Synthesis, Structure, and Properties of Tetrabenzo[7]circulene

Tetrabenzo­[7]­circulene, a new member of aromatic saddles, was conveniently synthesized from 2-(1-naphthoyl)­benzoic acid with the seven-membered ring constructed at an early stage of the synthesis. This method, upon minor modification, was also useful for synthesis of thiophene-annulated [7]­circulenes. The structures of tetrabenzo[7]­circulene and [7]­circulene were compared in terms of symmetry, flexibility, and curvature on the basis of DFT calculations and X-ray crystallography. It was also found that tetrabenzo[7]­circulene functioned as a p-type semiconductor in thin-film transistors and cocrystallized with C₆₀

Bio-Inspired Synthetic Nanovesicles for Glucose-Responsive Release of Insulin

A new glucose-responsive formulation for self-regulated insulin delivery was constructed by packing insulin, glucose-specific enzymes into pH-sensitive polymersome-based nanovesicles assembled by a diblock copolymer. Glucose can passively transport across the bilayer membrane of the nanovesicle and be oxidized into gluconic acid by glucose oxidase, thereby causing a decrease in local pH. The acidic microenvironment causes the hydrolysis of the pH sensitive nanovesicle that in turn triggers the release of insulin in a glucose responsive fashion. In vitro studies validated that the release of insulin from nanovesicle was effectively correlated with the external glucose concentration. In vivo experiments, in which diabetic mice were subcutaneously administered with the nanovesicles, demonstrate that a single injection of the developed nanovesicle facilitated stabilization of the blood glucose levels in the normoglycemic state (<200 mg/dL) for up to 5 days

Synthesis, Molecular Packing, and Thin Film Transistors of Dibenzo[<i>a</i>,<i>m</i>]rubicenes

We herein report an efficient synthesis of dibenzo­[<i>a</i>,<i>m</i>]­rubicene, a new member of nonplanar cyclopenta-fused polycyclic aromatic hydrocarbon, and its derivatives. It is found that the conformation and molecular packing of dibenzo­[<i>a</i>,<i>m</i>]­rubicenes in the solid state can be tuned by the substituting groups, and the silylethynylated derivatives of dibenzo­[<i>a</i>,<i>m</i>]­rubicenes function as p-type organic semiconductors in solution-processed thin film transistors with field effect mobility of up to 1.0 cm² V^–1 s^–1

Synthesis, Molecular Packing, and Thin Film Transistors of Dibenzo[<i>a</i>,<i>m</i>]rubicenes

We herein report an efficient synthesis of dibenzo­[<i>a</i>,<i>m</i>]­rubicene, a new member of nonplanar cyclopenta-fused polycyclic aromatic hydrocarbon, and its derivatives. It is found that the conformation and molecular packing of dibenzo­[<i>a</i>,<i>m</i>]­rubicenes in the solid state can be tuned by the substituting groups, and the silylethynylated derivatives of dibenzo­[<i>a</i>,<i>m</i>]­rubicenes function as p-type organic semiconductors in solution-processed thin film transistors with field effect mobility of up to 1.0 cm² V^–1 s^–1

Proton-Induced Dysfunction Mechanism of Cathodes in an Aqueous Lithium Ion Battery

The proton-induced dysfunction mechanism of cathodes in aqueous lithium ion batteries is investigated by combining both experimental and theoretical research. We have found the electrochemical stability of the cathodes in a Li⁺-containing aqueous electrolyte solution is critically dependent on the pH value of the solution. The cyclic voltammograms of the cathodes show that the cathodes become dysfunctional when the pH of the solution decreases right below a certain value. We find that the competition reactions to the cathodes of the H⁺ and Li⁺ in the solution dominate whether Li⁺ or H⁺ would be intercalated. Thermodynamic analysis proves that the critical pH, which divide the normal and dysfunctional behaviors, is determined by both the difference of the binding energies of Li⁺ and H⁺ cations to the cathodes and the chemical potentials of the Li⁺ and H⁺ in the solution

Synthesis, Molecular Packing, and Thin Film Transistors of Dibenzo[<i>a</i>,<i>m</i>]rubicenes

We herein report an efficient synthesis of dibenzo­[<i>a</i>,<i>m</i>]­rubicene, a new member of nonplanar cyclopenta-fused polycyclic aromatic hydrocarbon, and its derivatives. It is found that the conformation and molecular packing of dibenzo­[<i>a</i>,<i>m</i>]­rubicenes in the solid state can be tuned by the substituting groups, and the silylethynylated derivatives of dibenzo­[<i>a</i>,<i>m</i>]­rubicenes function as p-type organic semiconductors in solution-processed thin film transistors with field effect mobility of up to 1.0 cm² V^–1 s^–1

Synthesis, Molecular Packing, and Thin Film Transistors of Dibenzo[<i>a</i>,<i>m</i>]rubicenes

We herein report an efficient synthesis of dibenzo­[<i>a</i>,<i>m</i>]­rubicene, a new member of nonplanar cyclopenta-fused polycyclic aromatic hydrocarbon, and its derivatives. It is found that the conformation and molecular packing of dibenzo­[<i>a</i>,<i>m</i>]­rubicenes in the solid state can be tuned by the substituting groups, and the silylethynylated derivatives of dibenzo­[<i>a</i>,<i>m</i>]­rubicenes function as p-type organic semiconductors in solution-processed thin film transistors with field effect mobility of up to 1.0 cm² V^–1 s^–1

Solution-Processed Ambipolar Organic Thin-Film Transistors by Blending p- and n‑Type Semiconductors: Solid Solution versus Microphase Separation

Here, we report solid solution of p- and n-type organic semiconductors as a new type of p–n blend for solution-processed ambipolar organic thin film transistors (OTFTs). This study compares the solid-solution films of silylethynylated tetraazapentacene <b>1</b> (acceptor) and silylethynylated pentacene <b>2</b> (donor) with the microphase-separated films of <b>1</b> and <b>3</b>, a heptagon-embedded analogue of <b>2</b>. It is found that the solid solutions of (<b>1</b>)_<i>x</i>(<b>2</b>)_1–<i>x</i> function as ambipolar semiconductors, whose hole and electron mobilities are tunable by varying the ratio of <b>1</b> and <b>2</b> in the solid solution. The OTFTs of (<b>1</b>)_0.5(<b>2</b>)_0.5 exhibit relatively balanced hole and electron mobilities comparable to the highest values as reported for ambipolar OTFTs of stoichiometric donor–acceptor cocrystals and microphase-separated p-n bulk heterojunctions. The solid solution of (<b>1</b>)_0.5(<b>2</b>)_0.5 and the microphase-separated blend of <b>1:3</b> (0.5:0.5) in OTFTs exhibit different responses to light in terms of absorption and photoeffect of OTFTs because the donor and acceptor are mixed at molecular level with π–π stacking in the solid solution

Probing the Crystal Plane Effect of Co₃O₄ for Enhanced Electrocatalytic Performance toward Efficient Overall Water Splitting

Identifying effective methods to enhance the properties of catalysts is urgent to broaden the scanty technologies, so far. Herein, we synthesized four Co₃O₄ crystals with different crystal planes and explored the crystal planes’ effects on electrochemical water splitting through theoretical and experimental studies for the first time. The results illustrate that the correlation of catalytic activity is established as {111} > {112} > {110} > {001}. Co₃O₄ crystals exposed with {111} facets show the highest OER (oxygen evolution reaction) and HER (hydrogen evolution reaction) activities. Upon fabrication in an alkaline electrolyzer, the bifunctional {111}∥{111} couple manifests the highest catalytic activity and satisfying durability for overall water splitting. Density functional theory (DFT) explains that the {111} facet possesses the biggest dangling bond density, highest surface energy, and smallest absolute value of Δ<i>G</i>_H*, leading to the enhanced electrocatalytic performance. This work will broaden our vision to improve the activity of various electrocatalysts by selectively exposing the specific crystal planes

New Efficient Electrocatalyst for the Hydrogen Evolution Reaction: Erecting a V₂Se₉@Poly(3,4-ethylenedioxythiophene) Nanosheet Array with a Specific Active Facet Exposed

To obtain catalysts with remarkable activity for the hydrogen evolution reaction (HER), rational design and synthesis of catalysts with rich active sites are very urgent. Herein, we reported, for the first time, V₂Se₉ nanosheet arrays exposed with the highly active (100) facet as a new efficient catalyst for HER. The highly active but thermodynamically instable (100) facet was converted from V₂O₅ based on a low crystal-mismatch strategy. Furthermore, conductive poly­(3,4-ethylenedioxythiophene) (PEDOT) acting as a co-catalyst further contributed to the redistribution of charge and reduction of hydrogen adsorption energy. Due to the strong synergistic effect between V₂Se₉ and PEDOT, the resulting material, noted as V₂Se₉@PEDOT NSs/NF, exhibited excellent electrocatalytic performance among selenide catalysts, for example, a small overpotential of 72 mV at 10 mA cm^–2, a low Tafel slope of 36.5 mV dec^–1, and remarkable durability. Simultaneously, density functional theory (DFT) computations proved that the adsorption free energy of H* (Δ<i>G</i>_H*) for V₂Se₉@PEDOT NSs/NF (0.09 eV) is comparable to that of Pt (around 0.09 eV)