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Heterocycle‐linked phthalocyanine‐based COFs with close‐packed π–π conjugated structures are a kind of material with intrinsic electrical conductivity, and they are considered to be candidates for photoelectrical devices. Previous studies have revealed their applications for energy storage, gas sensors, and field‐effect transistors. However, their potential application in photodetector is still not fully studied. The main difficulty is preparing high‐quality films. In our study, we found that our newly designed benzimidazole‐linked Cu (II)‐phthalocyanine‐based COFs (BICuPc‐COFs) film can hardly formed with a regular aerobic oxidation method. Therefore, we developed a transfer dehydrogenation method with N‐benzylideneaniline (BA) as a mild reagent. With this in hand, we successfully prepared a family of high crystalline BICuPc‐COFs powders and films. Furthermore, both of these new BICuPc‐COFs films showed high electrical conductivity (0.022–0.218 S/m), higher than most of the reported COFs materials. Due to the broad absorption and high conductivity of BICuPc‐COFs, synaptic devices with small source‐drain voltage (VDS=1 V) were fabricated with response light from visible to near‐infrared. Based on these findings, we expect this study will provide a new perspective for the application of conducting heterocycle‐linked COFs in synaptic devices. [ABSTRACT FROM AUTHOR]

The lack of ambipolar polymers with balanced hole (μh) and electron mobilities (μe) >10 cm2 V−1 s−1 is the main bottleneck for developing organic integrated circuits. Herein, we show the design and synthesis of a π‐extended selenium‐containing acceptor‐dimeric unit, namely benzo[c][1,2,5]selenadiazol‐4‐yl)ethane (BBSeE), to address this dilemma. In comparison to its sulfur‐counterpart, BBSeE demonstrates enlarged co‐planarity, selective noncovalent interactions, polarized Se−N bond, and higher electron affinity. The successful stannylation of BBSeE offers a great opportunity to access acceptor‐acceptor copolymer pN‐BBSeE, which shows a narrower band gap, lower‐lying lowest unoccupied molecular orbital level (−4.05 eV), and a higher degree of backbone planarity. Consequently, the pN‐BBSeE‐based organic transistors display an ideally balanced ambipolar transporting property with μh and μe of 10.65 and 10.72 cm2 V−1 s−1, respectively. To the best of our knowledge, the simultaneous μh/μe values >10.0 cm2 V−1 s−1 are the best performances ever reported for ambipolar polymers. In addition, pN‐BBSeE shows an excellent shelf‐storage stability, retaining over 85 % of the initial mobility values after two months storage. Our study demonstrates the π‐extended acceptor‐dimeric BBSeE is a promising acceptor building block for constructing high‐performance ambipolar polymers applied in next‐generation organic integrated circuit. [ABSTRACT FROM AUTHOR]

Constructing uniform covalent organic framework (COF) film on substrates for electronic devices is highly desirable. Here, a simple and mild strategy is developed to prepare them by polymerization on a solid‐liquid interface. The universality of the method is confirmed by the successful preparation of five COF films with different microstructures. These films have large lateral size, controllable thickness, and high crystalline quality. And COF patterns can also be directly achieved on substrates via hydrophilic and hydrophobic interface engineering, which is in favor of preparing device array. For application studies, the PyTTA‐TPA (PyTTA: 4,4′,4′′,4′′′‐(1,3,6,8‐Tetrakis(4‐aminophenyl)pyrene and TPA: terephthalaldehyde) COF film has a high photoresponsivity of 59.79 μA W−1 at 420 nm for photoelectrochemical (PEC) detection. When employed as an active material for optoelectronic synaptic devices for the first attempt, it shows excellent light‐stimulated synaptic plasticity properties such as short‐term plasticity (STP), long‐term plasticity (LTP), and the conversion of STP to LTP, which can be used to simulate biological synaptic functions. [ABSTRACT FROM AUTHOR]

A family of novel highly π‐extended tetracyano‐substituted acene diimides, named as tetracyanodiacenaphthoanthracene diimides (TCDADIs), have been synthesized using a facile four‐fold Knoevenagel condensation strategy. Unlike conventional cyano substitution reactions, our approach enables access to a large π‐conjugated backbone with the in‐situ formation of four cyano substitutents at room temperature while avoiding extra cyano‐functionalization reactions. TCDADIs decorated with different N‐alkyl substituents present good solubility, near‐coplanar backbones, good crystallinity, and low‐lying lowest unoccupied molecular orbital energies of −4.33 eV, all of which contribute to desirable electron‐transport performance when applied in organic field‐effect transistors (OFET). The highest electron mobility of an OFET based on a 2‐hexyldecyl‐substituted TCDADI single crystal reaches 12.6 cm2 V−1 s−1, which is not only among the highest values for the reported n‐type organic semiconductor materials (OSMs) but also exceeds that of most n‐type OSMs decorated with imide units. [ABSTRACT FROM AUTHOR]

The emulation of functions and behaviors of biological synapses using electronic devices has inspired the development of artificial neural networks (ANNs) in biomedical interfaces. Despite the achievements, artificial synapses that can be selectively responsive to non‐electroactive biomolecules and directly operate in biological environments are still lacking. Herein, we report an artificial synapse based on organic electrochemical transistors and investigate the selective modulation of its synaptic plasticity by glucose. The enzymatic reaction between glucose and glucose oxidase results in long‐term modulation of the channel conductance, mimicking selective binding of biomolecules to their receptors and consequent long‐term modulation of the synaptic weight. Moreover, the device shows enhanced synaptic behaviors in the blood serum at a higher glucose concentration, which suggests its potential application in vivo as artificial neurons. This work provides a step towards the fabrication of ANNs with synaptic plasticity selectively mediated by biomolecules for neuro‐prosthetics and human‐machine interfaces. [ABSTRACT FROM AUTHOR]

Facile synthesis and post‐processing of covalent organic frameworks (COFs) under mild synthetic conditions are highly sought after and important for widespread utilizations in catalysis and energy storage. Here we report the synthesis of the chemically stable aza‐fused COFs BPT‐COF and PT‐COF by a liquid‐phase method. The process involves the spontaneous polycondensation of vicinal diamines and vicinal diketones, and is driven by the near‐equilibrium growth of COF domains at a very low monomer concentration. The method permits in situ assembly of COFs and COF‐GO hybrid materials and leads to the formation of a uniform conducting film on arbitrary substrates on vacuum filtration. When used as electrocatalysts, the as‐prepared membranes show a fast hydrogen evolution reaction (HER) with a low overpotential (45 mV at 10 mA cm−2) and a small Tafel slope (53 mV dec−1), which are the best among metal‐free catalysts. Our results may open a new route towards the preparation of highly π‐conjugated COFs for multifunctional applications. [ABSTRACT FROM AUTHOR]

2D metal‐organic framework (MOF) film as the active layer show promising application prospects in various fields including sensors, catalysis, and electronic devices. However, exploring the application of 2D MOF film in the field of artificial synapses has not been implemented yet. In this work, we fabricated a novel 2D MOF film (Cu‐THPP, THPP=5,10,15,20‐Tetrakis(4‐hydroxyphenyl)‐21H,23H‐porphine), and further used it as an active layer to explore the application in the simulation of human brain synapses. It shows excellent light‐stimulated synaptic plasticity properties, and exhibits the foundation function of synapses such as long‐term plasticity (LTP), short‐term plasticity (STP), and the conversion of STP to LTP. Most critically, the MOF based artificial synaptic device exhibits an excellent stability in atmosphere. This work opens the door for the application of 2D MOF film in the simulation of human brain synapses. [ABSTRACT FROM AUTHOR]

2D metal‐organic framework (MOF) film as the active layer show promising application prospects in various fields including sensors, catalysis, and electronic devices. However, exploring the application of 2D MOF film in the field of artificial synapses has not been implemented yet. In this work, we fabricated a novel 2D MOF film (Cu‐THPP, THPP=5,10,15,20‐Tetrakis(4‐hydroxyphenyl)‐21H,23H‐porphine), and further used it as an active layer to explore the application in the simulation of human brain synapses. It shows excellent light‐stimulated synaptic plasticity properties, and exhibits the foundation function of synapses such as long‐term plasticity (LTP), short‐term plasticity (STP), and the conversion of STP to LTP. Most critically, the MOF based artificial synaptic device exhibits an excellent stability in atmosphere. This work opens the door for the application of 2D MOF film in the simulation of human brain synapses. [ABSTRACT FROM AUTHOR]

Owing to their excellent physical and electrical properties, metal–organic framework (MOF) materials with well‐defined supramolecular structures have received extensive research attention. However, the fabrication of large‐area two‐dimensional (2D) MOF films is still a significant challenge. Herein, we propose a novel electrochemical (EC) synthesis method for the preparation of large‐area Cu3(HHTP)2 MOF film on single‐crystal Cu (100) anode. The surface reaction was achieved via charge‐induced molecular assembly. The synthesized MOF film exhibited a high crystalline quality with an electrical conductivity of approximately 0.087 S cm−1, which was around 1000 times larger than the previously reported values for the same material prepared by the interface method. In addition, Cu2(MTCP), Cu3(BTPA)2, and Cu3(TPTC)2 MOF films were synthesized on Cu foil with the same strategy, which confirmed the universality of the proposed method. This controllable EC method can be effectively applied to the industrial‐scale production of 2D MOF films on Cu foil. [ABSTRACT FROM AUTHOR]

The sensitivity of conventional thin‐film OFET‐based sensors is limited by the diffusion of analytes through bulk films and remains the central challenge in sensing technology. Now, for the first time, an ultrasensitive (sub‐ppb level) sensor is reported that exploits n‐type monolayer molecular crystals (MMCs) with porous two‐dimensional structures. Thanks to monolayer crystal structure of NDI3HU‐DTYM2 (NDI) and controlled formation of porous structure, a world‐record detection limit of NH3 (0.1 ppb) was achieved. Moreover, the MMC‐OFETs also enabled direct detection of solid analytes of biological amine derivatives, such as dopamine at an extremely low concentration of 500 ppb. The remarkably improved sensing performances of MMC‐OFETs opens up the possibility of engineering OFETs for ultrasensitive (bio)chemical sensing. [ABSTRACT FROM AUTHOR]

Reported herein is a rhodium(III)‐catalyzed three‐component annulation reaction of simple pyridines, alkynes, and 1,2‐dichloroethane (DCE), affording a streamlined pathway to diverse ring‐fused pyridiniums. DCE not only serves as a vinyl equivalent but also as an in situ activating agent for pyridine C2−H activation. A cationic five‐membered rhodacycle complex has been isolated and proposed as a possible intermediate. This strategy can be extended to other N‐containing heteroarenes for the synthesis of multiring‐fused pyridiniums. These multicomponent reactions exhibit excellent regioselectivity for 1,3‐diynes, paving a path to the cascade cyclization of 3‐fluoropyridine or N‐methylpyridin‐3‐amine with 1,3‐diynes for the construction of brand‐new tricyclic‐fused pyrano‐ or hydropyridoquinolizinium salts. These ionic fluorophores have been investigated as potential biomarkers. Triple agent: Disclosed herein is a rhodium(III)‐catalyzed multicomponent reaction of simple pyridines, alkynes, and 1,2‐dichloroethane (DCE) to afford a streamlined pathway to diverse ring‐fused pyridiniums. DCE serves as a vinyl equivalent and an in situ activating agent for pyridine C2−H activation, as well as a solvent. [ABSTRACT FROM AUTHOR]

Abstract: Developing an efficient single‐atom material (SAM) synthesis and exploring the energy‐related catalytic reaction are important but still challenging. A polymerization–pyrolysis–evaporation (PPE) strategy was developed to synthesize N‐doped porous carbon (NPC) with anchored atomically dispersed Fe‐N4 catalytic sites. This material was derived from predesigned bimetallic Zn/Fe polyphthalocyanine. Experiments and calculations demonstrate the formed Fe‐N4 site exhibits superior trifunctional electrocatalytic performance for oxygen reduction, oxygen evolution, and hydrogen evolution reactions. In overall water splitting and rechargeable Zn–air battery devices containing the Fe‐N4 SAs/NPC catalyst, it exhibits high efficiency and extraordinary stability. This current PPE method is a general strategy for preparing M SAs/NPC (M=Co, Ni, Mn), bringing new perspectives for designing various SAMs for catalytic application. [ABSTRACT FROM AUTHOR]

Frontispiece: Near-Equilibrium Growth of Chemically Stable Covalent Organic Framework/Graphene Oxide Hybrid Materials for the Hydrogen Evolution Reaction Keywords: covalent organic frameworks; hydrogen evolution reaction; near-equilibrium growth; two-dimensional nanomaterials EN covalent organic frameworks hydrogen evolution reaction near-equilibrium growth two-dimensional nanomaterials 1 1 1 01/06/22 20220110 NES 220110 B Covalent Organic Frameworks b Near-equilibrium growth of chemically stable covalent organic framework-graphene oxide hybrid materials for the hydrogen evolution reaction is reported in the Communication by Jianyi Chen, Jichen Dong, Yunqi Liu et al. (e202113067). Covalent organic frameworks, hydrogen evolution reaction, near-equilibrium growth, two-dimensional nanomaterials. [Extracted from the article]