A5073872433- Molecular Junctions and Nanostructures
- Surface Chemistry and Catalysis
- Force Microscopy Techniques and Applications
- Graphene research and applications
- Organic Electronics and Photovoltaics
- Spectroscopy and Quantum Chemical Studies
- Surface and Thin Film Phenomena
- Dendrimers and Hyperbranched Polymers
- Supramolecular Self-Assembly in Materials
- Polymer Surface Interaction Studies
- Advanced Polymer Synthesis and Characterization
- Lipid Membrane Structure and Behavior
- Conducting polymers and applications
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Mechanical and Optical Resonators
- 2D Materials and Applications
- Quantum Dots Synthesis And Properties
- Electrochemical Analysis and Applications
- Advanced Chemical Physics Studies
- Luminescence and Fluorescent Materials
- Advanced biosensing and bioanalysis techniques
- Surfactants and Colloidal Systems
- Liquid Crystal Research Advancements
- Fullerene Chemistry and Applications
Humboldt-Universität zu Berlin
2016-2025
Robert Bosch (Germany)
2023
Cluster of Excellence "Matters of Activity. Image Space Material"
2021
Ministerium für Heimat, Kommunales, Bau und Gleichstellung des Landes Nordrhein-Westfalen
2018
Ambulatory Rehabilitation Center Berlin Adlershof
2015-2016
Freie Universität Berlin
1998-2015
Chiba University
2014
Soochow University
2014
Shandong University
2014
Federal Institute For Materials Research and Testing
2011
Two-dimensional molecular patterns were obtained by the adsorption of long-chain alkanes, alcohols, fatty acids, and a dialkylbenzene from organic solutions onto basal plane graphite. In situ scanning tunneling microscopy (STM) studies revealed that these molecules organize in lamellae with extended alkyl chains oriented parallel to lattice axis within The planes carbon skeletons, however, can be either predominantly perpendicular or substrate surface, causing lamellar near registry (alkanes...
Dendrimers are presently one of the most intensely studied classes compounds because their unusual structure. They can be described as a jungle entangled branches traversed by winding trails which lead to sweet fruits and bright blossoms. On these reach thicket's interior well find way out. Expressed less lyrically, this thicket stands for regularly branched, densely packed structures, represent voids channels not filled bent back but solvent. The fruit blossoms photochemically,...
Abstract The optical, structural, and electrical properties of thin layers made from poly(3‐hexylthiophene) (P3HT) samples different molecular weights are presented. As reported in a previous paper by Kline et al., Adv. Mater. 2003 , 15 1519, the mobilities these strong function weight, with largest mobility found for weight. Atomic force microscopy studies reveal complex polycrystalline morphology which changes considerably upon annealing. X‐ray show occurrence layered phase all P3HT...
Abstract α‐Methylene‐γ‐butyrolactones [dihydro‐3‐methylene‐2(3 H )furanones] constitute an important group of natural products and possess wide‐ranging biological activities. Progress in the synthesis heterocycle classification synthetic methods are not only practical interest, but also fundamentally as a current example for construction unusual 1,4‐functionality distance α‐substituted acrylic ester moiety which is susceptible to nucleophilic attack.
Graphitic carbon nitride has been predicted to be structurally analogous carbon-only graphite, yet with an inherent bandgap. We have grown, for the first time, macroscopically large crystalline thin films of triazine-based, graphitic (TGCN) using ionothermal, interfacial reaction starting abundant monomer dicyandiamide. The consist stacked, two-dimensional (2D) crystals between a few and several hundreds atomic layers in thickness. Scanning force transmission electron microscopy show...
Nonequilibrium carrier dynamics in single exfoliated graphene layers on muscovite substrates are studied by ultrafast optical pump-probe spectroscopy and compared with microscopic theory. The very high 10-fs-time resolution allows for mapping the equilibration into a quasi-Fermi distribution subsequent slower relaxation stages. Coulomb-mediated carrier-carrier carrier-optical phonon scattering essential forming hot separate Fermi distributions of electrons holes which cool intraband...
Packing Bananas and Boomerangs Assembling achiral molecules typically generates domains. However, odd things can happen when the are banana-or boomerang-shaped—their cores twist out of plain to form left- or right-handed helices, which then pack into chiral domains that will polarize light (see Perspective by Amabilino ). Hough et al. (p. 452 ) show if you make situation even more complex frustrating packing adjacent layers, create a material appears be macroscopically isotropic with only...
The electronic properties of molecules can in some cases be elucidated by scanning tunneling microscopy and spectroscopy. current–voltage characteristics through the aromatic core a benzocoronene molecule (1), localized with submolecular resolution, are same those diode, caused single contact two electrodes. R = n-C12H25.
The energy-level alignment at interfaces between three electroactive conjugated organic materials and Au was systematically varied by adjusting the precoverage of metal substrate with electron acceptor tetrafluoro-tetracyanoquinodimethane (F4-TCNQ). Photoelectron spectroscopy revealed that transfer from to adsorbed F4-TCNQ responsible for lowering hole-injection barrier as much 1.2 eV. This novel interface modification scheme is independent charge complex formation ability acceptor.
Single-molecule electronics, that is, realizing novel electronic functionalities from single (or very few) molecules, holds promise for application in various technologies, including signal processing and sensing. Nanographenes, which are extended polycyclic aromatic hydrocarbons (PAHs), highly attractive subjects studies of single-molecule electronics because the properties their flat conjugated systems can be varied dramatically through synthetic modification sizes topologies. Single...
Sixteen thiophene units make up the longest oligothiophene to date, 64 Å-long oligomer 4. Like its shorter homologues 1–3, 4 forms molecular structures on surfaces, which can be examined by scanning tunneling microscopy with submolecular resolution. Oligomers 1-4 considered components of "molecular wires" and serve as model compounds for study charge transport in electrically conducting polymers.
Monolayers of hexa-alkyl substituted derivatives hexa-peri-hexabenzocoronene (HBC) 1b have previously been investigated by scanning tunneling microscopy (STM) and spectroscopy (STS). It is expected that different functional groups (electron donating or withdrawing) connected to the aromatic core will influence packing pattern possibly current-voltage characteristics as well. In order provide suitable model systems, a new synthetic approach synthesize functionalized HBC has developed. This...
Scanning tunneling microscopy (STM) studies at the interface between basal plane of graphite and organic solutions or melts long chain alkanes alkyl derivatives reveal that molecules order in lamellae with main molecular axes oriented parallel to substrate. Here we employ dynamics (MD) simulations obtain more details on within alkane as a function density. We find orientation carbon zigzag planes relative is governed by subtle interplay packing entropic effects. In addition, consider...
A molecular monolayer adsorbed at the interface between basal plane of graphite and an organic solution didodecylbenzene has been observed in situ by scanning tunneling microscopy a resolution 0.2 nm. The forms 2D polycrystal with crystallite sizes range few nanometers. predominant domain boundary is described glide plane. Fast image recording allowed, for first time, direct observation dynamics on time scale 100 ms. In particular, motion boundaries could be associated diffusing ``free volume.''
Abstract Controlling contact resistance in organic field‐effect transistors (OFETs) is one of the major hurdles to achieve transistor scaling and dimensional reduction. In particular context ambipolar and/or light‐emitting OFETs it a difficult challenge obtain efficient injection both electrons holes from injecting electrode such as gold since semiconductors have intrinsically large band gaps resulting significant barrier heights for at least type carrier. Here, systematic control electron...
Evidence for temperature-dependent electron band dispersion in a pentacene thin film polymorph on graphite is provided by angle- and energy-dependent ultraviolet photoelectron spectroscopy. The bands derived from the highest occupied molecular orbital exhibit of approximately 190 meV at room temperature, 240 120 K. Intermolecular electronic coupling films thus confirmed to be dependent temperature possibly crystal structure, as suggested additional infrared absorption measurements.
Candidates for molecular nanowires the interconnection of gold nanoelectrodes in a molecular-scale electronic device are to be found end-functionalised poly(para-phenyleneethynylene)s. The self-assembly these polymers was studied on atomically flat solid substrates. On graphite, sub-molecularly resolved imaging with scanning tunneling microscopy revealed nanorods 2 D nematic-like texture, while mica, force (see picture) shows that can self-assemble into highly oriented micrometer-long...
Carbon K-shell NEXAFS (near edge x-ray absorption fine structure) spectra of oriented hydrocarbon chains in Langmuir–Blodgett (LB) monolayers were measured and used to study the orientation these molecules. The LB assembled from arachidic acid or cadmium calcium arachidate on oxidized Si(111) surface. observed resonances are assigned transitions excited states which localized individual CH2 groups C–C bonds. From a detailed analysis using curve-fitting techniques angular dependence various...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDABCO-catalyzed coupling of aldehydes with activated double bonds. 4. Stereoselective synthesis trisubstituted olefins and terpenoid building blocks via 2-(hydroxyalkyl)-2-propenoic estersHans Martin R. Hoffmann Juergen RabeCite this: J. Org. Chem. 1985, 50, 20, 3849–3859Publication Date (Print):October 1, 1985Publication History Published online1 May 2002Published inissue 1 October...
The solubilization behavior of nile red dye in aqueous surfactant and micellar solutions was studied by optical spectroscopic techniques, dynamic light scattering, atomic force microscopy. Nile exhibits considerable absorption the submicellar concentration region. When dispersed and/or solution, molecules tend to form nonemissive dimers H-type aggregates through π-π stacking interactions. This phenomenon may limit use studies. In presence ionic SDS CTAB micelles, appears take place primarily...