Rigid three-dimensional (3D) polycyclic propellanes have garnered interest due to their unique conformational spaces, which display great potential use in selectivity, separation and as models to study through-space e...
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Rigid three-dimensional (3D) polycyclic propellanes have garnered interest due to their unique conformational spaces, which display great potential use in selectivity, separation and as models to study through-space electronic interactions. Herein we report the synthesis of a novel rigid propellane, trinaphtho[3.3.3]propellane triimide, which comprises three imide groups embedded on a trinaphtho[3.3.3]propellane. This propellane triimide exhibits large bathochromic shift, amplified molar absorptivity, enhanced fluorescence, and lower reduction potential when compared to the subunits. Computational and experimental studies reveal that the effective through-space π-orbitals interacting (homoconjugation) occurs between the subunits. Single-crystal XRD analysis reveals that the propellane triimide has a highly quasi- D 3h symmetric skeleton and readily crystallizes into different superstructures by changing alkyl chains at the imide positions. In particular, the porous 3D superstructure with S-shaped channels is promising for taking up ethane (C 2 H 6 ) with very good selectivity over ethylene (C 2 H 4 ), which can purify C 2 H 4 from C 2 H 6 /C 2 H 4 in a single separation step. This work showcases a new class of rare 3D polycyclic propellane with intriguing electronic and supramolecular properties.
Dithioacetals are heavily used in organic, material and medical chemistries, and exhibit huge potential to synthesize degradable or recyclable polymers. However, the current synthetic approaches of dithioacetals and p...
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Dithioacetals are heavily used in organic, material and medical chemistries, and exhibit huge potential to synthesize degradable or recyclable polymers. However, the current synthetic approaches of dithioacetals and polydithioacetals are overwhelmingly dependent on external catalysts and organic solvents. Herein, we disclose a catalyst- and solvent-free acetal-thiol click-like reaction for synthesizing dithioacetals and polydithioacetals. High conversion, higher than acid catalytic acetal-thiol reaction, can be achieved. High universality was confirmed by monitoring the reactions of linear and cyclic acetals (including renewable bio-sourced furan-acetal) with aliphatic and aromatic thiols, and the reaction mechanism of monomolecular nucleophilic substitution (S N 1) and auto-protonation (activation) by thiol was clarified by combining experiments and density functional theory computation. Subsequently, we utilize this reaction to synthesize readily recyclable polydithioacetals. By simple heating and stirring, linear polydithioacetals with w of ~110 kDa were synthesized from acetal and dithiol, and depolymerization into macrocyclic dithioacetal and repolymerization into polydithioacetal can be achieved; through reactive extrusion, a semi-interpenetrating polymer dynamic network with excellent mechanical properties and continuous reprocessability was prepared from poly(vinyl butyral) and pentaerythritol tetrakis(3-mercaptopropionate). This green and high-efficient synthesis method for dithioacetals and polydithioacetals is beneficial to the sustainable development of chemistry.
materials with red room-temperature phosphorescence (RTP) derived from sustainable resources are crucial but rarely reported. Here, we produced red RTP materials from lignin. Lignin was covalently modified with Upy (1...
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materials with red room-temperature phosphorescence (RTP) derived from sustainable resources are crucial but rarely reported. Here, we produced red RTP materials from lignin. Lignin was covalently modified with Upy (1-(6-isocyanatohexyl)-3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl) urea) to obtain Lig-Upy. The Upy in the Lig-Upy promoted the interaction between the aromatic units of lignin and reduced energy gaps of these molecules. As a result, Lig-Upy exhibited red RTP centered at 625 nm with a lifetime of 24.2 ms. Moreover, the hydrogen bonding interactions in Lig-Upy varied when embedded into different matrices, such as polyvinyl alcohol (PVA) or sodium montmorillonite (MTM), inducing a change in RTP wavelength and lifetime. Utilizing these properties, Lig-Upy was used as building blocks for producing materials exhibiting time-dependent phosphorescent colors (TDPCs). Such TDPCs materials have exhibited great potential for visual decorations, information encryption and anti-counterfeiting logos for medicine bottles.
Nachhaltige Kohlenstoffpunkte ( CD s) auf der Basis von Furfural (F- CD ) führten nach Durchführung der Alder-Longo-Reaktion zu einem lichtempfindlichen material. Die gebildete Porphyrineinheit verbindet die...
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Nachhaltige Kohlenstoffpunkte ( CD s) auf der Basis von Furfural (F- CD ) führten nach Durchführung der Alder-Longo-Reaktion zu einem lichtempfindlichen material. Die gebildete Porphyrineinheit verbindet die F-C D s zu einem kovalenten organischen Netzwerk. Dieses heterogene material (P- CD ) wurde mit XPS charakterisiert, was auf den Einbau der jeweiligen C-, N- und O-Einheiten hinweist. Zeitaufgelöste Fluoreszenz einschließlich der Globalanalyse zeigte einen Beitrag von drei verknüpften Komponenten zur Beschreibung der Gesamtdynamik des angeregten Zustands. Die elektrochemischen und photonischen Eigenschaften dieses heterogenen materials ermöglichten eine Photopolymerisation mittels photo-ATRP, bei der entweder CuBr 2 /TPMA, FeBr 3 /Br − oder ein metallfreier Ansatz die kontrollierte Polymerisation aktivierte. Kettenverlängerungsexperimente funktionierten in allen drei Fällen und zeigten die Aktivität der Endgruppe für die Aktivierung der kontrollierten Blockcopolymerisation unter Verwendung von MMA und Styren als Monomere. Die traditionelle radikalische Polymerisation unter Einsatz eines Diaryliodoniumsalzes als Coinitiator scheiterte.
In this contribution, a unique donor-acceptor conjugated organic-small-molecule photothermal material, namely GDPA-QCN, is presented. Bulky dendritic triphenylamine (GDPA) was grafted onto quinoxaline-6,7-dicarbonitri...
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In this contribution, a unique donor-acceptor conjugated organic-small-molecule photothermal material, namely GDPA-QCN, is presented. Bulky dendritic triphenylamine (GDPA) was grafted onto quinoxaline-6,7-dicarbonitrile (QCN) with a phenyl ring as a bridge to form an “umbrella” architecture. Benefited from the particular molecular structure, in solid state, GDPA-QCN molecules adopted a loose packing mode due to the steric effect of “umbrella head” dendritic triphenylamine and flexible molecular structure feature, which allows efficient intramolecular motions and consequently elevates energy dissipation by taking the pathway of thermal deactivation within broad absorption range. The GDPA-QCN solid has high solar-thermal conversion efficiency with an absorption range from 300 to 1100 nm, which can promote superior water purification and electricity generation performance.
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