During the past 170 years, organic small molecular fluorescent dyes had been widely applied in fluorescence labeling, fluorescence probes and bioimaging. And their structures and performances continually evolved with development of synthetic method and application. However, the emerging super-resolution imaging put forward higher requirements at brightness, stability and switching performance of organic small molecular fluorescent dyes, which also offers new opportunity for developing novel dyes at the same time. So, chemists presently pay more attentions on brightness and photostability. Twisted intramolecular charge transfer (TICT), the major nonradiative decay channel in organic small molecular fluorescent dyes, seriously decrease brightness and photostability. Therefore, inhibiting TICT has became the crucial strategy to develop organic small molecular fluorescent dyes towards super-resolution imaging. This review will firstly demonstrate mechanism and development of TICT and emphatically introduce the progress in improving organic small molecular fluorescent dyes based on inhibiting TICT.

With the advance of industrialization of human society, fossil energy has been overconsumed, and excessive carbon dioxide has been discharged into the atmosphere, resulting in energy crisis and environmental issues. The preparation of high value-added fine chemicals by electrocatalytic reduction of carbon dioxide is one of the directions to explore the establishment of artificial carbon cycle, which has attracted extensive attention in fundamental research and industrial applications. Structural design and preparation of electrocatalysts with high activity, selectivity and stability are of great significance to achieve efficient catalytic performance for carbon dioxide reduction. In recent years, many studies have reported the structural design ideas and application cases of catalyst and electrode materials, and remarkable progress has been made. In this review, the regulation strategies of catalyst structure and electrode structure are summarized from four aspects: size effect, surface characteristics, defect engineering and multi-stage structure, and the development of electrocatalytic carbon dioxide reduction is prospected.

Electrochemical production of H₂O₂ from O₂ via the two-electron reduction reaction (2e-ORR) is a green and safe process that is being heavily investigated. Zeolitic imidazolate frameworks (ZIF) as a subclass of metal-organic frameworks (MOFs) have attracted enormous scientific interests due to their high porosity, excellent mechanical stability, tunable surface properties, and exceptional chemical and thermal stabilities. Herein, a series of pyrolyzed ZIF catalysts (p-ZIF) were synthesized by treating 2-methylimidazole zinc salt (ZIF-8) at high temperatures (900, 950 and 1000 ℃). During pyrolysis, zinc was vaporized, leaving the metal-free nitrogen-doped porous graphitic carbon materials. The effects of the pyrolysis temperature on the structure and catalytic performance of the p-ZIF catalysts in 2e-ORR were systematically studied. In 2e-ORR in an acidic electrolyte, the p-ZIF catalysts displayed low overpotential, low Tafel slope, and negligible activity loss after 3000 cycles of accelerated durability testing (ADT). In particular, the p-ZIF-950 catalyst possessed the highest H₂O₂ partial current of 0.185 mA at 0 V vs. RHE, followed by the p-ZIF-900 (0.146 mA) and p-ZIF-1000 (0.135 mA) catalysts. The H₂O₂ selectivity over the p-ZIF-950 catalyst was also constantly higher than those over the other two p-ZIF catalysts across the potential range investigated and maximized at 89.2%. Highly efficient and durable H₂O₂ production was demonstrated on the p-ZIF-950 catalyst by the linear accumulation of H₂O₂ to 522 mmol•g_cat^-1 within 6 h, translating to an H₂O₂ production rate of 87 mmol•g_cat^-1•h^-1. The morphology, composition, carbon defect, texture, and surface chemical state were characterized by techniques such as transmission electron microscopy (TEM), elemental analysis, Raman spectroscopy, N₂ physisorption, and X-ray photoelectron spectroscopy (XPS). The p-ZIF catalysts not only nicely carried over the regular rhombic dodecahedral morphology of ZIF-8, but also possessed abundant amount of nitrogen, high specific surface area, and hierarchical pore structure. According to the characterization results, the specific surface area and carbon defect are unlikely the key factors that determine the catalytic performance, while the evolutions of the average pore size and surface content of graphitic N mimicked those of the H₂O₂ partial current and selectivity on the p-ZIF catalysts. In light of the literature works, the large pore size is proposed to facilitate the in-diffusion of O₂ and out-diffusion of H₂O₂, while the graphitic N is able to enhance the activation of O₂ and desorption of H₂O₂, both of which are beneficial to the kinetics of the 2e-ORR reaction.

Coupling or condensation reagents that could be used to promote the condensation of carboxylic acids with amines to furnish amide bonds play crucial roles in solid phase peptide synthesis (SPPS) of peptides and peptide-based derivatives. Compared with traditional coupling reagents used in SPPS such as 1-hydroxy-7-azabenzotriazole (HOAt) and 1-hydroxybenzotriazole (HOBt), the novel N,N'-diisopropylcarbodiimide (DIC)/ethyl 2-cyano-2-(hydroxyimino) acetate (Oxyma) condensation system has advantages of inexpensiveness, safety, high coupling efficiency, low racemic rate, and compatibility with manual and automatic peptide synthesis represented by microwave-assisted SPPS. However, the effects of different reaction temperatures (e.g. 28, 50, and 75 ℃) on the coupling efficiency of DIC/Oxyma and on the easily oxidized amino acids such as methionine (Met) remain to be further investigated. The transient receptor potential ankyrin 1 (TRPA1) channel plays an important role in temperature perception, auditory perception, and inflammatory pain. As a novel non-covalently TRPA1-specific agonist, Wasabi Receptor Toxin (WaTx) that consists of 33 amino acid residues and two pairs of disulfide bonds is considered as an important molecular tool to study the opening mechanism and function of TRPA1. In this study, 2-(6-chloro-1H-benzotriazole-1-yl)-1,1,3,3-tetramethylaminiumhexa-fluorophosphate (HCTU)/N,N'-diisopropyl- ethylamine (DIEA) and DIC/Oxyma condensation systems were separately utilized to explore the synthetic efficiency of linear WaTx and the oxidative degree of Met residues at different temperatures. The robustness of DIC/Oxyma condensation system was validated by the rapid manual synthesis of linear WaTx. The one-step and two-step oxidative folding strategies were separately applied for the construction of two pairs of disulfide bridges, affording the active WaTx, which was further confirmed by circular dichroism and calcium fluorescence assay. In this study, a moderate, efficient synthesis and renaturation folding method of WaTx was established. Moreover, the effects of different reaction temperatures on the synthetic efficiency of DIC/Oxyma and on amino acid residues oxidization were compared for the first time. From the aspects of reaction efficiency (represented by the timescale of the overall Fmoc deprotection-washing-amino acid coupling SPPS cycle), amino acid residues oxidization and synthetic cost, n(Fmoc-amino acid):n(DIC):n(Oxyma)=3:6:3 under 50 ℃ should be the ideal reaction condition. This work provides both an imperative complement for SPPS and a particularly useful strategy for the manual efficient synthesis of disulfide-containing peptides with easily oxidized groups.

Ring-opening metathesis polymerization (ROMP) is a strategy in which monocyclic or polycyclic olefins undergo ring-opening polymerization to form functionalized polymers. ROMP has been recognized as a powerful synthetic strategy for the synthesis of advanced polymeric materials. Recently, star polymers are receiving intense interests in materials science and nanotechnology in both academic and industrial fields due to the unique structure and property. In this review, the applications of ROMP in the synthesis of star polymers are discussed in terms of methods of polymerization, monomers, initiators and crosslinking agents. Moreover, the application fields and prospects of the ROMP synthesized star polymers, and the advantages and limitations of various ROMP methods are also presented. This work aims to promote development of ROMP in the synthesis of star-shaped polymers, provide a new scientific research approach for the synthesis of functionally complicated star-shaped polymers, and contribute to the acceleration of the commercialization of star-shaped polymer materials.

Organic electrochemical synthesis has become a useful and environmentally friendly alternative to traditional organic synthesis and has been applied to oxidation, reduction, or redox neutral transformation. By dialing in the electric current or electrode potential, it is possible to achieve some challenging transformations under mild reaction conditions. With the increasing awareness of energy efficiency and environmental protection, organic electrochemical synthesis has attracted much attention in recent years. However, electrochemical synthesis faces several challenges including electrode passivation, limited reaction types, the difficulty of controlling reactivity and selectivity, and so on. This review focuses on electrochemical synthesis in organic solution system, and it summarizes recent efforts in addressing these challenges through direct electrolysis and indirect electrolysis. In direct electrolysis, the strategies include the rational design of electrochemical electrolysis reactions, change of electrochemical electrolysis modes and equipment, or merging of electrochemical technology with other novel synthetic technologies. In terms of indirect electrolysis, organic compounds or transition metals are mainly used as molecular electrocatalysts to shuttle the electrons between electrodes and substrates and control the reaction reactivity and selectivity, affording some challenging chemical transformations.

Amines have a wide variety and are readily available. Due to the larger C—N bond energy of amines, C—N bond of amines generally needs to be activated before cleavage. In recent years, a variety of activation methods of amino groups have been developed. Among the activation methods, converting amines into quaternary ammonium salts has certain advantages of easy preparation and stable storage. In last decade, quaternary ammonium salts derived from aromatic amines and benzylamines have made great progress in the study of constructing various C—X bonds via cleavage of C—N bond. This review mainly discusses the formation of C—X bonds of quaternary ammonium salts via cleavage of C—N bond with or without transition metal catalysts over the past few years. Via C—N bond breakage, quaternary ammonium salts can construct C—B bond, C—C bond, C—N bond, C—O bond, C—Si bond, C—P bond, C—S bond, C—Se bond, and so on. And thus borates, aromatics, alkanes, ethers, amines, silanes, phosphines, thioethers, disulfides, selenoethers, diselenides and other compounds are synthesized. Moreover, if the quaternary ammonium salts derived from chiral benzylamines are adopted, a variety of highly enantiopure chiral organic compounds are obtained. The chiralities of quaternary ammonium salts are excellently kept in the products, and S_N2 type configuration reversal occurs for all of the reported reactions.

Nowadays, under the background of energy shortage and “double carbon”, clean and efficient utilization of energy is very important. Zeolite catalyst is an important means to improve the output and quality in the process of energy processing, and has become a research hotspot in this field. From natural zeolites to artificial zeolites, from three-dimensional (3D) zeolites to two-dimensional (2D) zeolites, with the further study of zeolites, their properties and structures are gradually clear, and they are widely used in catalysis, adsorption, separation and other industries. Especially the 2D zeolites with unique crystal structure (or morphology), their lamellar structures not only reduce the molecular transmission path, but also provide more active sites for the catalytic reaction system and reduce the carbon deposition rate, which have great application potential in the future. When it comes to 2D zeolites, structure directing agent plays a very important role, the types of 2D zeolites can be broadened by changing the structure of directing agent structure, and in this way, the structural change elasticity of zeolites can be increased, which meets the industrial requirements and has a wide range of adaptability. Here, this paper summarizes the development process of 3D and 2D molecular sieves, focuses on the catalytic efficiency of zeolites, expounds their structure-activity relationship in different fields such as coal tar catalytic conversion, C1 chemical industry and biomass catalytic conversion, as well as the preparation path of 2D zeolites, summarizes the conversion mechanism, and analyzes the advantages of 2D zeolites in specific surface area and active site accessibility, it provides a reference for the application of 2D zeolite molecular sieves in industry.

Bacterial infection and resistance have threatened public health and it is necessary to develop a novel and efficient antibacterial agent. Metal-organic frameworks (MOFs) have been widely studied and applied in the antibacterial field. The porous carbon frameworks could provide intrinsic conditions to avoid the agglomeration and avail the stabilization of metal nanoparticles, which may be some synergies. Herein, a novel kind of AgNPs@ZIF-67 composite nanoparticles was prepared by a green, rapid, and cost-effective method, during which zeolitic imidazolate framework-67 (ZIF-67) acted as a template and small silver nanoparticles (AgNPs) could be facilely prepared in situ by the reduction of silver ions with fresh sodium borohydride (NaBH₄). Specifically, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images confirmed the existence of as-prepared AgNPs with average diameters of (7.05±0.09) nm and the introduction of AgNPs did not alter the size and rhombic dodecahedron-type morphology of ZIF-67. Energy-dispersive X-ray spectroscopy (EDS) elemental mapping revealed that AgNPs@ZIF-67 mainly contained uniformly dispersed C, N, O, Co and Ag elements. And the loading ratio of Ag weight content was 0.98% in it. The X-ray diffraction (XRD) pattern of the AgNPs@ZIF-67 sample showed a series of typical and sharp diffraction peaks in the (011), (002), (112), and (222) planes but no obvious peaks attributed to the AgNPs, which exhibited the formation of phase-pure ZIF-67 and well-dispersed of metallic Ag in ZIF-67. Zeta potentials showed a higher potential of ZIF-67 (+25.6 mV) than AgNPs@ZIF-67 (+17.7 mV), indicating the load of negative charged AgNPs and good stability of the as-obtained AgNPs@ZIF-67. Furthermore, Staphylococcus aureus (S. aureus) (ATCC 6538) was used in the antibacterial assay and the bacterial concentration was regarded as 1×10⁸ CFU• mL^–1 when the OD₆₀₀ value of the suspensions was 0.1. The in vitro minimum inhibitory concentration (MIC) of AgNPs@ZIF-67, ZIF-67 were 300, 350 µg•mL^–1, respectively. The antibacterial efficiency of AgNPs@ZIF-67, ZIF-67, and AgNPs at 24 h were 99.889%, 57.192%, and 26.433%, respectively. It was illustrated that the decoration of AgNPs could significantly improve the antibacterial ability of ZIF-67 nanomaterials. Moreover, SEM images of S. aureus showed that AgNPs@ZIF-67 did more serious damage to the cell membrane than ZIF-67. This work provided a facile method to fabricate the AgNPs@ZIF-67 composite nanoparticles, which was demonstrated as a promising antibacterial material based on the synergistic effect of AgNPs and ZIF-67.

The concept of porous liquids (PLs) was initially proposed and divided into three types in 2007 by James, which combine the merits of porous solids and flowing liquids. Recently, PLs have made great progress in preparations and applications. However, challenges for PLs still present to be addressed including their high density, viscosity melting temperatures, and materials cost, which severely limit their large-scale applications in flowing systems. Therefore, it is urgent to look for ideal sterically hindered solutions to construct PLs materials. Notably, the unique properties of ionic liquids (ILs), such as the tunable physicochemical properties for task-specific applications, economic, low regeneration energy requirements, enable them as promising candidates for constructing novel porous ionic liquids (PILs). Over the past five years, PILs based on ILs and existing advanced porous solids, such as porous organic cages (POCs), metal-organic frameworks (MOFs), porous carbons, zeolites, porous polymers, etc., have successively witnessed the achievement in synthesis strategies and applications. Notably, PILs exhibit remarkable properties including permanent porosity, negligible volatility, high thermal/chemical stability, non-corrosivity, adjustable melting temperature, viscosity, high gas solubilities, and fast gas diffusion, which have accelerated their applications in gas adsorption/separation, chiral separation, catalytic conversion, extraction, molecular separations, and other fields. In this review, we summarized recent research progress on the synthesis strategies, properties, and applications of PILs. In the end, challenges and future developments for PILs are summarized and prospected.

11-Chloro-1,1'-di-n-propyl-3,3,3',3'-tetramethyl-10,12-trimethyleneindatricarbocyanine iodide (IR-780) is a near infrared (NIR) photosensitizer for cancer treatment. Under NIR irradiation, IR-780 efficiently generates singlet oxygen or other reactive oxygen species (ROS) in lesion position that ultimately cause cell apoptosis and necrosis. However, biomedical application of IR-780 was limited by its poor water solubility. In this work, we designed a water-soluble IR-780 polymer (Poly-IR) for mitochondria-targeted photodynamic therapy via condensation polymerization. The results of dynamic light scattering (DLS) and transmission electron microscope (TEM) displayed that Poly-IR was self-assembled into nanoparticles in water. And ROS detection experiments demonstrated that Poly-IR quickly and efficiently generated ROS under NIR irradiation in solution and cells. The cellular distribution of the Poly-IR was monitored by confocal laser scanning microscopy (CLSM). Colocalization experiments with mitochondrial stain revealed a high degree of colocalization between Poly-IR and mitochondria, which illustrated that Poly-IR selectively accumulated in mitochondria. Furthermore, we explored the photodamages of Poly-IR to mitochondria through monitoring the change of mitochondrial membrane potential that was stained by JC-1 probe. In the dark, red fluorescence emerged with Poly-IR treated A549 cells. Under NIR irradiation, the red fluorescence was disappeared and green fluorescence was generated in Poly-IR treated cells, which confirmed the photodamage of Poly-IR to mitochondria. The cytotoxicity of Poly-IR was measured by MTT assay (MTT=3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide). The IC₅₀ values of Poly-IR for A549 cells and MCF-7 cells were 9.13 and 10.98 μg/mL respectively in the dark. At the same time, the IC₅₀ values of Poly-IR for A549 cells and MCF-7 cells were 4.57 and 0.22 μg/mL respectively under NIR irradiation. The cytotoxicity of Poly-IR for MCF-7 cells treated with NIR exposure was significantly increased 50 times compared to without irradiation. Live/dead cell staining experiments also verified that Poly-IR had more phototoxicity. Meanwhile, cytotoxicity on tumor cells was also detected by flow cytometry apoptosis assay according to the typical Annexin V-fluorescein isothiocyanate (FITC) and propidium iodide (PI) double staining principle. These results suggested that Poly-IR promoted tumor cells apoptosis under near-IR irradiation, which expanded ideas in mi-tochondria-targeted photodynamic therapy in cancer treatment.

The development of high-efficiency, green and energy-saving material separation and purification technology is of great significance, and gas separation has a wide range of applications in the fields of industry, energy, medical treatment and technology. Since traditional polymer membranes still face many challenges in achieving high-efficient gas separation, the development of new separation membrane materials has become the current hotspot and difficult issue. As an emerging porous coordination polymer, metal-organic frameworks (MOFs) materials have attracted great attention due to their unique, designable topological structures and tunable functionalities. In order to overcome the problem that bulk or powder MOFs are difficult to be used for gas separation efficiently, it is of great significance and a challenging task to develop MOFs membranes for separation. As a representative MOF material, MOF HKUST-1 is widely used to prepare membranes for gas separation due to its advantages of high stability, economic raw material and hierarchical pore structure. The preparation methods and gas separation performances of the HKUST-1 membrane in the past ten years are summarized, and some viewpoints and the research prospect on this research area are described.

Solution small-angle scattering (SAS) is a powerful tool for elucidating the structural properties of soft matter systems. SAS includes X-ray scattering (SAXS) and Neutron scattering (SANS) techniques which allow determination of the material’s properties at a scale ranging from few Angstroms to hundreds of nanometers. Wide time scales ranging from real time (milliseconds) to several minutes can be also covered by these techniques. In recent years, solution SAS techniques have had versatile applications in several research fields, especially in structural biology and in probing self-assembling nanomaterials. Probing the structure of materials at micro- and nano-scales provide an insight on the macroscopic properties of the material. The high throughput and fast time resolution offered by SAXS in combination with the neutron penetrating ability in SANS can offer a great potential to cover different soft-matter systems and processes (i.e. probing the kinetic of self-assembly). Here we review the solution SAS (both synchrotrons and Neutron Sources) capabilities which have been established in mainland China, and cover scattering theoretical developments. Recent advances in solutions SAS used in soft matter will also be discussed. Given the potential offered by the next generation X-ray and Neutron sources, further developments in this field are expected, with a proliferation of solution SAS applications.

Photocatalytic water splitting to produce hydrogen is one of the most promising technologies to solve energy and environmental problems and realize the effective conversion and storage of solar energy. And the development of it has attracted more and more attention with the proposed target of peaking carbon dioxide emissions before 2030 and achieving carbon neutrality before 2060. After decades of unremitting efforts, this “Holy Grail” reaction has made many important research progresses. This article will review the basic concepts, activity test methods and precautions, types of photocatalytic reactions and means of measurement for efficiency. The development of photocatalytic materials including inorganic semiconductor including oxide, (oxy)nitride, sulfur oxides, oxyhalide, sulfide and solid solutions, sensitized photocatalytic materials, polymer, metal-organic framework materials, etc. are introduced. The important research progresses from the perspective of basic processes and key scientific issues such as light absorption, photo-generated charge separation and surface catalytic reaction of photocatalytic water splitting to produce hydrogen are summarized. The strategies for improving the charge separation such as construction of heterojunction, and the reduction/oxidation cocatalyst for promoting the surface catalysis are introduced. The research progress of hydrogen production by photocatalytic overall water splitting (OWS) using one-step or two-steps photo-excitation system is also summarized in details. For the one-step system, the different materials and the strategies of realizing OWS are introduced. Moreover, for two-step system, the types of electron transfer medium, the exploration of materials and the inhibition of competing reaction are mainly discussed. Finally, the challenges and potential development directions of photocatalytic water splitting to produce hydrogen are analyzed and prospected. It is hoped that through the brief introduction of this review, young scientific and technical personnel who have just been engaged in this research will have a clear understanding of some basic concepts, operating specifications, research progresses and current status in the field of photocatalytic water splitting.

Photonic synapse transistors have attracted growing attention due to their salient advantages in information transmission/processing and good potentials for analog neural computing. Currently, most synapse transistors are rigid devices with the limitations in flexible and highly photosensitive semiconductor channel layers. To achieve high-performance flexible photonic synapse transistors, it is essential to develop stimuli-responsive organic semiconductor thin-films to broaden the photo-response range of devices and accelerate separation of photoinduced carriers for improving synaptic performances. Here, poly(3-hexylthiophene) (P3HT) and poly(indacenodithiophene-co-benzothiadiazole) (PIDT-BT) materials with complementary optical absorption have been used to fabricate a bulk composite film of organic semiconductor heterostructures by a solution-processing method. The surface structures and optoelectronic properties of the PIDT-BT:P3HT film and their single component films are studied. By using the PIDT-BT:P3HT heterostructure film as a novel photoactive channel layer, flexible low-voltage photonic synapse transistors have been designed and fabricated with the combination of polyelectrolyte-based dielectrics. The effects of different optical stimulation conditions on the performance of synapse transistors are investigated with insightful discussion on the semiconductor mechanisms. The flexible synapse transistors based on the PIDT-BT:P3HT film exhibit higher excitatory postsynaptic currents than devices with the single component semiconductor layers at the same optical stimulation. The synaptic response of the PIDT-BT:P3HT-based device is also evaluated under different stimulus variables including the optical spike wavelength, duration and frequency. As results, good synaptic characteristics are observed including the high excitatory postsynaptic current, paired-pulse facilitation, and frequency-dependent properties with the tunable synaptic plasticity. It is found that the response in excitatory postsynaptic current of the synaptic device stimulated by two beams (520 nm green laser and 685 nm red laser) together is greater than the sum of the responses stimulated by each beam alone. These results are useful for the design of high-performance photoresponsive semiconductor films and photonic synapse transistors, which are conducive to the development of low-power flexible optoelectronic devices, artificial synapses and beyond.

Organic semiconductor optoelectronic devices have made rapid development and progress in both research and industrial applications. The related directions have become a mature and emerging field. However, the organic materials in such devices usually are extremely sensitive to water vapor or oxygen existed in ambient air, which seriously affects the long-term stability of the devices. In addition to interface engineering, selecting appropriate charge (holes or electrons) transport layers and interfacial materials to improve the water and oxygen tolerance of the device and packing the device with robust encapsulation are all effective strategies to isolate the device from the water and oxygen in ambient air. Among various encapsulation technologies, atomic layer deposition (ALD) is an almost perfect encapsulation approach, which could deposit thin films in the layer-by-layer growth mode at low-temperature, with the characteristics of accurate and controllable thickness, high repeatability, excellent uniformity and high density. These characteristics make ALD to be widely used in semiconductor industry. Here, we review the progress of the applications of the ALD encapsulation techniques in organic light emitting diode (OLED) and provide further discussions on the enlightening significance of ALD encapsulation techniques in organic photovoltaics (OPV) and perovskite solar cell (PSC) encapsulations.

Pd single site catalysts (Pd SSCs) are recognized to be efficient for CO esterification to a valuable product, dimethyl carbonate (DMC), but the tendency of reduction to Pd nanoparticles in CO atmosphere under reaction process leads to a reduced selectivity and limits the industrial application. Hence, the development of appropriate supports to stabilize Pd single sites is of great importance. Metal-organic frameworks (MOFs) are expected to become one of the most ideal choices for supporting SSCs due to their large specific surface area, good stability, and ease of modification. Herein, a stable and highly modifiable MOF, UiO-66-NH₂, has been selected as the support. The pyridine-2-formaldehyde is grafted to UiO-66-NH₂ by post-synthetic modification, connecting to the skeleton of UiO-66-NH₂ via amine aldehyde condensation. In this way a pair of adjacent N atom sites are created to jointly chelate Pd(II) species, yielding Pd^II-UiO-66-X%. The Pd SSCs exhibit high DMC selectivity (>98%) in the CO esterification reaction. Moreover, Pd^II-UiO-66-X% shows excellent stability and more than 85% DMC selectivity can be maintained in 70 h continuous test, thanks to the good dispersion and strong interaction of Pd(II) species and the MOF support. As a control, the Pd(II) species is supported on ZrO₂ to give Pd^II/ZrO₂. Obviously, it is difficult for ZrO₂ to disperse Pd(II) species and to strongly interact with them due to the absence of binding groups. As a result, Pd^II/ZrO₂ is rapidly reduced by CO during the reaction, resulting in decreased DMC selectivity. In addition, the signals of key intermediates are detected and the reaction mechanism on Pd^II-UiO-66-X% is proposed based on in-situ diffuse reflectance infrared Fourier transform (in-situ DRIFT) spectra. The successful fabrication of Pd^II-UiO-66-X% with high selectivity and stability provides great opportunity for CO esterification to DMC.

Red emitter is one of the three primary materials for display, which is widely used in full-color display, biosensing and photodynamic therapy due to the advantages of small emission energy, strong penetrating ability and low background fluorescence interference. At present, the main bottlenecks for the development of red emitters are as follows. (1) The narrow energy gaps of red emitters often lead to serious non-radiative transition and low quantum efficiency. (2) The largely conjugated structure of red emitters results in strong π-π stacking for emission quenching. (3) Molecular design requires greater conjugation, which is difficult in molecular synthesis. Red thermally activated delayed fluorescence (TADF) materials, as a new type of red emitters, can use triplet excitons to release fluorescence through reverse intersystem crossing process, which greatly improves the quantum efficiency. Therefore, red TADF materials have become a hot topic in recent years. Because of the structural advantages, quinoxaline and its derivative are promising building blocks for the construction of red TADF emitters. The research progress of the quinoxaline-based red TADF materials in recent years is summarized, the influence of molecular structure on the properties of materials is discussed, and the prospect is also provided.

The production of ammonia using the Haber Bosch process cannot meet the goal of carbon neutral in the future, electrochemical nitrogen reduction reaction (NRR) to synthesize ammonia contains many advantages and is widely studied these years. Among them, the indirect lithium-mediated nitrogen reduction (LiNR) to synthesize ammonia, which has been successfully repeated, is considered to be a feasible way to produce ammonia via electrochemical method. Li-N₂ battery is another emerging direction, that reduce N₂ to Li₃N successfully during discharge, while received little attention. This paper, innovatively combining Li-N₂ battery system and LiNR, not only utilizes the discharge reduction reaction to fix N₂, but also co-reacts Li, N₂ and proton source (H₂O here) to produce NH₃. A common discharge and charge reaction are included, constituting a complete and clear lithium cycle procedure. During the discharge process, NH₃ generates continuously when N₂ and H₂O are fed together through the gas diffusion layer in the cathode, and the discharge potential in experiment is close to the theoretical value. When the constant current of 100 μA (0.05 mA•cm^-2) is used for 2 h discharge, the ammonia production is 0.67 μg•cm^-2 with Faraday efficiency of 3.2%. A contrast experiment shows that NH₃ generates only when N₂ and H₂O react together. Possible secondary reactions or reasons during discharging and mechanisms for ammonia production during charging are discussed. Lithium can be recycled between cathode and anode, based on Li-N₂ battery, by the recommended procedure, while NH₃ is produced every cycle and goes on. Cyclic ammonia production experiment demonstrates that the yield increases with the number of cycles almost linearly in 3 cycles. Finally, the discharge product LiOH is detected on the cathode inner surface, which proves that the discharge reaction proposed in this paper is valid. For the development of new types of nitrogen fixation methods, this scheme has great research and utilization spaces.

Organic light-emitting transistor (OLET) is a kind of revolutionary miniaturized optoelectronic device which integrates the functions of an organic field-effect transistor and an organic light-emitting diode in a single device. This unique integrated architecture of OLET makes it show great potential for studies of fundamental properties of organic materials, applications in fields of novel organic flexible display/lighting technology, organic electrically-pumped lasers as well as on-chip optoelectronic systems. To realize the full potential of these technologies, the development of key materials and optimization of device fabrication techniques including device structures and processing conditions are highly required. Based on the comprehensive study of the development and basic scientific problems in the OLET field, in the past five years, the authors' research group and collaborators carried out systematical exploratory researches with focuses on the development of high mobility emissive organic semiconductors and construction of high performance OLETs with line- and area-feature emission. Up to now, a series of achievements have been obtained. For instance, we developed a series of anthracene- and fluorene-based high mobility emissive organic semiconductors from the origin of molecular design innovation, which overcomes the science bottleneck of impossibility for integrating high charge carrier mobility and strong emission in the same molecule. Furthermore, this molecular design concept also shows a certain feasibility for the development of other small molecular systems and high mobility emissive conjugated polymers. Moreover, with the mind of integrating the advantages of area-emission of vertical OLET and good gate-tunability and stability of planar OLET, we propose a new area-emission planar OLET architecture, which exhibits a large aperture ratio of over 80% due to the arbitrary tunability of device structure. These preliminary experimental researches and results will provide valuable guidelines for future research of OLETs and their related fields.

Organic solar cells (OSCs) are among the most promising photovoltaic technologies to solve energy and environmental problems. To achieve highly efficient OSCs, controlling over electrode interfacial layers is greatly important for improving charge transportation and collection. Here, ternary metal oxide semiconductor films of Mg-doped NiO (NiMgO) have been prepared via a sol-gel method, and further optimized by several post-treatment strategies. The structures, properties and energy levels of different NiMgO films have been investigated to explore the influence of various post-treatment strategies. Incorporating the ternary NiMgO films as a novel type of hole transport layers (HTLs), non-fullerene OSCs have been fabricated based on a promising bulk-heterojunction of PM6:M36. Their photovoltaic performances and mechanisms of device physics are also investigated. When the sol-gel derived NiMgO film without post-treatment is used as an HTL, the OSCs show a relatively low power conversion efficiency (PCE) of 5.90%. By contrast, after simple ultraviolet-ozone (UVO) post-treatment on the NiMgO HTL, the resulted OSCs exhibit greatly enhanced photovoltaic performances, with an increased open-circuit voltage (V_OC) of 0.87 V and an improved PCE of 12.67%. More importantly, a new dual post-treatment combining surface rinse with UVO treatment has been demonstrated to further optimize NiMgO HTLs and improve device performances. The rinse process can remove excess impurities and flatten the surface of NiMgO films as well as increase the transmittance, while the UVO treatment process is beneficial for reducing surface defects of the ternary oxide films. Benefit-ing from such an efficient dual post-treatment on NiMgO HTLs, the OSCs afford a high PCE of 13.17% with a retained V_OC of 0.87 V, an increased short-circuit current density of 23.48 mA•cm^–2, and an improved fill factor of 64.29%. These results provide an effective way for surface post-treatment and property optimization of semiconducting metal oxide films, and contribute to the development of high-performance optoelectronic devices.

Donor-acceptor cyclopropanes as efficient three-carbon synthetic building blocks were widely employed in the synthesis of many natural products and complex drug molecules. However, the ring-opening of aliphatic substituted cyclopropanes, owing to their poor reactivity, usually suffers from the harsh reaction conditions such as strong Lewis acid, large amount of catalyst, high reaction temperature and so on. In this paper, In(NTf₂)₃ was found as a powerful Lewis acid to catalyze the intramolecular nucleophilic ring-opening reaction of donor-acceptor cyclopropane with indole. This reaction could be used to construct the pyrrolo[1,2-a]-indole framework structure in a facile way. This method could be conducted in mild reaction conditions with a broad substrate scope (15 examples), leading to the target products in up to 96% yield. The general procedure is as following: To a dry Schlenk tube in a glove box, was placed In(NTf₂)₃ (0.1 equiv.), 4 Å molecular sieve (50 mg) and a stir bar. The tube was capped and brought out of the glovebox. After connected to argon via a typical Schlenk line system, a solution of 1 (1.0 equiv.) in PhCl (1 mL) was added dropwise until the reaction was completed (monitored by thin-layer chromatography). Et₃N was added to quench the reaction and the reaction mixture was filtered through a thin layer of silica gel and eluted with EtOAc (100 mL). After removal of the volatiles under reduced pressure, the residue was purified by flash chromatography over silica gel to afford the product. When indole substrate contains electron-withdrawing substituents, the reaction temperature needs to be increased to 100 ℃ to obtain the target product.

The development of modern society highly depends on polymer materials. However, progressive usage and accumulation of polymer products caused the waste of resources and severe environmental issues. To address the abovementioned problem, the development of chemical recycling polymers that could transform the polymers back to monomers and repolymerize to produce polymer materials without value loss is an attractive and important strategy. In recent years, significant advances in the design of “ideal monomers” have enabled the regulation of “polymerization-depolymerization” equilibrium and achieved the closed-loop recycling under mild conditions. This review will focus on the closed-loop recycling of polyesters, polycarbonates, sulfur-containing polymers, and poly(cyclic olefin)s, illustrate the challenges of this field, and provide a perspective on the future development direction.

In this work, a hierarchical screening strategy by synergizing machine learning (ML) and molecular simulation was proposed to identify the optimal adsorbents for CH₄/H₂ separation from 134185 hypothetical metal-organic frameworks (MOFs). At the initial screening, MOF materials with inappropriate pore size and/or volumetric surface area were removed from the total database, resulting in a list of 62278 MOFs. Among them, 10% MOFs were randomly chosen and grand canonical Monte Carlo (GCMC) simulations were performed to calculate the adsorption behaviors of CH₄/H₂ mixture in these MOFs under vacuum swing adsorption (VSA) and pressure swing adsorption (PSA) conditions. Following this, structural/ chemical descriptors and corresponding adsorbent performance scores (APS) of the selected MOFs were employed to develop the random forest (RF) models for VSA and PSA processes. Compared with the accuracy of other ML algorithms, covering support vector machine, k-nearest neighbor, decision tree, and artificial neural network, the proposed model exhibits the optimum predictive power. Meanwhile, the hybrid of structural and chemical descriptors, as well as the application of the preliminary screening strategy improve the accuracy of the RF model. Thus, it was used to predict the APS values of the remaining 90% MOFs in the next stage of screening, and the top 1000 candidates were screened out according to the results. GCMC simulations were subsequently carried out on the top candidates to refine the predictions, and then ten MOFs with the best CH₄/H₂ separation performance were obtained under VSA and PSA conditions, respectively. The high performance of the optimal MOFs was verified by comparison with well-studied MOF materials in the literature. Finally, the feature importance of the descriptors was interpreted by the Shapley Additive Explanations. The result reveals the potential for the developed model to transfer between the two operating conditions due to the consistency of the dominant descriptors, which also provides an efficient pathway for rapid screening of promising MOF adsorbents in CH₄/H₂ separation suitable for different operation scenarios.

Commercial Pt/C, with the ideal 4e^- transfer process for oxygen reduction reaction (ORR), is regarded as the optimal cathode catalyst of fuel cells at present. However, as a noble metal element, the high cost and scarcity of Pt seriously restrict the wide application of fuel cells. On account of this, cheap and high-performance non-noble metal catalysts receive extensive research attentions at present. In this work, by using graphene oxide (GO) as the template, we can realize the in-situ growth of Co-based metal organic framework (MOF) (ZIF-67) on the GO surface by means of the abundant oxygen-containing functional groups on GO, forming the ZIF-67/GO layered composite. During the pyrolysis at 700 ℃ in N₂ atmosphere, the graphene can effectively inhibit the agglomeration of Co nanoparticles with the well retained layered morphology, which can be confirmed by scanning electron microscope (SEM) and transmission electron microscopy (TEM). The X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and nitrogen isothermal adsorption tests were used to analyze the components and microstructure of obtained materials. Moreover, the catalytic performances of different material towards ORR have been also measured by cyclic voltammetry (CV) and linear sweep voltammetry (LSV) analysis in alkaline electrolyte with rotating disk electrode (RDE) at different speeds. Thanks to the high dispersion of active sites, abundant pore structures and excellent conductivity of the obtained Co@N-C/rGO composite, it shows excellent ORR performances with an initial potential of 0.96 V and a half-wave potential of 0.83 V, far superior to that of the Co@N-C catalyst obtained by direct pyrolysis of ZIF-67, and even comparable to that of commercial Pt/C catalyst. In addition, the Co@N-C/rGO composite also exhibits good catalytic stability under constant potential for 20000 s and shows favorable methanol tolerance which is better than Pt/C, demonstrating its great potential as an oxygen reduction catalyst for fuel cell applications.

Drugs can be roughly divided into small molecule drugs (naturally extracted or chemically synthesized) and macromolecular drugs (biologics) according to molecular weight. Although small molecule drugs are still the mainstay of drug research and development (R&D) at present, the slow update rate of small molecule libraries has retained their R&D speed, thus highlighting the increasingly important position of macromolecular drugs in the future pharmaceutical market. In addition to macromolecular biologics, chemically synthesized macromolecular drugs prepared by combining small molecule drugs with natural or synthetic macromolecules have received more and more attention in recent years. Due to the unique characteristic of abundant backbone architectures and spatial framework of macromolecules, including their distinctive backbone effect and multivalent effect, as well as aggregation effect and targeting effect produced by molecular assembly, many new possibilities will be introduced into the design of medicinal chemistry. In view of this, this review will briefly introduce macromolecular effects in medicinal chemistry design, with an emphasis on new performances and functions introduced in drug design based on the backbone effects, multivalent effects, aggregation effects, and targeting effects of synthetic macromolecules. We hope this review could promote the development of chemically synthesized macromolecular drugs and provide new horizons for medicinal chemistry design.

The relevance of low-valent iron complexes bearing sulfur-containing ligands with the reactive iron intermediates in enzymatic dinitrogen fixation has stimulated great synthetic efforts toward them. Low-valent iron thiolate complexes have been mostly known for the thiolate-bridged diiron(I) carbonyl compounds. In contrast, isolable mononuclear iron(I) thiolate complexes are exceedingly rare. Herein, we report the synthesis and characterization of a mononuclear iron(I) complex [(IMes)Fe(SAr*)] (1, IMes=1,3-bis(mesityl)imidazole-2-ylidene, Ar*=2,6-(2',4',6'-Prⁱ₃C₆H₂)₂C₆H₃) as well as its catalytic performance in dinitrogen silylation reaction. Complex 1 was synthesized from the reaction of (IMes)₂FeBr with KSAr* in Et₂O in 81% isolated yield. Single-crystal X-ray diffraction studies revealed that the thiolate ligand in 1 is coordinating to the iron center in an σ:η⁶-fashion via the sulfur atom and one of the flanking Prⁱ₃C₆H₂ ring with the Fe—S distance of 0.2228(1) nm and the Fe—C(Trip) distances ranging from 0.2076(2) to 0.2205(2) nm. Zero-field ⁵⁷Fe Mössbauer spectrum at 80 K (δ=0.56 mm•s^-1; ΔE_Q=0.98 mm•s^-1) and X-band electron paramagnetic resonance data (g=[2.20, 2.03, 1.99]) at 103 K of 1 point to its low-spin iron(I) nature (S=1/2). These data are comparable with those of Holland's iron(I) thiolate complex K[(2-S-1,3-(6-F-3-(2,4,6-Prⁱ₃C₆H₂)C₆H₂)₂C₆H₄)Fe] (Nature 2015, 526, 96). Density functional theory studies support the S=1/2 ground spin-state for 1 and reveal that the interaction between the iron atom and the sulfur atom is essentially σ-bonding in character. In addition, π- and δ-type interactions between the iron atom and the η⁶-Prⁱ₃C₆H₂ ring in 1 also exist. Complex 1 can catalyze the reaction of N₂ with KC₈ and Me₃SiCl in Et₂O at room temperature, affording N(SiMe₃)₃ with a turn-over number up to 73 in 24 h and 87 in 48 h. The reaction employing (IMes)₂FeBr as catalyst has a turn-over number up to 73 in 24 h and elongating the reaction time to 48 h does not lead to further increase of the turn-over number. The fine catalytic performance with 1 over (IMes)₂FeBr implies that the thiolate ligand in 1 might render the catalytically active intermediate a relatively long lifetime.

Saving the energy consumption of the industrial separation process provides an effective way to alleviate the global energy shortage issue. Compared with traditional separation technology, membrane separation possesses low energy consumption and high economic benefits. The exploration of high-efficiency membrane materials is the key strategy to elevate membrane separation performance. Conjugated microporous polymer (CMP) membranes exhibit merits such as rigid and permanent micropores, high porosity, adjustable pore structure and pore environment, and good structural stability, which play vibrant role in molecular separation. In this review, we summarized the fabrication methods of CMP membranes with their advantages and challenges; introduced the research progress and mechanism in molecular separation field, including gas separation, organic solvent nanofiltration, ion sieving and chiral separation, over the recent years, which may provide ideas for designing new CMP membranes with high performance for crucial separation processes.

Low-dimensional semiconductors, especially recent emerging two-dimensional halide perovskites, have shown great potential in extensive optoelectronic applications due to their large structural anisotropy, unique quantum well effect and excellent semiconductor properties. Meanwhile, the bulk photovoltaic effect with a highly sensitive angle-resolved photoresponse arising from ferroelectric materials presents a promising approach for highly polarized-sensitive photodetection. Despite the blooming development of two-dimensional halide perovskite ferroelectric materials, it is a great challenge to grow bulk single crystals of two-dimensional halide perovskite ferroelectric, which restricts their further applications in polarized-sensitive optoelectronic devices. This work mainly focuses on the developing of low-dimensional halide perovskite ferroelectric crystals with excellent photoelectric response. Two-dimensional (2D) halide perovskite ferroelectric (iPA)₂EA₂Pb₃I₁₀ (iPA=isopentammonium, EA=ethylammonium) was synthesized by a solution method through the reaction of stoichiometric lead acetate, isoamine and ethylamine in concentrated aqueous hydroiodic acid. Meanwhile, high quality centimeter-size single crystals of ferroelectric (iPA)₂EA₂Pb₃I₁₀ with the max dimensions up to 15 mm×15 mm×3 mm have been grown via temperature cooling method. On the basis of grown bulk single crystals, further investigations on the crystal structure, optical properties measurements and electrical properties characterization were carried out. The photoelectric response performance and polarization photodetection performance of photoelectric detectors based on the compound ferroelectric single crystal assembly. The result indicated that the unique two-dimensional perovskite structure endows (iPA)₂EA₂Pb₃I₁₀ with strong optical anistropy, narrow bandgap (1.80 eV) and fascinating photoelectric features (on/off ratio=10³). Strikingly, the fabricated photodetectors based on ferroelectric crystal (iPA)₂EA₂Pb₃I₁₀ manifest excellent photoelectric features, including large dichroism ratio (2.3), high responsibility (193 mA•W^–1) and photodetectivity (7.0×10¹¹ Jones), better than most photodetector based on intrinsic optical anisotropy of 2D materials. This work will be of great significance to lay a foundation for the exploring of multifunctional halide perovskites and points out the direction for bulk grown of highly anisotropic halide perovskite ferroelectric crystals and promotes their further applications in highly polarized-sensitive photodetection.

Dinitrogen gas is highly chemically inert, and the activation and transformation of dinitrogen are challenging. Nitrogen-containing organic compounds have extensive and important applications in developing the national economy. It is of great scientific and economic significance to realize the direct conversion from dinitrogen to nitrogen-containing organic compounds under mild conditions. The activation and transformation of dinitrogen via metal-nitrogen complexes are one of the research hotspots, and chemists have made significant achievements in this field during the past decades. The current research on the activation and transformation of dinitrogen mainly focuses on the main group and transition metal complexes. In contrast, the research on rare earth (RE) and actinide (An) metal-nitrogen complexes is relatively less. Although nearly one hundred crystal structures of rare earth and actinide metal-dinitrogen complexes have been reported, the vast majority of them cannot undergo further nitrogen derivatization reactions, and the types of the supporting ligands are still limited. However, due to the unique electronic structures, f-block complexes can exhibit unusual reactivity different from the main group and transition metals. For example, the f-block metals do not necessarily have to stay in a low oxidation state to activate the dinitrogen, which may lead to the discovery of new dinitrogen transformation modes. As China is rich in rare earth and thorium resources, it is vital to carry out research on dinitrogen fixation and transformation based on rare earth metals and actinides. The synthesis of rare earth and actinide dinitrogen complexes over the past five years, as well as the progress on the generation of nitrogen-containing organic compounds from dinitrogen gas promoted by rare earth and actinide complexes were summarized in this review.

The Ni-rich layered cathode material LiNi_0.8Co_0.1Mn_0.1O₂ presents a high specific capacity and relatively low cost, however, the inherent structure instability during the electrochemical cycling process hinders its application widely. Universally, the strategy of surface coating can be used to improve the structural stability of the material and then improve its electrochemical performance. This work combines the high-speed solid-phase coating method and the high-temperature sintering method to coat the electronic conductor antimony tin oxide and lithium-ion conductor lithium metaphosphate on the surface of the LiNi_0.8Co_0.1Mn_0.1O₂ material, respectively. The electron/ion conductor double coating layer forms a charge conversion and transport channel on the surface of the LiNi_0.8Co_0.1Mn_0.1O₂. The electronic conductivity of the double-coated LiNi_0.8Co_0.1Mn_0.1O₂ material increased from 2.17×10^-3 Ѕ•cm^-1 to 1.02×10^-2 Ѕ•cm^-1, and the diffusion coefficient of lithium-ion also increased from 7.05×10^-9 cm²•s^-1 to 2.88×10^-8 cm²•s^-1. At the same time, due to strong P—O bonds and stable metal oxides, the double-coating layer on the surface of the LiNi_0.8Co_0.1Mn_0.1O₂ material can effectively restrain the irreversible phase transitions, and it also can inhibit the interfacial reactions under high electrode potential. The electrochemical performance test demonstrated that the cyclability and rate performance of LiNi_0.8Co_0.1Mn_0.1O₂ material improved due to surface modification. The cathode assembled with double-coated LiNi_0.8Co_0.1Mn_0.1O₂ material can maintain a reversible capacity of 161.1 mAh•g^-1 after 150 cycles at 1 C (after being activated at 0.1 C for two cycles, 1 C=180 mA•g^-1) during 2.7~4.3 V (vs. Li/Li⁺), with a capacity retention of 87.1%. This coated LiNi_0.8Co_0.1Mn_0.1O₂ material also displays a specific capacity as high as 133 mAh•g^-1 at 10 C. In comparison, the pristine LiNi_0.8Co_0.1Mn_0.1O₂ delivers a capacity of only 113 mAh•g^-1 after 100 cycles and a reversible capacity retention rate of less than 60% (a decay rate of 0.4% per cycle).

The pursuit of unusual bonding environments of carbon species with non-octet electronic configurations has been quite active in fundamental organic and theoretical chemistry for many decades. In this respect, a distinct carbone species has been successfully isolated recently and defined as “carbodicarbene” or “bent allene.” Carbone is an important active intermediate since the synthesis of radical, carbene and carbyne. This neutral two-coordinated central carbon atom possesses two sets of lone pair electrons, possessing strong coordination ability. The present review introduces the discovery, fundamental properties and coordination chemistry of carbone. Meanwhile, the application of its relevant complexes in catalysis is introduced.

Chiral organic semiconductors have stimulated extensive research interests in the field of organic optoelectronics due to their fascinating properties. The incorporation of chirality into organic semiconducting materials can not only control their aggregation states by virtue of the unique non-covalent interactions among chiral molecules to regulate electronic/ optoelectronic properties, but also facilitates the emergence and development of circularly polarized light direct luminescence and detection. The interactions between chiral materials and circularly polarized light allow them to show broad application prospects in the field of three-dimensional display, quantum communications, information storage and processing, and so forth. This review summarizes the research progress of chiral organic optoelectronic materials and devices in recent years. It mainly reviews the influence of chirality on material properties and device performance, focusing on the applications of circularly polarized light luminescence and detection using chiral organic semiconductors, and aiming to promote the development of relevant research in the field of chiral optoelectronics.

Magnesium hydride is a promising hydrogen storage material due to its high hydrogen storage capacity, low cost and abundance. The gravimetric and volumetric hydrogen capacities of MgH₂ are about 7.6% and 110 g/L, respectively. However, its sluggish de/re-hydrogenation rates and high operating temperatures ranging between 300~400 ℃ restrict it in practical applications. Catalyzing has been proved to be an effective method to improve its hydrogen storage performance. In this work, V₂O₅ has been chosen as a catalyst for improving the de/re-hydrogenation kinetics of MgH₂. Experimental results show that MgH₂ doping with V₂O₅ (w=5%) has the best hydrogen storage properties among the doping amounts (w) of 2.5% to 10%. Comparing with the pristine MgH₂, the addition of V₂O₅ (w=5%) significantly improves the ab/desorption behaviors of MgH₂. V₂O₅ (w=5%) doped MgH₂ starts releasing hydrogen from 175 ℃ which is 89 ℃ lower than the additive-free as-milled MgH₂. It should be noted that the dehydrogenated V₂O₅ (w=5%) doped MgH₂, is able to absorb 2.1% and 3.8% in the mass fraction of H₂ respectivity, within 30 and 180 min at room temperature and 3 MPa hydrogen pressure. Under the same hydrogen pressure, when the temperature is increased to 300 ℃, the mass fraction of H₂ absorbed by the sample is as high as 6.7% within 1 min. In addition, the catalyzed system shows a good reversibility, after 20 cycles, the hydrogen capacity maintains above 6.0%. Compared with the pure MgH₂, the dehydrogenation apparent activation energy of V₂O₅ catalyzed sample decreased from 108 to 56 kJ•mol^–1. X-Ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) have been employed to investigate its reaction mechanism. It shows that the formation of metallic vanadium and low-oxidation vanadium during ball milling and dehydrogenation process play important roles in improving the de/re-hydrogenation kinetics of MgH₂/Mg system.

Boiling point (BP) is the basic physical chemistry quantity of organic molecular liquids, and an important parameter in the chemical industry. The boiling point of organic molecules is determined by the molecular structure, showing a complex structure-property relationship. Traditional methods such as function method and group contribution method cannot cope with the prediction of BP of organic molecules of complex and diverse structures. In this study, we developed an ensemble machine learning method, combining artificial neural networks (ANN) and support vector machines (SVM), to build a multi-component model to realize the boiling point prediction of high accuracy in wide structure space. We developed three heterogeneous models: ANN based on interpretable descriptors, ANN based on correlated descriptors, and SVM based on hybrid molecular fingerprints. The three heterogeneous models were evaluated and optimized using a boiling points data set containing 4550 organic molecules of various categories. The first model (Model A) is an interpretable ANN with selected descriptors possessing physical properties such as molecular composition and molecular chain branches, and with an ANN structure of 19-14-1. The second model (Model B) is an ANN with 35-30-1 structure, of which the descriptors were obtained by using correlation coefficient selecting and bidirectional stepwise regression method. The third model (Model C) is a fingerprint SVM, which had integrated molecular fingerprint information of 1679 bit. Among the three component models, Model A had the best generalization ability and Model B had the best prediction accuracy. The heterogeneous multi-component learner combined with the three models showed a better prediction accuracy and generalization property with low overfitting than that of a single model or homogeneous model. The mean square error on test set of the multi-component model is 12 K by a 5-fold cross validation on 4550 organic molecular data sets, better than all the previous BP prediction methods. The ensemble machine learning strategy we developed here based on heterogeneous models can also be well generalized to the prediction of physical chemical properties beyond BP.

The global pandemic of COVID-19 has caused serious harm to people’s healthy life and the normal operation of society. People have paid more attention to the prevention and control of microbial contamination such as bacteria and viruses. Blocking the spread of disease-causing microorganisms through indirect contact with humans through contaminated surfaces, or avoiding direct contact with them, is the primary way to protect us from harm. Current solutions include designing antibacterial and antiviral surface coatings and developing personal protective equipment made from self-cleaning films or fabrics. In this paper, the work of several widely studied metals, metal oxides, metal organic framework materials, etc. with antibacterial and antiviral functionality is reviewed, their microbial inactivation mechanisms as well as performance are summarized and discussed. In the end, the future perspectives on emerging research directions and challenges in the development of antibacterial and antiviral coatings and films are presented.

Arylstannanes are highly valuable synthetic intermediates in constructing aryl carbon-carbon bonds and carbon-heteroatom bonds in functional molecules. These compounds have demonstrated great applications in medicinal chemistry, materials science and organic synthesis. Due to the synthetic value, development of efficient and novel methods to synthesize arylstannanes is of significant importance. According to the type of reaction mechanism, this content will illustrate the methods for synthesizing arylstannanes in recent years including (1) stannylation of aromatic nucleophiles; (2) stannylation of aromatic electrophiles; (3) transition-metal-catalyzed stannylation coupling reactions; (4) stannylation reactions mediated by aryl radical intermediates; (5) cyclization of alkynes and tandem stannylation. Finally, we further provide a perspective on the development direction of the synthesis of arylstannanes.

Metallized polymer materials have been widely applied in the fields of communications, electronics and aerospace. Electroless copper plating is one of the important techniques for surface metallization of polymer materials. The pretreatments of polymer surface can directly affect the adhesion and levelness of the electroless copper coating. In this paper, we introduce in detail the kinds, compositions and properties of non-conductive polymer materials, and review the research progresses of the pretreatments for electroless copper plating on the non-conductive polymer materials’ surfaces.

Indole skeletons are widely used in drug research and development as a “privileged structure”, while spirocyclic scaffold as a common structural unit, usually plays an important role in the bioactivity and physicochemical properties of molecule skeletons. Hence, spiroindoles which incorporate both indole and spirocycle units have great significance and widespread applications in pharmaceutical field, and substantial progress has been made in the field for their construction and modification. C—H Activation via directing group's assistance has emerged as a powerful approach in the field of organic synthesis. To date, various 2- and 3-indolyl-tethered aza-spiro-centres via C—H activation have been successfully achieved. However, due to the inherent reactivity of the pyrrole side of the indole, introduction of spiro-containing systems onto the benzenoid core of indole still remains challenging. Here, by installing an appropriate directing group onto the C(3) position of indole, a mild and efficient method of Rh(III)-catalyzed selectively C(4)—H activation/cyclization of indole with diazo compound was developed. As a result, a series of novel aza-spiro[4,5]indole derivatives were obtained in mild to excellent yields. The protocol showed excellent functional group tolerance. Gram-scale synthesis demonstrated the utility of this protocol, and further modification via click chemistry offered the novel scaffold as a versatile spiro linker. A general procedure for the synthesis of spiroindole derivatives is described as the following: to a solution of N-(pivaloyloxy)-indole- 3-carboxamide (0.1 mmol), [Cp*RhCl₂]₂ (1.6 mg, 2.5 mol%) and NaOAc (1.6 mg, 20 mol%) in CH₃CN (1 mL) was added diazooxindole (0.12 mmol) under air. Then the reaction mixture was stirred at room temperature for 12 h. After completion of the reaction, the resulting mixture was diluted with 25 mL of EtOAc, and filtered through a celite pad. Then the filtrate was concentrated under vacuum to give the crude product, which was purified via silica gel to obtain the corresponding spiroindole product.

Organogermanium compounds have been gaining more attention for their unique properties compared to silicon or tin. Among which, tetraalkylgermanes, especially alkyltrimethylgermanes that have been confirmed to be active in photoredox radical reactions, are still lack of efficient and simple synthesis methods. Herein, we report a new protocol using commercially available trimethylgermanium bromide and alkyl bromides as substrates and cheap copper(II) sulfate as catalyst. When using magnesium powder as the reductant, a series of alkyltrimethylgermanes could be generated in moderate to good yield. Mechanism studies suggested a probable in-situ Grignard reaction pathway. The copper salt added could significantly accelerate the reaction between organohalogermanes and Grignard reagents so that the formation of Ge-Ge byproduct from the reduction of organohalogermanes by magnesium could be inhibited. Compared to the traditional method using Grignard reagent and organohalogermanes, this new protocol has better compatibility towards functional groups like esters and amides. The protocol could also be expanded to the synthesis of various tetraalkylgermanes or germacycloalkanes using dichlorodimethylgermane and alkyl bromides. General procedure for the synthesis of alkyltrimethylgermane is: To an oven-dried 25 mL screw-capped tube equipped with a stir bar was charge with 48 mg (2 mmol) magnesium powder and 8.0 mg (0.05 mmol) CuSO₄. The tube was vacuumed and backfilled with argon for three cycles. 6 mL freshly distilled THF was added followed by the addition of 128 μL (1 mmol) trimethylgermanium bromide and 1.5 mmol alkyl bromide. The mixture was sealed with a Teflon stopper, warmed to 60 ℃ and stirred for 10 h. After cooled to room temperature, the resulted mixture was quenched with saturated NH₄Cl solution, extracted with diethyl ether and washed with brine. Combined organic layer was dried over Na₂SO₄ and concentrated under reduced pressure. The residue was purified by flash column chromatography on silica gel or distillation to give the desired alkyltrimethylgermane.