Refine
Has Fulltext
- yes (67)
Is part of the Bibliography
- yes (67)
Year of publication
Document Type
- Journal article (67) (remove)
Language
- English (67) (remove)
Keywords
- water oxidation (9)
- self-assembly (7)
- fluorescence (6)
- photocatalysis (6)
- dyes (5)
- polycyclic aromatic hydrocarbons (5)
- dyes/pigments (4)
- perylene bisimide (4)
- aggregation (3)
- aromaticity (3)
- artificial photosynthesis (3)
- catalysis (3)
- energy transfer (3)
- exciton coupling (3)
- homogeneous catalysis (3)
- liquid crystals (3)
- macrocycles (3)
- organic chemistry (3)
- organic photodiodes (3)
- photoinduced electron transfer (3)
- supramolecular chemistry (3)
- J‐aggregates (2)
- Ruthenium complexes (2)
- absorption (2)
- annulation (2)
- azulene (2)
- chirality transfer (2)
- corannulene (2)
- crystal engineering (2)
- cyclophanes (2)
- electrocatalysis (2)
- heterogeneous catalysis (2)
- homogenous catalysis (2)
- hydrocarbons (2)
- ligands (2)
- luminescence (2)
- merocyanines (2)
- nanographene (2)
- organic light emitting diodes (2)
- organic semiconductors (2)
- organic solar cells (2)
- pentacene (2)
- perylene bisimides (2)
- perylene dyes (2)
- phosphorescence (2)
- polymerization (2)
- renewable fuels (2)
- ruthenium (2)
- ruthenium bda complexes (2)
- ruthenium complexes (2)
- solid-state emitters (2)
- spectroscopy (2)
- squaraine dyes (2)
- water (2)
- water splitting (2)
- AIE (1)
- Aromatic-hydrocarbon (1)
- C-C coupling (1)
- Carbon (1)
- Chemie (1)
- Chromophore Assembly (1)
- Corannulene (1)
- Dimers (1)
- Dyes (1)
- Fluorescence (1)
- Functionalization (1)
- Graphene nanoribbons (1)
- J-aggregate behavior (1)
- J-aggregates (1)
- K2–K model (1)
- Liquid-crystalline (1)
- Marcus inverted region (1)
- Merocyanine (1)
- Molecular-dynamics (1)
- Nucleic Acids (1)
- Nucleobase Analogue (1)
- OEG chains (1)
- Organische Chemie (1)
- PBI cyclophane (1)
- PI stacking (1)
- Pathway (1)
- Potential-energy curves (1)
- Simulations (1)
- Sracking (1)
- State (1)
- Supramolecular Element (1)
- Suzuki coupling (1)
- Systems (1)
- \(\alpha\)-phase (1)
- \(\beta\)-phase (1)
- aelf-assembly (1)
- amphiphilic dyes (1)
- amplification (1)
- annihilation (1)
- aqua material (1)
- aqueous medium (1)
- arenes (1)
- aromatic compounds (1)
- association (1)
- boric acid (1)
- boron (1)
- boronate esters (1)
- bulk-heterojunction solar cells (1)
- carbon (1)
- carrier transport (1)
- cascade reactions (1)
- catalyst (1)
- catalyst synthesis (1)
- catalysts (1)
- catalytic (1)
- catalytic activity (1)
- catalytic mechanisms (1)
- charge transport (1)
- charge transport; hydrogen bonding; oligothiophene; organogel; self-assembly (1)
- chirality (1)
- circular polarized luminescence (1)
- cocrystallization (1)
- complexation (1)
- complexity (1)
- conjugated molecule (1)
- cooperative self-assembly (1)
- coordination chemistry (1)
- coordination oligomer (1)
- coordination oligomers (1)
- covalent organic framework (1)
- covalent organic frameworks (1)
- cristal engeneering (1)
- crystalline (1)
- crystals (1)
- curvature (1)
- curved π-systems (1)
- cyclic perylene bisimide (1)
- cyclodehydrogenation (1)
- cylindrical micelles (1)
- deracemization (1)
- diffusion (1)
- diketopyrrolopyrroles (1)
- dimerization (1)
- dinuclear (1)
- dipole-dipole interaction (1)
- donor-acceptor dyad (1)
- donor–acceptor dyads (1)
- duplex structure (1)
- dye assembly (1)
- electrodes (1)
- electronic and spintronic devices (1)
- electronic devices (1)
- electronic structure (1)
- emission (1)
- encapsulation (1)
- enzyme (1)
- excimer (1)
- excimer formation (1)
- films (1)
- flourescence quantum yield (1)
- fluorescent (1)
- folded macrocyles (1)
- folding (1)
- growth (1)
- hydrogen peroxide (1)
- hydroxylation (1)
- imidization (1)
- imines (1)
- induced phase transition (1)
- kinetics (1)
- luminescent solar concentrators (1)
- macrocycle (1)
- materials (1)
- materials design (1)
- mechanism (1)
- merocyanine (1)
- merocyanine dyes/pigments (1)
- metal complexenes (1)
- metallomacrocycles (1)
- microtubes (1)
- migration (1)
- mobility (1)
- molecular (1)
- molecular capsules (1)
- molecules (1)
- multichromophores (1)
- nanoparticles (1)
- nanorods and nanosheets (1)
- naphthalene diimide (1)
- narrow bandwidth (1)
- near infrared emitter (1)
- near-infrared sensitivity (1)
- non-fullerene acceptors (1)
- noncovalent interactions (1)
- nonfullerene acceptors (1)
- nucleation elongation (1)
- nucleation-elongation (1)
- oligomers (1)
- oligothiophene (1)
- oligothiophenes (1)
- optical materials (1)
- optical spectroscopy (1)
- organic compounds (1)
- organization (1)
- oxidation (1)
- oxygen reduction reaction (1)
- peptide backbone (1)
- perylene (1)
- perylene bisimide dyes (1)
- perylene bisimide hydrogels (1)
- perylene bismide dye (1)
- perylene imide (1)
- perylenebisimide (1)
- perylenebisimide dyes (1)
- photoconductive interlayer (1)
- photoluminescence (1)
- photon‐correlation (1)
- photosenitizers (1)
- platinum complexes (1)
- polycycles (1)
- polymorphism (1)
- porphyrins (1)
- quantum chemical analysis (1)
- reabsorption (1)
- renew-able fuels (1)
- rigidification (1)
- room-temperature phosphorescence (RTP) (1)
- rotational diffusion (1)
- ruthenium catalysts (1)
- scanning probe microscopy (1)
- single crystal structure (1)
- single photon emission (1)
- social self‐sorting (1)
- solar cells (1)
- solar fuels (1)
- solid‐state emission (1)
- solvent effects (1)
- solvent-dependent fluorescence yield (1)
- stability (1)
- starazine (1)
- starphene analogue (1)
- stereochemistry (1)
- structural dynamics (1)
- structure elucidation (1)
- supramolecular materials (1)
- supramolecular polymers (1)
- surface interactions (1)
- sustainable energy source (1)
- systems (1)
- template catalysis (1)
- thermodynamics (1)
- thin-film transistors (1)
- time-resolved impulsive stimulated raman spectroscopy (1)
- triarylborane (1)
- trinuclear (1)
- triplet (1)
- triplet sensitization (1)
- two-dimensional nanostructures (1)
- upramolecular polymerization process (1)
- vacuum processable (1)
- vibrational coherence (1)
- water oxidation catalysis (1)
- π-conjugated systems (1)
- π-π-interactions (1)
- π–π Stacking (1)
Institute
A series of perylene bisimide (PBI) dyes bearing various aryl substituents in 1,6,7,12 bay positions has been synthesized by Suzuki cross-coupling reaction. These molecules exhibit an exceptionally large and conformationally fixed twist angle of the PBI π-core due to the high steric congestion imparted by the aryl substituents in bay positions. Single crystal X-ray analyses of phenyl-, naphthyl- and pyrenyl-functionalized PBIs reveal interlocked π-π-stacking motifs, leading to conformational chirality and the possibility for the isolation of enantiopure atropoisomers by semipreparative HPLC. The interlocked arrangement endows these molecules with substantial racemization barriers of about 120 kJ mol\(^{−1}\) for the tetraphenyl- and tetra-2-naphthyl-substituted derivatives, which is among the highest racemization barriers for axially chiral PBIs. Variable temperature NMR studies reveal the presence of a multitude of up to fourteen conformational isomers in solution that are interconverted via smaller activation barriers of about 65 kJ mol\(^{−1}\). The redox and optical properties of these core-twisted PBIs have been characterized by cyclic voltammetry, UV/Vis/NIR and fluorescence spectroscopy and their respective atropo-enantiomers were further characterized by circular dichroism (CD) and circular polarized luminescence (CPL) spectroscopy.
Bowl-shaped naphthalimide-annulated corannulene as nonfullerene acceptor in organic solar cells
(2020)
An electron-poor bowl-shaped naphthalimide-annulated corannulene with branched alkyl residues in the imide position was synthesized by a palladium-catalyzed cross-coupling annulation sequence. This dipolar compound exhibits strong absorption in the visible range along with a low-lying LUMO level at –3.85 eV, enabling n-type charge transport in organic thin-film transistors. Furthermore, we processed inverted bulk-heterojunction solar cells in combination with the two donor polymers PCE–10 and PM6 to achieve open-circuit voltages up to 1.04 V. By using a blend of the self-assembled naphthalimide-annulated corannulene and PCE–10, we were able to obtain a power conversion efficiency of up to 2.1%, which is to the best of our knowledge the highest reported value for a corannulene-based organic solar cell to date.
A starlike heterocyclic molecule containing an electron‐deficient nonaaza‐core structure and three peripheral isoquinolines locked by three tetracoordinate borons, namely isoquinoline‐nona‐starazine (QNSA), is synthesized by using readily available reactants through a rather straightforward approach. This new heteroatom‐rich QNSA possesses a quasi‐planar π‐backbone structure, and bears phenyl substituents on borons which protrude on both sides of the π‐backbones endowing it with good solubility in common organic solvents. Contrasting to its starphene analogue, QNSA shows intense fluorescence with a quantum yield (PLQY) of up to 62 % in dilute solution.
The quantum efficiency of light emission is a crucial parameter of supramolecular aggregates that can be tuned by the molecular design of the monomeric species. Here, we report on a strong variation of the fluorescence quantum yield due to different phases of aggregation for the case of a perylene bisimide dye. In particular, a change of the dominant aggregation character from H- to J-type within the first aggregation steps is found, explaining the observed dramatic change in quantum yield. This behaviour is rationalised by means of a systematic study of the intermolecular potential energy surfaces using the time-dependent density functional based tight-binding (TD-DFTB) method. This provides a correlation between structural changes and a coupling strength and supports the notion of H- type stacked dimers and J-type stack-slipped dimers. The exciton-vibrational level structure is modelled by means of an excitonic dimer model including two effective vibrational modes per monomer. Calculated absorption and fluorescence spectra are found to be in reasonable agreement with experimental ones, thus supporting the conclusion on the aggregation behaviour.
Conspectus
Nature has established a sustainable way to maintain aerobic life on earth by inventing one of the most sophisticated biological processes, namely, natural photosynthesis, which delivers us with organic matter and molecular oxygen derived from the two abundant resources sunlight and water. The thermodynamically demanding photosynthetic water splitting is catalyzed by the oxygen-evolving complex in photosystem II (OEC-PSII), which comprises a distorted tetramanganese–calcium cluster (CaMn\(_4\)O\(_5\)) as catalytic core. As an ubiquitous concept for fine-tuning and regulating the reactivity of the active site of metalloenzymes, the surrounding protein domain creates a sophisticated environment that promotes substrate preorganization through secondary, noncovalent interactions such as hydrogen bonding or electrostatic interactions. Based on the high-resolution X-ray structure of PSII, several water channels were identified near the active site, which are filled with extensive hydrogen-bonding networks of preorganized water molecules, connecting the OEC with the protein surface. As an integral part of the outer coordination sphere of natural metalloenzymes, these channels control the substrate and product delivery, carefully regulate the proton flow by promoting pivotal proton-coupled electron transfer processes, and simultaneously stabilize short-lived oxidized intermediates, thus highlighting the importance of an ordered water network for the remarkable efficiency of the natural OEC.
Transferring this concept from nature to the engineering of artificial metal catalysts for fuel production has fostered the fascinating field of metallosupramolecular chemistry by generating defined cavities that conceptually mimic enzymatic pockets. However, the application of supramolecular approaches to generate artificial water oxidation catalysts remained scarce prior to our initial reports, since such molecular design strategies for efficient activation of substrate water molecules in confined nanoenvironments were lacking. In this Account, we describe our research efforts on combining the state-of-the art Ru(bda) catalytic framework with structurally programmed ditopic ligands to guide the water oxidation process in defined metallosupramolecular assemblies in spatial proximity. We will elucidate the governing factors that control the quality of hydrogen-bonding water networks in multinuclear cavities of varying sizes and geometries to obtain high-performance, state-of-the-art water oxidation catalysts. Pushing the boundaries of artificial catalyst design, embedding a single catalytic Ru center into a well-defined molecular pocket enabled sophisticated water preorganization in front of the active site through an encoded basic recognition site, resulting in high catalytic rates comparable to those of the natural counterpart OEC-PSII.
To fully explore their potential for solar fuel devices, the suitability of our metallosupramolecular assemblies was demonstrated under (electro)chemical and photocatalytic water oxidation conditions. In addition, testing the limits of structural diversity allowed the fabrication of self-assembled linear coordination oligomers as novel photocatalytic materials and long-range ordered covalent organic framework (COF) materials as recyclable and long-term stable solid-state materials for future applications.
We report the direct imidization of naphthalene and perylene dicarboxylic anhydrides/esters with bulky ortho,ortho‐diaryl‐ and ortho,ortho‐dialkynylaniline derivatives. This imidization method uses n‐butyllithium as a strong base to increase the reactivity of bulky amine derivatives, proceeds under mild reaction conditions, requires only stoichiometric amounts of reactants and gives straightforward access to new sterically crowded rylene dicarboximides. Mechanistic investigations suggest an isoimide as intermediary product, which was converted to the corresponding imide upon addition of an aqueous base. Single‐crystal X‐ray diffraction analyses reveal dimeric packing motifs for monoimides, while two‐side shielded bisimides crystallize in isolated molecules without close π–π‐interactions. Spectroscopic investigations disclose the influence of the bulky substituents on the optical properties in the solid state.
A perylene bisimide dye bearing amide functionalities at the imide positions derived from amino acid L-alanine and a dialkoxy-substituted benzyl amine self-assembles into tightly bound dimers by π-π-stacking and hydrogen bonding in chloroform. In less polar or unpolar solvents like toluene and methylcyclohexane, and in their mixtures, these dimers further self-assemble into extended oligomeric aggregates in an anti-cooperative process in which even numbered aggregates are highly favoured. The stepwise transition from dimers into oligomers can not be properly described by conventional K\(_2\)-K model, and thus a new K\(_2\)-K aggregation model has been developed, which interpretes the present anti-cooperative supramolecular polymerization more appropriately. The newly developed K\(_2\)-K model will be useful to describe self-assembly processes of a plethora of other π-conjugated molecules that are characterized by a favored dimer species.
Herein, we report the one-pot synthesis of an electron-poor nanographene containing dicarboximide groups at the corners. We efficiently combined palladium-catalyzed Suzuki-Miyaura cross-coupling and dehydrohalogenation to synthesize an extended two-dimensional pi-scaffold of defined size in a single chemical operation starting from N-(2,6-diisopropylphenyl)-4,5-dibromo-1,8-naphthalimide and a tetrasubstituted pyrene boronic acid ester as readily accessible starting materials. The reaction of these precursors under the conditions commonly used for Suzuki-Miyaura cross-coupling afforded a C\(_{64}\) nanographene through the formation of ten C-C bonds in a one-pot process. Single-crystal X-ray analysis unequivocally confirmed the structure of this unique extended aromatic molecule with a planar geometry. The optical and electrochemical properties of this largest ever synthesized planar electron-poor nanographene skeleton were also analyzed.
A highly sensitive short-wave infrared (SWIR, λ > 1000 nm) organic photodiode (OPD) is described based on a well-organized nanocrystalline bulk-heterojunction (BHJ) active layer composed of a dicyanovinyl-functionalized squaraine dye (SQ-H) donor material in combination with PC\(_{61}\)BM. Through thermal annealing, dipolar SQ-H chromophores self-assemble in a nanoscale structure with intermolecular charge transfer mediated coupling, resulting in a redshifted and narrow absorption band at 1040 nm as well as enhanced charge carrier mobility. The optimized OPD exhibits an external quantum efficiency (EQE) of 12.3% and a full-width at half-maximum of only 85 nm (815 cm\(^{-1}\)) at 1050 nm under 0 V, which is the first efficient SWIR OPD based on J-type aggregates. Photoplethysmography application for heart-rate monitoring is successfully demonstrated on flexible substrates without applying reverse bias, indicating the potential of OPDs based on short-range coupled dye aggregates for low-power operating wearable applications.
Designing highly efficient purely organic phosphors at room temperature remains a challenge because of fast non-radiative processes and slow intersystem crossing (ISC) rates. The majority of them emit only single component phosphorescence. Herein, we have prepared 3 isomers (o, m, p-bromophenyl)-bis(2,6-dimethylphenyl)boranes. Among the 3 isomers (o-, m- and p-BrTAB) synthesized, the ortho-one is the only one which shows dual phosphorescence, with a short lifetime of 0.8 ms and a long lifetime of 234 ms in the crystalline state at room temperature. Based on theoretical calculations and crystal structure analysis of o-BrTAB, the short lifetime component is ascribed to the T\(^M_1\) state of the monomer which emits the higher energy phosphorescence. The long-lived, lower energy phosphorescence emission is attributed to the T\(^A_1\) state of an aggregate, with multiple intermolecular interactions existing in crystalline o-BrTAB inhibiting nonradiative decay and stabilizing the triplet states efficiently.