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Purposive Assembling of Poly(3-hexylthiophene) onto Chemically Treated Multi-Wall Carbon Nanotube versus Reduced Graphene Oxide
摘要： Surfaces of multi-walled carbon nanotubes (CNTs) and reduced graphene oxide (rGO) nanosheets were chemically modified to design distinct donor-acceptor nano-hybrids having different morphologies and orientations. In unmodified CNTs and their derivatives functionalized with 2-hydroxymethyl thiophene (CNT-f-COOTh) and grafted with poly(3-dodecylthiophene) (CNT-g-PDDT), double-fibrillar, shish-kebab, and stem-leaf nanostructures were decorated. Furthermore, rGO nanosheets functionalized with 2-thiophene acetic acid (rGO-f-TAA) and grafted with poly(3-dodecylthiophene) (rGO-g-PDDT) were prepared to study differences in CNT and rGO supramolecules. Three types of orientations subsuming face-on, edge-on, and flat-on were detected in nano-hybrids based on CNT and rGO. Morphology (fibrillar) and orientation (face-on) of poly(3-hexylthiophene) (P3HT) assemblies were similar onto unmodified CNT and rGO nanostructures. Although patternings of P3HT chains were completely different onto functionalized CNT and rGO (shish-kebab versus nanocrystal decorated nanosheets), edge-on orientation was detected in CNT-f-COOTh/P3HT and rGO-f-TAA/P3HT nano-hybrids. In CNT-g-PDDT/P3HT and rGO-g-PDDT/P3HT systems, P3HT chains were extendedly assembled onto grafted carbonic materials; however, their different natures reflected stem-leaf and patched-like configurations, respectively. For unmodified, functionalized, and grafted CNT and rGO patterned with P3HT chains, a photoluminescence quenching was detected for a donor-acceptor nature. Owing to flat-on oriented P3HTs, the best photoluminescence quenching, thereby the best donating-accepting features were detected for CNT-g-PDDT/P3HT and rGO-g-PDDT/P3HT supramolecules.
关键词： donor-acceptor,morphology,rGO,nano-hybrid,CNT
更新于2025-09-09 09:28:46
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Synthesis of Novel Donor-Acceptor Type Molecule Based on Phenothiazine Unit for Organic Light-Emitting Materials
摘要： A novel conjugated organic molecule based on central phenothiazine unit as an electronic donor and aldehyde group termini as an electronic acceptor has been designed and constructed. Optical spectra show that, the absorption and fluorescence spectra of M2 are large red-shifted relative to M1 in both states, however, from solution to the solid state, the absorption maxima and emission maxima of M1 and M2 are in the opposite trends (blue-shift). The fluorescence spectra exhibit that the emission maxima of M1 and M2 which range from 485 nm to 588 nm belong to green light region. As expected, the target compounds should be a promising green light-emitting material for applications in organic light-emitting diodes (OLEDs).
关键词： Molecule,Donor-acceptor,Phenothiazine unit,Light-emitting materials
更新于2025-09-09 09:28:46
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[1]Benzothiophene-Fused Chiral Spiro Polycyclic Aromatic Compounds: Optical Resolution, Functionalization, and Optical Properties
摘要： Spiro polycyclic aromatic compounds have been known as rigid chiral scaffolds. In order to extend their applications, an efficient preparation route to enantiopure derivatives is highly required. Here, we design 10,10′-spirobi[indeno[1,2-b][1]benzothiophene]-7,7′-diol to achieve efficient optical resolution. The compound was successfully synthesized and resolved by chiral HPLC on a semipreparative scale. The absolute configuration of its enantiopure isomer was determined through single crystal X-ray structure analysis of its derivative. The compound was also transformed into its derivatives with donor–acceptor (D–A) type systems. The obtained chiral D–A type molecules exhibited remarkable solvent-dependence fluorescence and were found to be solvent-sensitive circularly polarized luminescent materials. These results clearly demonstrated the utility of 10,10′-spirobi[indeno[1,2-b][1]benzothiophene]-7,7′-diol as a versatile building block for chiral spiro polycyclic aromatic compounds.
关键词： donor–acceptor (D–A) type systems,circularly polarized luminescent materials,optical resolution,Spiro polycyclic aromatic compounds,chiral HPLC
更新于2025-09-09 09:28:46
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Importance of Chromophore Rigidity on the Efficiency of Blue Thermally Activated Delayed Fluorescence Emitters
摘要： Four new symmetrical donor?acceptor?donor (D?A?D)-type molecules are reported with diphenylamine (DPA) or 10,11-dihydro-5H-dibenz[b,f ]azepine (Az) as electron donors and 9,9-dimethylthioxanthene-S,S-dioxide (TXO2) as the electron acceptor. The donors are attached at different positions on the acceptor core: either para or meta to the sulfone unit. This series provides new insights into the effects of chromophore rigidity/flexibility on the efficiency of thermally activated delayed fluorescence (TADF). The molecules have been characterized by X-ray crystallography, by in-depth photophysical studies, and by theoretical calculations. The clear differences observed in the photophysical properties when using DPA or Az as a donor are shown to originate from different geometries of the donor unit which, in turn, influence the geometry of the nitrogen lone pair and the donating strength of the corresponding fragment. Thus, a para-substituted Az derivative demonstrated blue TADF in polar media, while the compounds with more flexible DPA units did not show delayed fluorescence. To obtain deep-blue emitters, weaker donating units are needed. A more flexible donor unit leads to increased local excited state (donor) LE emission and reduced TADF. However, a certain amount of flexibility has to be present to ensure deep-blue TADF.
关键词： chromophore rigidity,blue emitters,donor-acceptor-donor,photophysical properties,thermally activated delayed fluorescence
更新于2025-09-04 15:30:14
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Dithienobenzimidazole‐containing conjugated donor–acceptor polymers: Synthesis and characterization
摘要： The synthesis of two new conjugated polymers based on the relatively under-exploited monomer, 5,8-dibromo-2-[5-(2-hexyldecyl)-2-thienyl]-1H-dithieno[3,2-e:20,30-g]benzimidazole (dithienobenzimidazole, DTBI), and either 4,7-bis[4-hexyl-5-(trimethylstannyl)-2-thienyl]-2,1,3-benzothiadiazole (BTD) or 2,6-bis(trimethylstannyl)-4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b0]dithiophene (BDT) is described. The polymers were synthesized via Stille polycondensation and characterized by traditional methods (1H NMR, gel-permeation chromatography, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, thermal gravimetric analysis, differential scanning calorimetry, ultraviolet–visible spectroscopy, photoluminescence, and cyclic voltammetry). Prior to their synthesis, trimer structures were modeled by DFT calculations facilitating a further understanding of the systems’ electronic and geometric structure. Polymers were titrated with acid and base to take advantage of their amphiprotic imidazole moiety and their optical response monitored with ultraviolet–visible spectroscopy. Finally, pristine polymer thin-films were treated with acid and base to evaluate (de)protonation’s effect on system electronics, but thin-film degradation was encountered.
关键词： addition polymerization,synthesis,conjugated,conducting polymers,semiconducting polymer,dithienobenzimidazole,ionomers,donor–acceptor
更新于2025-09-04 15:30:14
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Stable, carrier separation tailorable conjugated microporous polymers as a platform for highly efficient photocatalytic H2 evolution
摘要： The molecular design of highly photo-functional polymers with high charge separation efficiency and wide spectral absorption are long term quest for photocatalysis. Herein, we design and develop a series of nitrogen-containing conjugated microporous polymers (N-CMPs) with tailored donor-acceptor units for enhancing charge separation and light harvesting for visible light photocatalytic H2 production. By alternating the substitution position (o-, m-, or p-) and the number of electron donor (carbazole, diphenylamine) and acceptor (cyano) units on the 3D-core structure, a series of N-CMPs with adjustable donor-acceptor (D-A) charge separation efficiencies and tuneable band gaps in the range of 1.64-2.29 eV were obtained, enabling the precise control of the photocatalytic activity at the molecular level. The optimized N-CMP (4-CzPN) exhibits a higher visible light H2 production rate at 2103.2 μmol/h·g and the apparent quantum yield (AQY) at 420 nm reaches 6.4%. Furthermore, the 4-CzPN photocatalyst maintains excellent durability and recycling performance under 25 h continued light irradiation. The outstanding photocatalytic performance of the optimized N-CMPs with D-A structure is attributed to the enhanced polarity and conjugated degree of their core structure, which promotes charge separation and light absorption.
关键词： light absorption,donor-acceptor units,photocatalytic H2 production,conjugated microporous polymers,charge separation
更新于2025-09-04 15:30:14