L-selectin (1)
- LCST behavior (1)
- Langmuir monolayer (1)
- Lanthanide (1)
- Layer-by-layer (1)
- Light scattering (1)
- Limonoid (1)
- Lobelia tupa (1)
- Low temperature NMR spectroscopy (1)
- Luminescence spectroscopy (1)
- Michael addition (1)
- Microwave chemistry (1)
- Molecular dynamics simulations (1)
- Molecular orientation (1)
- N (1)
- NCA (1)
- NICE-2014 (1)
- Nanoparticles (1)
- Natural products (1)
- Nickel oxide (1)
- Oxygen heterocycles (1)
- P ligands (1)
- Pentylsedinine (1)
- Phenols (1)
- Photoinduced optical anisotropy (1)
- Photon Density Wave spectroscopy (1)
- Pi interactions (1)
- Piperidine alkaloid (1)
- Platinum group metals (1)
- Poly vinyl alcohol (1)
- Polyaromatic fragments (1)
- Polyether ether ketone (1)
- Polyethyleneimine (1)
- Polyimides (1)
- Polypeptoid (1)
- Post-polymerization modification (1)
- Process analytical technology (1)
- Protic 2-hydroxyethylammonium ionic liquids (1)
- Quantum chemical calculations (1)
- Quasi-aromaticity (1)
- Quinonoid structure (1)
- Rearrangement (1)
- SANS (1)
- SAXS (1)
- Sensors (1)
- Simulation of polymer XPS (1)
- Solid-phase extraction (1)
- Solvent effects (1)
- Solvothermal synthesis (1)
- Substituent chemical shifts (1)
- Sulphoxide (1)
- Supramolecular ball structure (1)
- Supramolecular chemistry (1)
- Surface enhanced Raman scattering (SERS) (1)
- Surface relief grating (1)
- Surfactant micelles (1)
- Synthetic methods (1)
- TG/DTA (1)
- TSNMRS (1)
- Thermal broadening effects (1)
- Thermoresponsive (1)
- Thiol-ene (1)
- ToF-SIMS (1)
- Toonacilin (1)
- Toonapubesins F (1)
- Total synthesis (1)
- Turraea nilotica (1)
- Turraea robusta (1)
- X-ray structure (1)
- XPS (1)
- ab initio (1)
- ab initio calculations (1)
- aldol reaction (1)
- alignments (1)
- amino acid N-carboxyanhydride (NCA) (1)
- amorphous polymers (1)
- anti-HIV (1)
- articulated rods (1)
- basis sets (1)
- benzofurans (1)
- biocompatibility (1)
- biodegradable polymers (1)
- biorecognition reactions (1)
- body temperature (1)
- broad melting temperature range (1)
- carbohydrates (1)
- catanionic surfactants (1)
- cell culture device (1)
- cell-material interaction (1)
- coating (1)
- collagen (1)
- column operation mode (1)
- conformational analysis (1)
- controlled release (1)
- copolymer networks (1)
- coupled-cluster (1)
- crystal structure (1)
- cyclic voltammetry (1)
- cycloaddition (1)
- degradable polyester (1)
- dendritic cells (1)
- di(ethylene glycol) methy ether methacrylate (1)
- dielectric spectroscopy (1)
- dispersion (1)
- electric fields (1)
- electrodes (1)
- electrostatic interactions (1)
- enzyme inhibitors (1)
- ephedrine/pseudoephedrine (1)
- fibers (1)
- fluorescent probes (1)
- galactosylceramide (1)
- gas sensing (1)
- gels (1)
- glycal (1)
- glycolipids (1)
- gold (1)
- hollow-core photonic bandgap fiber (1)
- hydrogels (1)
- hydrogen bonding (1)
- hydrogen-2 (1)
- hydrophilic-to-lipophilic balance (1)
- interfaces (1)
- intermolecular interactions (1)
- inverse micelles (1)
- isotope ecology (1)
- ketones (1)
- leaf wax (1)
- lipase release (1)
- liposomes (1)
- mAb (1)
- magnetic nanoparticles (1)
- maleimide (1)
- membranes (1)
- mesenchymal stem cells (1)
- metal coordination (1)
- metal-free crosslinking (1)
- microgels (1)
- microparticles (1)
- mixed quantum-classical methodology (1)
- molecular structure (1)
- multiblock copolymer (1)
- mussel byssus (1)
- n-alkanes (1)
- nAChR (1)
- nanocomposites (1)
- nanoparticle characterization (1)
- nanoparticles (1)
- nanoreactor (1)
- nanostructures (1)
- neuroleptics (1)
- nucleation polymerization (1)
- oak tree (1)
- oligo(ethylene glycol) methyl ether methacrylate (1)
- oligospiroketals (1)
- one-pot reaction (1)
- optical spectra (1)
- orientational memory (1)
- osteogenic differentiation (1)
- oxygen (1)
- oxygen heterocycles (1)
- oxygenation (1)
- palmitic acid (1)
- palmitoylation (1)
- para-Nitro-pyridine N-oxides (1)
- peroxides (1)
- pesticides (1)
- phosphate (1)
- photodynamic therapy (1)
- photonic crystals (1)
- photopolymerization (1)
- platinum (1)
- poly[(rac-lactide)-co-glycolide] (1)
- polydepsipeptide (1)
- polyesterurethanes (1)
- polymersomes (1)
- polypeptoid (1)
- polysaccharides (1)
- polystyrene-block-poly(4-vinylpyridine) (1)
- porphyrins (1)
- potassium (1)
- processing (1)
- programmable adhesion (1)
- propargyl (1)
- properties (1)
- protein-protein interactions (1)
- pyrene excimer (1)
- radical addition (1)
- rearrangement (1)
- reorientation (1)
- responsive materials (1)
- responsive polymers (1)
- reversible bidirectional shape-memory polymer (1)
- ring opening polymerization (1)
- ring-opening polymerization (1)
- selective syntheses (1)
- sensors (1)
- shape-memory effect (1)
- shape-memory polymer (1)
- silica nanoparticles (1)
- singlet oxygen (1)
- soft-templating (1)
- solid-phase extraction (1)
- solid-state NMR (1)
- solvent vapor annealing (1)
- spectroscopic ellipsometry (1)
- spray imaging (1)
- stimuli-sensitive polymers (1)
- sugar amino acids (1)
- supramolecular chemistry (1)
- surface functionalization (1)
- surface-initiated photopolymerization (1)
- surfactants (1)
- synthesis (1)
- tetrapyrroles (1)
- thermoresponsive (1)
- thermoresponsive polymers (1)
- thermoresponsive substrates (1)
- thiol (1)
- tin-rich ITO (1)
- two-photon (1)
- two-photon absorption (1)
- ultrasound (1)
- vesicles (1)
- water/decane contact angle (1)
- yolk@shell materials (1)
Institute
- Institut für Chemie (173) (remove)
A concentrated solution of a symmetric triblock copolymer with a thermoresponsive poly(methoxy diethylene glycol acrylate) (PMDEGA) middle block and short hydrophobic, fully deuterated polystyrene end blocks is investigated in D2O where it undergoes a lower critical solution temperature-type phase transition at ca. 36 A degrees C. Small-angle neutron scattering (SANS) in a wide temperature range (15-50 A degrees C) is used to characterize the size and inner structure of the micelles as well as the correlation between the micelles and the formation of aggregates by the micelles above the cloud point (CP). A model featuring spherical core-shell micelles, which are correlated by a hard-sphere potential or a sticky hard-sphere potential together with a Guinier form factor describing aggregates formed by the micelles above the CP, fits the SANS curves well in the entire temperature range. The thickness of the thermoresponsive micellar PMDEGA shell as well as the hard-sphere radius increase slightly already below the cloud point. Whereas the thickness of the thermoresponsive micellar shell hardly shrinks when heating through the CP and up to 50 A degrees C, the hard-sphere radius decreases within 3.5 K at the CP. The volume fraction decreases already significantly below the CP, which may be at the origin of the previously observed gel-sol transition far below the CP (Miasnikova et al., Langmuir 28: 4479-4490, 2012). Above the CP, small, and at higher temperatures, large aggregates are formed by the micelles.
A simple and straightforward approach to new polymetallic Ag-I and Cu-I supramolecules is presented. The reaction of N,P,N,P,N ligand 2 with Ag-I ions affords a trimetallic complex bearing a triangular Ag-3 core; metallophilic interactions are stabilized by ligands that display a multiple bridging coordination mode as 10-electron donors. Heteroleptic polymetallic Ag-I and Cu-I complexes based on ligand 2 and the 1,12-diazaperylene (dape) ligand are obtained by an alternative molecular organization of the polymetallic arrays compared to that in homoleptic complexes of ligand 2.
The PEPPSI (Pyridine Enhanced Precatalyst Preparation, Stabilization and Initiation) complexes 12-15 with the structure [PdCl2{(CN)(2)IMes}(3-R-py)] (12: R = H; 13: R = Cl; 14: R = Br; 15: R = CN) bearing the maleonitrile-based N-heterocyclic carbene (NHC) (CN)(2)IMes ({(CN)(2)IMes}: 4,5-dicyano-1,3-dimesitylimidazol-2-ylidene) were prepared. Solid state structures of 14 and 15 were obtained. Complexes 14 and 15 adopt a slightly distorted square-planar coordination geometry in the solid state with the substituted pyridine ligand trans to the NHC. Catalytic activities of precatalysts 12-15 were studied and subsequently compared to complexes [PdCl2{(CN)(2)IMes}(PPh3)] (4) and [PdCl(dmba){(CN)(2)IMes}] (5) recently reported by our group in the Suzuki-Miyaura reaction of various aryl halides and phenylboronic acid. Reactions using previously reported [PdCl2(IMes)(py)] (IMes: 1,3-dimesitylimidazol-2-ylidene) (1) were also carried out and their results contrasted to those involving 12-15, 4 and 5. Differences in initiation rates and the catalytically active species related to the seven complexes in regards to the throw away ligand were investigated. Poisoning experiments with mercury show that palladium nanoparticles are responsible for the catalytic activity.
Optical properties of modified diamondoids have been studied theoretically using vibrationally resolved electronic absorption, emission and resonance Raman spectra. A time-dependent correlation function approach has been used for electronic two-state models, comprising a ground state (g) and a bright, excited state (e), the latter determined from linear-response, time-dependent density functional theory (TD-DFT). The harmonic and Condon approximations were adopted. In most cases origin shifts, frequency alteration and Duschinsky rotation in excited states were considered. For other cases where no excited state geometry optimization and normal mode analysis were possible or desired, a short-time approximation was used. The optical properties and spectra have been computed for (i) a set of recently synthesized sp(2)/sp(3) hybrid species with CQC double-bond connected saturated diamondoid subunits, (ii) functionalized (mostly by thiol or thione groups) diamondoids and (iii) urotropine and other C-substituted diamondoids. The ultimate goal is to tailor optical and electronic features of diamondoids by electronic blending, functionalization and substitution, based on a molecular-level understanding of the ongoing photophysics.
Optical properties of modified diamondoids have been studied theoretically using vibrationally resolved electronic absorption, emission and resonance Raman spectra. A time-dependent correlation function approach has been used for electronic two-state models, comprising a ground state (g) and a bright, excited state (e), the latter determined from linear-response, time-dependent density functional theory (TD-DFT). The harmonic and Condon approximations were adopted. In most cases origin shifts, frequency alteration and Duschinsky rotation in excited states were considered. For other cases where no excited state geometry optimization and normal mode analysis were possible or desired, a short-time approximation was used. The optical properties and spectra have been computed for (i) a set of recently synthesized sp2/sp3 hybrid species with C[double bond, length as m-dash]C double-bond connected saturated diamondoid subunits, (ii) functionalized (mostly by thiol or thione groups) diamondoids and (iii) urotropine and other C-substituted diamondoids. The ultimate goal is to tailor optical and electronic features of diamondoids by electronic blending, functionalization and substitution, based on a molecular-level understanding of the ongoing photophysics.
Double cyclization of short linear peptides obtained by solid phase peptide synthesis was used to prepare bridged bicyclic peptides (BBPs) corresponding to the topology of bridged bicyclic alkanes such as norbornane. Diastereomeric norbornapeptides were investigated by 1H-NMR, X-ray crystallography and CD spectroscopy and found to represent rigid globular scaffolds stabilized by intramolecular backbone hydrogen bonds with scaffold geometries determined by the chirality of amino acid residues and sharing structural features of β-turns and α-helices. Proteome profiling by capture compound mass spectrometry (CCMS) led to the discovery of the norbornapeptide 27c binding selectively to calmodulin as an example of a BBP protein binder. This and other BBPs showed high stability towards proteolytic degradation in serum.
Chiral dopants were obtained by acylation of enantiomerically pure ephedrine and pseudoephedrine with promesogenic carbonyl reagents. The products have been investigated with respect to their chiral transfer ability on nematic host matrices characterized by extreme differences of the dielectric anisotropy. It has been found that the medium dependence of the helicity induction nearly disappears at reduced temperatures. Based on variable temperature H-1 NMR studies on monoacylated homologues, the estimated coalescence temperatures and free activation enthalpies for the hindered rotation around C-N bonds could be correlated with the helical twisting power. Measurements by dielectric spectroscopy reveal the correlation between the molar mass of substituents linked to the chiral building block and the dynamic glass transition of corresponding chiral dopants. Furthermore, the effect of intramolecular and intermolecular hydrogen bonds has been studied by ATR-FTIR spectroscopy.
In this work, we report three isostructural 3D frameworks, named IFP-11 (R = Cl), IFP-12 (R = Br), and IFP-13 (R = Et) (IFP = Imidazolate Framework Potsdam) based on a cobalt(II) center and the chelating linker 2-substituted imidazolate-4-amide-5-imidate. These chelating ligands were generated in situ by partial hydrolysis of 2-substituted 4,5-dicyanoimidazoles under microwave (MW)-assisted conditions in DMF. Structure determination of these IFPs was investigated by IR spectroscopy and a combination of powder X-ray diffraction (PXRD) with structure modeling. The structural models were initially built up from the single-crystal X-ray structure determination of IFP-5 (a cobalt center and 2-methylimidazolate-4-amide-5-imidate linker based framework) and were optimized by using density functional theory calculations. Substitution on position 2 of the linker (R = Cl, Br, and Et) in the isostructural IFP-11, -12, and -13 allowed variation of the potential pore window in 1D hexagonal channels (3.8 to 1.7 angstrom A). The potential of the materials to undergo specific interactions with CO2 was measured by the isosteric heat adsorption. Further, we resynthesized zinc based IFPs, namely IFP-1 = Me), IFP-2 (R = Cl), IFP-3 (R = Br), and IFP-4 (R = Et), and cobalt based IFP-5 under MW-assisted conditions with higher yield. The transition from a nucleation phase to the pure crystalline material of IFP-1 in MW-assisted synthesis depends on reaction time. IFP-1, -3, and -5, which are synthesized by MW-assisted conditions, showed an enhancement of N-2 and CO2, compared to the analogous conventional electrical (CE) heating method based materials due to crystal defects.