Hole transport layer plays an important role in extracting and transporting photogenerated holes from the perovskite layer and suppressing back electron in Perovskite solar cell (PSC). It is an important component of high-performance devices. Classic hole transport materials, such as 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (spiro- OMeTAD), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), etc., have high prices and low hole mobility, which limit the large-scale application. In recent years, self-assembled monolayers (SAM) have been widely used as hole transport layers in inverted PSC to improve device performance. SAM molecular structure contains anchoring functional groups, which can form a single molecule film on the substrate. It has the advantages of low material consumption, no need for additives, low parasitic absorption, compatibility with tandem devices, and is conducive to large-scale manufacturing. It has become a research hotspot in the field of perovskite solar cells. In the light of the development of PSC, this review classifies and summarizes the recent studies on SAM-based hole transport layers according to the different anchoring groups in the SAM molecular structure, and analyzes the effects of the molecular structure changes on the molecular properties and device performance. Finally, the development of SAM as a hole transport layer is summarized and prospected.

Due to the unique properties of fluorine atom(s), the introduction of fluorinated functional groups into molecules has become one of the powerful strategies in the discovery of new pharmaceuticals, agrochemicals, and advanced functional materials. Consequently, considerable efforts have been made to develop new and efficient methods for preparing organofluorine compounds. Among the fluorine functionalities, the gem-difluoroallyl group represents one of the attractive moieties due to the unique properties of the difluoromethylene group (CF₂) and the synthetic versatility of the carbon-carbon double bond. Over the past decade, important progress has been made in the catalytic gem-difluoroallylation reactions. However, the efficient methods for the preparation of gem-difluoroallyl arenes remain limited despite their important applications in medicinal chemistry. Here, we report a palladium-catalyzed gem-difluoroallylation of heteroaryl bromides with gem-difluoroallylboronates. The reaction proceeds under mild conditions with high efficiency, high functional group tolerance, and excellent regioselectivity. A series of heteroaryl bromides are applicable to the reaction, providing facile access to gem-difluoroallyl heteroarenes of medicinal interest. A representative procedure for the palladium-catalyzed cross-coupling of heteroaryl bromides with gem-difluoroallylborons is as following: heteroaryl bromide (0.40 mmol, 1.0 equiv.) and (P(t-Bu)₂Ph)₂•PdCl₂ (3.0 mol%) were added to a 25 mL of Schlenck tube. The tube was then evacuated and backfilled with Ar (3 times). CsF (2.0 equiv.), gem-difluoroallylboron (0.44 mmol, 1.1 equiv.), and 1,4-dioxane (2.0 mL) were added under Ar. The tube was screw capped and put into a preheated oil bath (100 ℃). After stirring for 2 h, the reaction mixture was cooled to room temperature and diluted with ethyl acetate (2.0 mL). The yield was determined by ¹⁹F NMR using fluorobenzene (1.0 equiv.) as an internal standard before working up. If necessary, the reaction mixture was diluted with EtOAc and filtered with a pad of cellite. The filtrate was concentrated, and the residue was purified with silica gel chromatography to give product 11.

Elemental halogen, that is fluorine (F₂), chlorine (Cl₂), bromine (Br₂) and iodine (I₂), plays an important role in the chemical industry. However, the toxicity, corrosiveness and volatility of elemental halogen pose serious challenges for their safe storage and transportation. Thus, the precuring of these elemental halogen can effectively improve the safety of their usage. Ideal precuring materials for elemental halogen need to meet a variety of requirements, such as stability, selectivity, recyclability, processability, etc., which brings great challenges to the design and synthesis of desired materials. So far, some precuring materials for Cl₂ and Br₂ have been reported (F₂ is not available yet). The summary and review of these materials will help to provide reference for the follow-up materials optimization and design. However, as far as we know, the related review has not been reported yet. Therefore, we give a comprehensive overview of the precuring materials for Cl₂ and Br₂ including porous organic polymers (POPs), metal-organic frameworks (MOFs), porous organic cages (POCs) and metal halides. The corresponding mechanism and structure-property relationship are discussed in detail. The purpose of this paper is to provide a useful insight into the follow-up materials design for the elemental halogen precuring, and finally get an ideal precuring materials with practical application prospects, so as to improve the usage safety of elemental halogen and reduce the risk of halogen leakage. It is of great significance to environmental protection and sustainable development.

Two-dimensional polymers (2DPs) are a type of planar polymer materials that possess regular porous structures. They fulfill the demand for thin, high-performing, and stable materials in flexible devices, making them highly potential candidates for applications in the field of flexible electronics. As a special class of covalent two-dimensional polymer materials, two-dimensional covalent organic frameworks (COFs) refer to crystalline porous materials with a two-dimensional topology formed by connecting π-conjugated building units through covalent bonds. The unique electronic structure of COFs gives them better electrical properties compared to other two-dimensional polymers. Furthermore, their unique periodic porous structure, high specific surface area, and excellent stability make them highly suitable for various applications such as ion transport, optoelectronic materials, and catalysis. Among these, carbon-carbon bond-linked COFs are regarded as one of the most promising types of two-dimensional polymers due to their excellent stability and good crystallinity. In recent years, many carbon-carbon bonded COFs with different structures and excellent properties have emerged based on different design principles and synthesis strategies. In this review, we summarize and introduce four common synthesis methods for preparing C=C bonded COFs, namely solvent-thermal method, melt-polymerization method, interface polymerization method, and copper template method. Furthermore, we categorize C=C bonded COFs into four classes: [C₂+C₃], [C₂+C₂], [C₃+C₃], and [C₄+C₂], according to the topological structure of the building units. We focus on analyzing the relationship between the composite structure of these COFs and their stability, electrical properties, catalytic performance, and other properties. Additionally, we compile and summarize the research progress of C=C bonded COFs in terms of synthesis methods, structural innovation, performance improvement, and practical applications. This compilation will be beneficial for researchers in the subsequent studies of C=C bonded COFs to select building units based on target structure and performance application and conduct pre-design. Furthermore, this review also includes previously overlooked C—C bonded COFs, providing a more comprehensive reference. In summary, this review aims to provide guidance for researchers in related fields to better design and synthesize multifunctional crystalline porous materials, thereby promoting the further development and application of carbon-carbon bond-linked COFs in various fields.

Lithium metal is considered an ideal negative electrode material for its highest theoretical specific capacity and lowest redox potential. However, traditional lithium metal batteries have faced thorny challenges, primarily due to the growth of lithium dendrites and utilization of leaky, flammable organic liquid electrolyte, which would lead to battery failure and potential safety hazards. Replacing liquid electrolyte with solid-state electrolyte comes out to be a promising solution to the issues above. Recently, polymer solid electrolytes have garnered significant attention for their lightweight, safety, designable structure and excellent mechanical properties, which could restrain the uncontrollable growing of lithium dendrites. However, the high crystallinity and the resultant low ion conductivity at room temperature have impeded their widespread commercialization. Significant efforts have been directed towards the development of polymer solid electrolytes with superior performance. Herein, the recent development of polymer solid electrolyte is reviewed and summarized, including polyether polymers, polycarbonate polymers, fluorinated polymers, poly(ionic liquid) polymers, and single ion conductive polymers. Each of these polymer solid electrolytes offers unique advantages and challenges. The respective properties of different polymer electrolytes and the influence on the electrochemical performance are compared and discussed in detail. This article also focuses on the progress in structural designs and the innovation in synthesis process for different polymer matrixes in order to improve the ion conductivity at room temperature. For structural designs, grafting kinds of polar groups to the matrix structure, or designing various types of chain structures can reduce crystallinity, and thus enhance the ion transport. In addition to the conventional solution-casting method and phase inversion technique, electrospinning method, UV coating and other in-situ processes are utilized in the preparation of polymer solid electrolytes. Finally, in this paper, the existing fundamental research challenges and practical application issues associated with polymer solid electrolytes are thoroughly discussed. It is our sincere hope that this review will offer insights and references for the design, synthesis, and development of novel polymer solid electrolytes, which holds significant promise for electrochemical performance enhancement and safe operation of all-solid-state lithium metal batteries.

In 1989, Qing-Yun Chen’s research group at the Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences reported the development of methyl fluorosulfonyldifluoroacetate (FSO₂CF₂CO₂Me or MFSDA) as trifluoromethylation reagent. This reagent is now known as Chen’s reagent, which is perhaps the first well-recognized and widely used trifluoromethylation reagent originate from China. Despite the widespread use of Chen’s reagent in both academia and industry, the detailed mechanism underlying the conversion of Chen’s reagent into a trifluoromethyl source has remained elusive. In this contribution, we conducted a thorough investigation into the reaction mechanism, employing density functional theory (DFT) calculations. Geometry optimizations and frequency analyses were performed using the PBE0/def2-SVP level of theory. To ensure accurate electronic energy calculations, single-point energy calculations were conducted at the ωB97X-D/def2-TZVPP level of theory. The solvent effects were considered using the solvation model density (SMD) model during both geometry optimizations and single-point energy calculations. Furthermore, Gibbs free energies were corrected with GoodVibes, employing Truhlar et al.’s quasi-harmonic treatment by setting all positive frequencies less than 100 to 100 cm^–1. Concentration corrections were applied from 1 atm to 1 mol/L. Our calculations reveal the detailed mechanism governing the generation of copper(I) trifluoromethyl from Chen’s reagent in the presence of a CuI catalyst. An in-depth understanding of such mechanistic details would be helpful for future development of new reaction and application with Chen’s reagent.

To achieve carbon peaking and carbon neutrality goals, increasing the share of non-fossil energy consumption and accelerating the growth of clean, low-carbon and sustainable energy are highly desirable in developing a clean and diversified energy supply system. In this retrospect, new energy vehicles have become an ideal substitute for the traditional fuel vehicles due to their green, low-carbon, clean and sustainable characteristics, and have promising development in the future transportation industry. However, the continuously increasing demand for longer range and safety performance in electric vehicles has challenged the state-of-the-art liquid-state lithium-ion batteries. At present, the conventional lithium-ion batteries based on the traditional carbonate liquid-state electrolyte face many potential safety issues, such as leakage, volatility, combustion and explosion. In addition, their energy density reaches closely to their theoretical upper limit. Therefore, breakthroughs in battery storage technologies are urgently needed. Solid-state lithium-ion batteries, which are built with solid-state electrolytes and Ni-rich cathodes/graphite (or silicon-carbon) electrodes are the most promising battery technologies combining high energy density and improved safety property. An in-depth literature survey shows that considerable progress in the construction of high safety, high energy density Ni-rich cathodes/graphite (or silicon-carbon) solid-state lithium-ion batteries have been achieved recently. Hence, this review mainly summarizes the research progress and the development of Ni-rich cathodes/graphite (or silicon-carbon) solid-state lithium-ion batteries using inorganic solid electrolytes and polymer solid electrolytes. Moreover, the remaining challenges and future development trends of Ni-rich cathodes/graphite (or silicon-carbon) solid-state lithium-ion batteries are also discussed and presented. It is expected that the current review would contribute to the further research and development of Ni-rich cathodes/graphite (or silicon-carbon) solid-state lithium-ion batteries.

In recent decades, the development of traditional energetic materials has encountered a bottleneck. How to continue to improve the energy level and break the bottleneck has become an urgent problem in the field of energetic materials. Fluorine is a stronger oxidizing agent than oxygen, and theoretically the introduction of fluorine can further increase energy density. Thirteen kinds of energetic molecules containing (difluoramino)dinitromethyl substituted heteroaromatic rings were designed. To ensure the possibility of synthesis, all the structural designs are based on existing intermediates and could be transformed into target molecules through mature synthesis methodologies. The molecular structure, initial thermal decomposition mechanism and energy characteristics were studied theoretically with density functional theory (DFT) methods (B3LYP/6-311+G(d,p) and M06-2X/6-311+G(d,p)) using Gaussian16 program. By calculating the mechanism of the initial decomposition reaction, the trigger bond was determined to be one of the C—NO₂ bonds in the (difluoramino)dinitromethyl group. Dynamic stability is evaluated by the energy barrier of the trigger bond breaking. The results show that most of these molecules have sufficient dynamic stability, the initial decomposition reaction barriers are around 30 kcal/mol. The relationship between the molecule structure and the dynamic stability is revealed. The carbon radical center in the transition state is connected with the strong electron-withdrawing groups (-NO₂ and -NF₂) and the heterocyclic ring with a certain electron-donating ability. This is a typical “push-pull” electronic structure, which makes the free radical particularly stable. Therefore, the homo-cleavage energy barrier of the trigger bond is determined by the stabilizing effect of heterocyclic rings on the methyl free radicals. The energy properties of these molecules were theoretically evaluated with nitrate ester plasticized polyether (NEPE) solid propellant formulations using EXPLO5 program. The results show that the specific impulse of one dynamic stable molecule is up to 280.1 s, which is about 8.4 s higher than that of the traditional HMX (Octogen) formulations.

Uranium is one of the most important elements in the development of nuclear industry. However, terrestrial uranium resources are limited and difficult to meet the development needs. Since seawater is rich in uranium resources (about 4.5×10⁹ t), which is more than one thousand times of the known terrestrial uranium resources, how to extract uranium resources from seawater has attracted much attention. However, uranium exists in seawater in the stable carbonate of [UO₂(CO₃)₃]^4-, which has a very low concentration of 3.3 μg/L, and the competitive ions especially for vanadium ions and biological contamination are serious obstacles to the extraction of uranium. Because of these complicated conditions of seawater and the extremely low concentration of uranium, uranium extraction from seawater faces many challenges. Many researchers have carried out a lot of studies, and various methods have been developed for the extraction of uranium from seawater. Among them, the adsorption method has been widely used in the extraction of uranium from seawater. This review focuses on the adsorption materials developed in recent years for uranium extraction from seawater, including inorganic materials, organic materials, inorganic-organic hybrid materials, and analyzes their advantages and disadvantages of the materials in terms of their adsorption capacity, selectivity, antimicrobial properties, stability, and recyclability. At the same time, the coordination mechanism of the typical functional groups such as amidoxime and carboxyl groups as well as other representative functional groups reported in recent years toward uranyl cations have been summarized, and the results show that in addition to amidoxime, other functional groups such as pentadentate chelating ligands also have good affinities for uranyl cations. Besides, the future development of uranium extraction materials from seawater is also prospected. This review is expected to improve our current understanding of the interaction mechanism of functional groups toward uranyl cations, and provide references for the development of efficient materials for uranium extraction from seawater.

Coal gangue, a byproduct of coal mining and processing, has long been regarded as solid waste. However, with the increasing severity of resource scarcity and environmental pollution issues, the efficient utilization and resource recovery of coal gangue have become urgent needs. This paper reviews the modification and resource utilization of coal gangue, focusing on its introduction, pretreatment, modification methods, and the latest progress in resource utilization. Firstly, coal gangue is a porous granular material composed mainly of inorganic minerals, organic matter, and water. Due to its complex nature and diverse composition, the direct utilization of coal gangue is somewhat limited. Therefore, modifying coal gangue is a key step in achieving its resource utilization. Pretreatment before modification is a crucial step to ensure the effectiveness of coal gangue modification. This involves physical processes such as crushing, screening, magnetic separation, and washing of coal gangue to reduce particle size, achieve uniformity, enhance surface area and pore structure, thereby providing a solid foundation for subsequent modification. The modification methods of coal gangue mainly include chemical modification, biological modification, and composite modification. Chemical modification involves introducing functional groups or altering its chemical structure through processes such as acid-base treatment, organic modification, thermal activation, etc., thereby improving its adsorption performance, dispersibility, etc. Biological modification utilizes microorganisms, enzymes, and other biological systems to enhance the environmental friendliness and biocompatibility of coal gangue. Composite modification combines the advantages of various modifications to make coal gangue-based materials meet requirements better. Significant progress has been made in the resource utilization of coal gangue. Modified coal gangue is extensively utilized in environmental management sectors like soil remediation and wastewater treatment, showcasing excellent adsorption capabilities and catalytic activity. Furthermore, modified coal gangue is utilized as raw material in sectors such as construction materials, energy recovery, and fertilizer production, providing a new pathway for reducing mineral resource consumption and advancing circular economy development.

Aziridines are among the most important building blocks in modern organic synthesis due to their proclivity to ring-opening with a wide range of nucleophiles. This small nitrogen-containing ring system is a highly strained molecule, and C—N fragmentation allows it to be used as the precursor for various scaffolds (including amino alcohols, amino ethers, and diamines) that are not readily accessible through conventional methods. The driving force for this C—N activation is the release of ring strain. In conclusion, significant advances in this filed have been realized with various of nucleophiles. On the other hand, the use of transition metal for C—N activation is one of the most significant methods for the construction of complex molecules. Transition metal-catalyzed ring opening cross-coupling of aziridines have received much attention in recent years. Over the past decades, many groups have described approaches to engage aziridines as electrophiles in nickel-catalyzed cross-coupling. This paper reviews the recent advances in nickel-catalyzed ring opening cross-coupling of aziridines, focuses on the ring-opening methodology, compares the regioselective of the different aziridines, and summarizes generalities of these strategies. We split this paper into three sections consisting of construction of β-functionalized amines via Ni-catalyzed, dual photoredox/Ni-catalyzed, and Ni-catalyzed electrochemical cross-coupling of aziridines. Traditional methods for the ring-opening of aziridines include (1) nickel-catalyzed S_N2 nucleophilic ring-opening, (2) nucleophilic halide ring-opening, and (3) electro-induced ring-opening.

Post-transcriptional regulations play a critical role in diverse biological processes, and a series of RNA-protein interactions are involved in their underlying mechanism. RNA-binding proteins (RBPs) are key participants and executors in entire life cycle of RNA, affecting the operation of biological processes and the maintenance of cellular homeostasis. The RNA-binding proteome profiling therefore provides crucial information for discovering biological markers and targets of diseases. An array of RBPs capturing methods have been developed in recent years, ranging from profiling binding proteins of specific RNA to unbiased global RBPs identification, and even to exploring the functional aspects of RBPs such as spatial distribution and/or post-translational modifications. This review will focus on tool development for RBP proteomics and functional proteome characterization, and finally discusses bottlenecks and future prospects of this exciting direction of RBP proteomics.

Transition-metal-catalyzed asymmetric dearomatization reaction represents a straightforward method to access chiral cyclic compounds. In recent years, enantioselective dearomative Heck reactions of indoles, benzofurans, pyrroles, furans, and naphthalenes have been successfully developed. Nevertheless, current reports are mainly limited to the intramolecular reaction, the intermolecular asymmetric dearomative Heck reactions are still underdeveloped. In consideration of the relatively mild reaction conditions in oxidative Heck reaction, we envisioned that the intermolecular dearomative oxidative Heck reaction and its asymmetric induction might be possible due to its commonly-proposed cationic rather than neutral mechanism for Heck reaction. In the present work, an enantioselective palladium-catalyzed intermolecular dearomative Heck reaction of indoles with arylboronic acids has been developed. By employing Pd(OAc)₂ as the catalyst precursor, pyridine- oxazoline as the chiral ligand, oxygen as an oxidant, and benzoquinone (BQ) as the co-oxidant, a series of chiral indolines bearing a C2-substituted quaternary stereocenter were afforded in moderate to good yields and moderate ee values. A general procedure for this enantioselective dearomative oxidative Heck reaction is described as the following: To a dried Schlenk tube were charged with Pd(OAc)₂ (4.5 mg, 10 mol%) and ligand L9 (15.1 mg, 20 mol%) under O₂ atmosphere. 2 mL of N-methylpyrrolidone (NMP) solvent was then introduced via a syringe and the Schlenk tube was sealed using a Teflon cap. The mixture was stirred at 60 ℃ for 30 min in order to form the catalyst complex. After cooling to room temperature, indole substrates 1 (0.2 mmol), aryl boronic acids (0.6 mmol), and co-oxidant BQ (4.3 mg, 20 mol%) were added to the reaction system under O₂ atmosphere. The resulting mixture was then stirred at 80 ℃ for 12 h. When the reaction was completed [monitored by thin-layer chromatography (TLC)], 10 mL of water was added to the reaction system and the mixture was extracted with ethyl acetate. The combined organic phases were dried over anhydrous Na₂SO₄ and concentrated under reduced pressure. The residue was purified by flash column chromatography on silica gel [V(ethyl acetate)∶V(petroleum ether)=1∶15] to afford products 2.

Heterocycles are a highly valuable class of complex scaffolds that are involved in a various kind of well-known organic compounds of industrial and pharmacological importance. Sultine, an important class of sulfur-containing heterocyclic compounds, plays central roles in medicine, biology and material science. The sulfur atom in sultine is located at a vertex of a stable pyramid without identical substituents, making it a chiral center with potential applications in asymmetric synthesis. The asymmetry of sultine can be easily eliminated by oxidizing it into sultone. In addition, sultines have shown to be versatile intermediates in organic synthesis. They can act as useful synthons with hidden bifunctionality: opening the heterocycle at the S—O bond leads to the simultaneous appearance of two functional groups in the product. Despite their potential, the chemical research of sultines have been long neglected and underdeveloped due to their inaccessibility. Only recently, some research groups have discovered protocols for the preparation of these heterocycles and explored their properties using methods such as visible light-induced radical homolytic substitution cyclization and radical polar crossover cyclization, and so on. It is worth noting that although sultines have been discussed in a few reviews, they are not systematic but very fragmentary. Owing to the increasing interest in studies on sultines and their transformations. The synthesis methods, physical properties and applications of sultines are systematically summarized in the past 130 years. The synthetic tactics are reviewed by highlighting their product diversity, selectivity and applicability, along with the mechanistic rationale where possible. Additionally, the chemical transformations of sultines, including photolysis, thermolysis, ring-opening reactions, oxidation/reduction reactions, and rearrangement reactions, are demonstrated. The usefulness of sultines in synthesis, medicine and materials is described as well. Finally, the development status of sultine compounds is reviewed, and a future perspective is provided, in order to offer reference for researchers engaged in sultine chemistry.

Smart bio-adhesive materials are a new type of adhesive that could adhere to tissue surface through bio-adhesion covalent and noncovalent interactions, including hydrogen bonding, electrostatic interactions, cation-π interactions, π-π interactions, Michael addition, Schiff base, amide bond and so on, which usually has a specific response to specific external and internal stimuli, such as in vivo (chemical components, pH, oxidants and enzymes) and in vitro (temperature, ultrasound, light) trigger types. Additionally, smart bio-adhesive materials have attracted great attention in clinical surgical applications due to its numerous advantages, including fast hemostasis, good biocompatibility, strong bio-adhesion, convenient use, simple preparation, excellent repair promoting performance and smart response effect. Among them, light responsive bio-adhesive materials, including ultraviolet (UV) light, visible and near infrared (NIR) light responsive bio-adhesive materials, have unique advantages such as non-contact, spatiotemporal regulation, strict tailoring, accurate positioning, simple operation and remote control, and which have been widely used in wound healing, tissue repair, antibacterial therapy, 3D printing, biomimetics and software devices, cell coating and culture, bio-production and patterning, and other applications. In addition to the widely used UV light responsive bio-adhesive materials, visible and NIR light bio-adhesive materials have received great attention in light responsive biomedical materials and bio-adhesive applications due to its unique features, including excellent and long tissue penetration depth, high stability, low damage to cells and human tissues, and low energy dosage. In this paper, response type of smart bio-adhesive materials is reviewed, and the research progress of UV light, visible and NIR light response bio-adhesive materials in recent years is mainly introduced, including classification, performance and specific application in biomedical field.

Incorporation of fluorine has always been a conventional strategy for designing new drugs and materials because it can usually improve the physiochemical and physiological properties of organic molecules. Among various organofluorine compounds, α-fluoroalkyl alcohols are of particular importance and they are important skeletons of bioactive molecules. Herein, we report a three components olefin difunctionalization reaction for the synthesis of α-fluoroalkyl alcohols through manganese-catalyzed radical Brook rearrangement of α-fluoroalkyl-α-silyl methanols. The operationally simple reaction showed broad substrate scope, and the product could be prepared on gram scale. Twenty-five α-fluoroalkyl alcohols have been synthesized in 44%~86% yields. It is compatible with a variety of halogen substituents (F, Cl, Br), electron donating OMe and naphthalenyl groups and is also suitable for different symmetrical aryl olefins, asymmetric aryl olefins and alkoxyl olefins. The reaction is also compatible with different nucleophiles such as aryl carboxylic acids and anilines. Besides, the reaction is compatible with a α-alkyl alcohol which afford the desired olefin difunctionalization product in 36% yield. A representative procedure is described as follows. In the glovebox, α-difluoromethyl-α-dimethylphenylsilyl methanol (64.8 mg, 0.3 mmol), 1,1-stilbene (223 mg, 0.3 mmol), benzoic acid (110 mg, 0.9 mmol), Mn(OAc)₂ (2.6 mg, 0.015 mmol), tert-butyl peroxybenzoate (TBPB, 175 mg, 0.9 mmol), 4Å MS (30 mg) and dry dichloromethane (DCM, 0.5 mL) were added to a dry 10 mL reaction tube equipped with a magnetic agitator. The reaction mixture was then removed from the glove box, stirred at 70 ℃ for 1 h. Then tetrabutylammonium fluoride (TBAF, 0.36 mmol) was added at 0 ℃. After 30 min, the reaction mixture was quenched with saturated sodium bicarbonate aqueous solution (10 mL), extracted with ethyl acetate (10 mL×3). The organic phase was combined, washed with saturated NaCl aqueous solution and dried with anhydrous sodium sulfate and concentrated under vacuum. Then the crude product was purified by silica gel column chromatography to obtain corresponding target product.

Fluoropolymers exhibit unique properties, such as outstanding thermal stability and chemical inertness, ultralow surface energy, and have found broad applications in lots of areas. Many fluoropolymers show high crystallinity and low solubility, restricting their practical usage through melting and solution processing. To address such issues, copolymerization of fluoroalkenes and comonomers have been developed to prepare fluorinated copolymers that retain fluoroalkyl characteristics and good processibility, bringing many important commercial products, for example, copolymers of chlorotrifluoroethylene (CTFE) and vinyl ethers. However, such copolymers could possess low glass transition temperature (T_g), which is a key property to influence the applicable scope. In this work, we report copolymerization of CTFE and methyl isopropenyl ether (MIE) for the first time, which have enabled the synthesis of novel fluorinated copolymers under LED (light emitting diode) light irradiation conditions by merging an organic thermally activated delayed fluorescence catalyst and a redox active organic amine via a redox-relay catalysis. In comparison to conventional free radical (co)polymerization of fluoroalkenes, this method not only provides main-chain fluoropolymers of readily tunable molecular weights as evidenced by gel permeation chromatography (GPC) and multi-angle light scattering detection coupled with GPC (GPC-MALS), but also allows smooth transformation of fluoroalkene feedstock at ambient pressure using common Schlenk glassware without needing high-pressure metallic vessels. Although the obtained CTFE-MIE copolymers exhibited less controlled molecular weight distributions (MWDs) and limited chain-end fidelity as confirmed by chain-extension polymerization and GPC analysis, the chain-growth process presents first-order kinetics as validated by monitoring the monomer consumption, and follows alternating copolymerization as supported by the variation of degrees of polymerization (DPs) of both vinyl compounds along the light irradiation time, presenting improved chain-growth control as compared to conventional free radical transformation. Notably, as analyzed by differential scanning calorimetry (DSC), in contrast to copolymers of CTFE and ethyl vinyl ether (EVE), the CTFE-MIE copolymers with similar molecular weights exhibit clearly improved T_g of about 50 ℃ via simply introducing methyl substituents on the polymer backbone. Given the broad interests in fluoropolymers and established applications of fluoroalkene-vinyl ether copolymers, we believe that this work should be informative to the rational design of novel fluoropolymers and attractive for material engineering with improved thermal stability.

The excellent processability and cost-effectiveness of petroleum-based plastics render them highly sought-after and extensively utilized across various industries, significantly enhancing convenience in human life and fostering societal progress. However, the disposal methods after use often involved direct incineration and landfill discharge into the natural environment. Due to the ultra-high stability of C—C bonds and high molecular weight, plastics are challenging to degrade in the environment, which poses a significant threat to the environment, life and health, particularly with regards to the increasingly severe issue of "microplastics". The development of biomass materials to replace conventional petroleum-based plastics has become the focal point of attention in the current macro background of the "plastic ban" and the pursuit of "carbon peak" and "carbon neutrality", aiming to address this inherent contradiction. The biomass is highly diverse, originating from natural plants, with a high yield and renewable nature. It is fully biodegradable, biocompatible, environmentally friendly, and serves as an ideal alternative to petroleum-based plastics. The preparation of biodegradable materials with properties similar to petroleum-based plastics from biomass raw materials also encounters numerous technical challenges, including inadequate molding, poor mechanical strength, and low transparency. Therefore, this paper focused on the research progress in the preparation of degradable film materials based on various types of biomass raw materials. Starting from the direct biomass raw materials of starch, pectin and chitosan, and the indirect biomass raw materials of straw, fruit shell and wood, the properties and applications of the obtained bio-based films were reviewed from the sources, composition, structure and extraction of biomass raw materials, as well as film preparation methods, including solvent casting, blow molding, extrusion, electrospinning, etc. Finally, this review examines the limitations and challenges associated with biodegradable films derived from biomass, while also providing a future outlook on research in this field.

Membrane separation technology for CO₂ is a critical means of achieving the carbon peaking and carbon neutrality goals, and the performance of membrane materials significantly impacts the effectiveness of membrane separation. Polyether block amide (Pebax), known for its high permeability and selectivity towards CO₂, along with high mechanical strength and excellent chemical stability, is a highly promising polymer for gas separation membrane materials due to its cost-effectiveness. However, the permeability and selectivity of pure Pebax membranes for CO₂ are still constrained by the “trade-off ” effect. Therefore, the future development direction involves the physical or chemical optimization of Pebax to enhance its gas separation performance. This review introduces the characteristics of Pebax-based membrane materials for CO₂ capture and explores the factors influencing their gas separation performance. The emphasis is on optimizing Pebax preparation processes, promoting transfer membranes, crosslinking, and blending four types of ultra-thin Pebax composite membranes. Additionally, the paper reviews the research progress on Pebax-based mixed matrix membranes and filler functionalization. From the perspective of process improvement, methods such as choosing a shorter chain length of polyamide (PA), increasing casting solution concentration, using solvents with dissolution parameters closer to Pebax, and employing lower drying temperatures contribute to the formation of more regular and higher crystallinity membranes, enhancing gas membrane separation selectivity. Combining grafting, plasma treatment, and other techniques in the preparation of composite membrane materials allows for minimizing the thickness of the Pebax layer to maximize permeability. In facilitated transport membranes, further research is required to explore the “competition-promotion” relationship between water and CO₂ transport for different CO₂ carriers. Reducing the free water content in the membrane will directly limit the generation of CO₂ carriers like bicarbonate, potentially hindering CO₂ dissolution in coordination with functional groups such as carboxylic acids. To overcome the limitations of a single material and achieve new properties that a single component cannot attain, the review suggests selecting multiple polymers or fillers with favorable physical and chemical properties and compatibility at the polymer-filler interface to prepare mixed matrix membranes (MMMs). Choosing porous fillers or polymer materials with good synergistic effects, constructing ternary or even quaternary systems, and directionally controlling the membrane's pore structure and hydrophilic-hydrophobic characteristics hold the potential to break through the trade-off relationship while obtaining superior mechanical strength, durability, and tolerance to harsh operating environments. In conclusion, based on the above findings, this review provides a perspective on the future optimization directions for Pebax-based membrane materials, addressing the current trade-off between permeability and selectivity.

New materials are an important driving force for social development. In recent years, attention on boron-containing materials is growing in the fields of new energy and catalysis, and calls for compelling need for in-depth study of their structure-property relationship to contribute to the research and development of boron-containing materials. In this work, on the aware of the shift of materials research from traditional trial-and-error paradigm to data-driven research paradigm, we explored the application of ten important machine learning algorithms in the prediction of band gaps of boron-containing materials through feature selection (Pearson correlation analysis), grid search-based optimization (Model optimal parameters), and feature importance analysis (interpretability analysis of the model). The results show that the band gap prediction model using the Random Forest algorithm outperforms the other models with a 84% prediction accuracy, and the total magnetization of boron-containing materials is identified to significantly correlate negatively with the band gap, i.e. the smaller the total magnetization of the material, the larger its band gap. The advantage of the Random Forest algorithm over other models is that it is better able to capture correlations between features. For example, the linear model is unable to detect the importance of the total magnetization of boron-containing materials from the material features, thus leading to a lower model prediction performance. This work shows that machine learning methods can be used to guide the design of boron-containing materials with specific band gap. Meanwhile, the results also show that, as an integrated learning model, Random Forest has good learning ability and stable prediction performance, and can be applied to the prediction of band gap and other material properties of other types of material systems, accelerating the design and optimization process of material properties, and is of great scientific significance for the rapid screening and high-performance prediction of new functional materials.

As one of the most basic functional groups in organic molecules, the carbon-carbon triple bond containing two π-bonds harbor great potential for diverse organic transformations. Among them, the functionalization reaction based on the addition of free radicals to alkynes is an effective way to synthesize diverse functionalized olefins, ketones, and even alkane molecules, as well as an important tool for constructing multiple chemical bonds simultaneously. In the last decade, the application of visible light-induced radical reaction strategy for alkyne functionalization has received widespread attention due to it align with the concepts of green chemistry and sustainable development. Nowadays, photoinduced radical functionalization of alkynes has been developed unprecedentically, and many new methods have emerged. Indeed, light-induced radical functionalization reactions of alkynes provide a relatively green approach to the diverse transformations of alkynes. These conversions include hydrofunctionalization, oxidative functionalization, difunctionalization, and so on. These reactions feature mild conditions and easy operation, and do not even require the addition of metals and photosensitizers. Importantly, they provide an efficient way for the construction of valuable skeletons. In particular, the difunctionalization reaction enables the synthesis of high-added-value challenging molecules from simple feedstocks. In these reactions, the alkenyl radicals formed by radical addition to alkynes are the key intermediates. Thus, the type of radical precursor and the further transformation of the alkenyl radical determine the type of chemical bond constructed and the structure of the final product. This paper mainly reviews the new advances in photoinduced radical 1,2-functionalization reactions of alkynes in the past five years, classifying them in terms of the types of chemical bonds constructed, and providing a systematic summary of the types of radicals and reactions. The mechanism and universality of the reactions, as well as its advantages and disadvantages were discussed, and the challenges and opportunities facing the field were outlooked as well.

Introduction of fluorine into organic molecules often causes significant changes in their physical, chemical and biological properties, which result in the wide application of fluorine-containing compounds in many fields of chemistry such as drug discovery, agrochemical development and material science. As a consequence, rapid assembly of fluorinated structures has become one of the most popular research topics in the past decade, which also propelled eminent breakthroughs in related areas. Generally, fluorination methods could be divided into two types according to the fluorinating reagent used, i.e., electrophilic fluorination and nucleophilic fluorination. Compared with electrophilic fluorination, the reagents used in nucleophilic fluorination are usually advantageous in economy and availability. In addition, mild conditions employed in nucleophilic fluorination also result in wide substrate scope and excellent functional group compatibility. By resorting to transition- metal and photoredox catalysis, as well as visible light promoted reactions, the authors’ research group has recently established a series of selective fluorofunctionalization of unsaturated carbon-carbon bonds with nucleophilic fluorine sources, affording a panel of structurally novel fluorine(s)-embedded molecules. In this account, the authors have systematically summarized their recent work in this area, challenges and directions which deserve future endeavors in this field are also discussed.

A smart two-dimensional photonic crystal (2DPC) hydrogel was developed for accurate detection of Hg²⁺ by combining the Debye diffraction effect of 2DPC and the volume phase transition characteristic of hydrogel. The polystyrene (PS) 2DPC arrays were first fabricated by needle-tip-flow method, in which the monodispersed PS microspheres were orderly self-assembled on the water surface to form PS 2DPC and then transferred to glass slide. The poly(acrylamide-allylthiourea) hydrogels embedded with the PS 2DPC arrays were fabricated by “sandwich” method, in which the polymerization precursor solution including monomers acrylamide and allylthiourea was added to the PS 2DPC surface and covered with a glass slide, followed by photopolymerization. The atoms including N, O and S from functional groups on the hydrogel chains selectively coordinated with Hg²⁺, shortening the distance between the hydrogel chains and increasing the crosslinking density of the hydrogel. As a result, the hydrogel shrank and the PS microsphere spacing of the 2DPC decreased, which increased the diameter of the Debye diffraction ring. The microsphere spacing changes were acquired by monitoring Debye diffraction ring diameters before and after the response of the 2DPC hydrogel, achieving the highly sensitive, selective, reversible and fast detection of Hg²⁺. The linear detection ranges were in 10~100 nmol/L and 25~200 μmol/L, and the limit of detection was found to be 3.32 nmol/L. The prepared smart 2DPC hydrogel was used to detect Hg²⁺ in cosmetics and water samples to evaluate its practicability. The recovery for the detection of Hg²⁺ was 98.8%~102.6% and the relative standard deviation was 0.57%~1.09% for a commercially lipstick, and they were 97.2%~103.4% and 0.61%~0.99% for the tap water, respectively. The results demonstrated that our constructed smart 2DPC hydrogels have good applicability, accuracy and reliability for the detection of Hg²⁺ in real samples. The method is simple for testing, only requiring a laser pointer and a ruler, without needing sophisticated instruments, and it can realize portable detection, providing a new strategy for detecting metal ions.

Two photoactivated fluorescent small molecule compounds, TPA-Tz1 and TPA-Tz2, were synthesized by incorporating a 1,2,4,5-tetrazine group into an aggregation-induced emission (AIE) fluorogen. Upon continuous UV light exposure, the fluorescence intensity of TPA-Tz1 and TPA-Tz2 increased by 167-fold and 100-fold, respectively. The photoactivation mechanism of the TPA-Tz1 solution was confirmed using high-resolution mass spectrometry, both before and after illumination, as part of standard verification procedures. The photoactivation mechanism involves the conversion of the tetrazine group to the cyanide group upon light exposure, leading to the restoration of fluorescence emission. Density functional theory (DFT) calculations revealed that the quenching mechanism of TPA-Tz1 involves energy transfer to dark states (ETDS). The fluorescence assessment of photoactivated TPA-CN1 products in solutions with varying water contents revealed distinct AIE characteristics. Specifically, a decline in fluorescence was evident at water contents below 50%, attributable to the twisted intramolecular charge transfer (TICT) effect. Conversely, as water content increased from 60% to 95%, a conspicuous blue shift and enhanced fluorescence were observed. Analysis of the excited states of its dimer, employing time-dependent density functional theory (TDDFT) hole charge analysis, underscored that charge transfer within the aggregated state predominantly accounted for the observed blue shift. The crystal structure of TPA-Tz1, obtained using a solvent evaporation method, unveiled its intricate internal stacked structure. The replacement of π-π interactions by hydrogen bonds and C—H…π interactions played a crucial role in maintaining both lattice stability and AIE. Moreover, cytotoxicity assessments conducted across diverse cell lines demonstrated the biocompatibility of TPA-Tz1, revealing a maximum cell inhibition rate of only 25.3%. Ultimately, photoactivated fluorescence imaging experiments were conducted on cells and Caenorhabditis elegans, utilizing a laser confocal imager for cells and a fluorescence microscope for the organism. The findings illustrated the capability of TPA-Tz1 to facilitate in situ photoactivation imaging at both the cellular and in vivo levels in multicellular organisms.

As a special and important light, circularly polarized light (CPL) has shown unprecedented potentials in the applications of advanced three-dimensional (3D) displays, organic optoelectronic devices, security inks, and biological or chemical probes. Luminescence dissymmetry factor (g_lum) and quantum yields (Φ) are important factors that adopted to evaluate the magnitudes of CPL signals. Most chiral luminescent materials have low g_lum values due to the low magnetic-dipole transition moments. Attributing to the unique photophysical, optoelectronic properties and magnetic-dipole allowed transitions, chiral rare earth materials are promising candidates for circularly polarized luminescent materials possessing both large g_lum and high Φ. Herein, a comprehensive and up-to-date overview of the research progress of rare earth-based circularly polarized luminescent materials is presented, which contains: (i) the developments of visible light, near-infrared light (NIR) and two-photon circularly polarized luminescence; (ii) the effects of ligands, solvents, anions, supermolecular self-assembly, external stimulus on the circularly polarized luminescence performances; (iii) the applications in circularly polarized-organic light-emitting diodes (CP-OLED), biosensing, detection, and security devices. Finally, current challenges and future opportunities are discussed.

The fluorine-containing group has a significant effect on properties such as lipophilicity, permeability, and metabolic stability of compounds. Therefore, the efficient introduction of fluorine-containing groups into pharmaceutical and agrochemical compounds, as well as functional organic materials, has become an important research field of chemistry. Undoubtedly, new methodologies for the efficient and highly selective incorporation of fluorinated substituents into diverse molecular structures continue to be in strong demand. During the past few years, electrosynthesis has been considered to be a practical and environmentally friendly synthetic tool. The application of electrochemical anodic oxidation in synthetic organic chemistry has drawn increasing attention. Electrochemistry utilizes direct interaction of electrons from the anode and cathode with the nucleus, avoids using strong oxidants, and minimizes byproduct formation. Herein we describe an electrochemical synthesis of α-trifluoromethylated ketones from alkenes based on sodium trifluoromethanesulfinate. Sodium trifluoromethanesulfinate generates trifluoromethyl radicals through anodic oxidation to attack the carbon-carbon double bonds of alkenes, and then oxidized in air atmosphere to obtain the target compounds. The optimized reaction conditions of electrochemical synthesis of α-trifluoromethylated ketones are as follows: 1 equiv. of alkenes, 2 equiv. of sodium trifluoromethanesulfinate, a mixture of CH₃CN/H₂O (V∶V=2∶1) as the solvent, 2 equiv. of lithium perchlorate as electrolyte, CF₃COOH as the sacrificial oxidant, graphite as the anode and platinum as the cathode, react at room temperature for 6 h under a constant current of 20 mA and air atmosphere, giving the corresponding α-trifluoromethyl-substituted ketones in 66%~84% yields. The reaction substrate has good applicability, and the reaction conditions are mild. Compared with the traditional methods, the electrocatalytic process avoids the use of peroxidants or expensive photocatalysts. In addition, this reaction can be applied to the synthesis of α-difluoromethylated ketones when using sodium difluoromethanesulfinate instead of sodium trifluoromethanesulfinate.

A previously unreported CO₂ reduction electrocatalyst consisting of MnCe as the active site and melamine foam (MS) as the carrier precursor is proposed. The MS were prepared into carbonized melamine foam (CMS) and graphene oxide- activated melamine foam (GOMS) by activation, respectively. And Mn and Ce were impregnated on the above substrates to synthesize MnCe-CMS and MnCe-GOMS catalysts for the electrocatalytic CO₂ reduction to formic acid. It was found that MnCe-MS (MnCe-CMS and MnCe-GOMS) had a wide potential range (–0.2~–3 V vs. RHE) and better formic acid production ability. Among them, the Faraday efficiency of formic acid (FE_f) on MnCe-CMS was 63.04% at –0.4 V, and the yield rate of formic acid (Y_f) was 470.89 μg•h^–1•cm^–2 at –3.0 V. MnCe-GOMS showed better electrocatalytic activity, with a FE_f of 75.72% at –0.6 V (when the Y_f=661.99 μg•h^–1•cm^–2), and optimal Y_f of 746.9 μg•h^–1•cm^–2 at –0.8 V. In addition, no other products (e.g., acetic acid, methanol, ethanol, CO, methane) were detected during the reaction, suggesting that MnCe-MS has a good formic acid selectivity. Compared with the MnCe-CC, which are based on the commonly used carbon cloth (CC) as a carrier, the Y_f of MnCe-CMS and MnCe-GOMS were increased to 2.3 and 2.8 times, and the FE_f were increased to 2.3 and 2.5 times, respectively, at the optimal potential of MnCe-CC of –0.4 V. This is attributed to the rich pore structure and large electrochemical surface area of the MS material, which can easily form carbon defects during the preparation, thus favoring the adsorption of CO₂. Moreover, under the joint action of Mn and Ce, it effectively promotes electron transport, inhibits the competition reaction of hydrogen precipitation, and forms oxygen vacancies, which is conducive to the adsorption, activation and conversion of CO₂, thus promoting the formation of formic acid.

The physical and chemical properties of polymer strongly depend on the structures of the polymer chain. The structure studies range from the structure of repeat units and their mole fractions to more detailed microstructures, such as molecular weight and its distribution, the sequence of monomer units (block, gradient, alternating, graft, etc.), topology (stars, combs, networks, brushes, etc.), the end-functionalities and tacticity. Among them, the regulation of the polymer tacticity is greatly significant. For example, the stereospecific coordination polymerization of propylene has shown great commercial value. The control of macromolecular structure is difficult for free radical polymerization, although it is one of the most widely used polymerization techniques in the production of polymer materials. The development of reversible deactivated radical polymerization (RDRP) has significantly improved the control over the molecular weight of polymer. However, the regulation of stereoselectivity is extremely challenging for all forms of radical polymerization. One of the reasons is because a terminal carbon of propagating radical takes essentially a neutral sp² planar-like structure without counter species in contrast to an anionic sp³ pyramidal or cationic sp² planar-like structure with counter ion or chiral catalyst site. This brings about a non-stereospecific radical propagation, and results in the energy difference between two enantiomers of an active radical species is small and the energy barrier between the enantiomers is low compared to the thermal energy at the polymerization temperature. In this review, the regulation of stereoselectivity in free radical polymerization are comprehensively summarized, evaluated, and prospected from the perspective of regulation strategies, including polymerization in restricted environment, using monomer containing chiral or bulky substituents, solvent (hydrogen bond) effect, the addition of Lewis acid and catalyst or ligand effect. Although these strategies have achieved some preliminary progress, there are still some problems in general, such as limited monomer scope, high solvent cost, complex reaction system, high Lewis acid loading, low catalytic efficiency and insignificant regulatory effect. The use of controlled radical polymerization catalysts to regulate stereoselectivity is of great potential. In the future, the studies on the radical asymmetric catalysis of small molecule can be used for reference to carefully design the structure of the catalyst and optimize the reaction conditions. In this way, the distance between the catalytic center and the terminal radical of the polymer chain is narrowed, and a confined space environment is created to enhance the stereochemical influence of the catalyst structure on the radical addition polymerization process.

Aromatic amines and their derivatives are widely used as important active intermediates in drugs, dyes and herbicides. Therefore, the development of highly efficient, low-cost, and highly selective catalysts for the hydrogenation of nitroaromatic hydrocarbons is desirable. In this study, Zn-Co metal-organic framework (MOF) materials were synthesized with Zn²⁺/Co²⁺ as the metal source and 2-methylimidazole as an organic ligand at room temperature. Then, a Co catalyst (Co-N-C) was prepared by in-situ pyrolysis using the Zn-Co MOF as a sacrificial template under a nitrogen atmosphere. Aromatic nitro compounds can be selectively converted to the corresponding aromatic amines using ethanol as solvent, hydrazine hydrate as a hydrogen source, and Co-N-C as catalyst. The Co-N-C synthesized by pyrolysis at 1000 ℃ possesses the best catalytic activity. The effects of solvent and reaction time and the amount of Co-N-C, ethanol, and hydrazine hydrate on the catalytic system were investigated. The catalytic effect was the best when 5 mg Co-N-C, 4 mL ethanol, and 4 mmol hydrazine hydrate were added to the system, and the yield of aniline reached 100% after 10 h. Thirty-one different types of nitro-aromatic compounds, including ortho-, meta-, and para-substituted nitroaromatics with electron-donating or electron-withdrawing substituents, nitrobenzene derivatives with other reducible functional groups, and heterocyclic and polycyclic aromatic compounds, were obtained in high yields under this system, which has a wide substrate scope. In addition, the flutamide and nilutamide derivatives and aminoglutethimide were prepared in excellent yields using the Co-N-C catalytic system. The feasibility of the Co-N-C catalytic system was demonstrated using a gram-scale reaction. Cycling and anti-leaching experiments demonstrated that the Co-N-C material has excellent stability and anti-leaching properties, and acts as a reusable heterogeneous catalyst, which can be easily separated and collected by centrifugation. In addition, two reaction mechanisms of direct reduction and condensation reduction of nitro-aromatics using a Co-N-C catalyzed system were proposed by testing the reaction process. This research provides an efficient, simple, and green method for the hydrogenation reduction of nitroaromatics.

Organic solar cells (OSCs) represent a promising frontier in the realm of green energy, characterized by their lightweight design, flexibility, cost-effectiveness, and capacity for large-scale production. This innovative technological advancement serves as a pivotal catalyst in advancing energy cleanliness and promoting sustainable societal progress. An essential objective in the ongoing development of organic solar cells is to elevate their power conversion efficiency to levels comparable to traditional inorganic solar cells, which typically achieve around 20% efficiency. The continuous expansion and deepening of research endeavors have accelerated the scientific progress of OSC, pushing it into a phase of rapid evolution. The persistent advancements in photovoltaic materials and optimization techniques for these devices signal a promising commercial future as device efficiency steadily rises. The structural organization and stability of OSC intricately influence its performance, with the morphology of the active layer playing a pivotal role in determining device power conversion efficiency. In recent years, the integration of additives into OSC has garnered significant attention due to their ability to fine-tune the active layer, ease of application, and remarkable potential for enhancing device performance. This review provides a succinct exploration of the various types, structures, and mechanisms of additives employed in the development of OSC. By categorizing additives based on their molecular structural features, the review identifies four primary groups: non-aromatic cyclic additives, single-cyclic or polycyclic aromatic additives, additives with donor-acceptor (D-A) molecular structures, and additives with complex functions and structures. Each category of additive is meticulously examined to offer a thorough understanding of their mechanisms and the fundamental principles guiding their development. Moreover, the review delves into the future prospects and current challenges associated with the utilization of additives in the OSC domain. It offers invaluable insights to researchers by shedding light on the design and implementation of novel, high-efficiency additives in their upcoming projects. Through this exploration of the multifaceted realm of additives in organic solar cells, the review aims to pave the way for heightened efficiency and efficacy in green energy solutions, contributing to a more sustainable future powered by innovative technologies.

Owing to the continuous development of materials and devices, the power conversion efficiency (PCE) of organic photovoltaics (OPV) has been improved continuously. However, there are some extra treatments used, which are not conducive to the large-scale production of OPV. Reasonably adjusting the solubility, crystallinity, and phase morphology of active layer could be of great importance to simplify processibility and directly obtain high-performance as-cast devices. In this work, a new phenyl substituted benzodithiophenedione unit (m-PhEh-BDD) was designed and synthesized through a facile selective acylation due to the aromatic difference between benzene and thiophene rings. When m-PhEh-BDD used as the third unit to modify the PM6, two new random polymers, namely FBDT-m10 and FBDT-m20 were obtained successfully. For direct comparison, the m-PhEh-BDD-based alternating polymer FBDT-m100 was also synthesized. With the mole content of m-PhEh-BDD moiety increasing, the highest occupied molecular orbital (HOMO) levels of the polymers gradually downshift but their bandgap values almost are identical. Moreover, FBDT-m100 shows less aggregation ability than PM6, suggesting that m-PhEh-BDD unit can modulate the aggregation behavior. Owing to the suitable aggregation and processibility, FBDT-m10 with moderate content of m-PhEh-BDD exhibits the best compatibility with non-fullerene acceptor Y6-BO, resulting in the superior blend morphology. Therefore, the as-cast devices based on FBDT-m10 can obtain the champion PCE of 16.06%, with a good fill factor of 71.14%. Additionally, the FBDT-m10-based device shows better storage stability than that based on PM6. After 7 d of storage, FBDT-m10-based device can maintain 87% of its initial PCE whereas the PM6-based device only kept 58% of its initial PCE. When the m-PhEh-BDD content increasing, the as-cast devices of the same storage time encounter a decrease in PCE, indicating suitable m-PhEh-BDD content is beneficial for long-term stability. This work demonstrates that the further exploitation on phenyl-substituted benzodithiophenedione unit could be a potential venue to achieve promising polymers for high-performing and stable organic solar cells.

In this paper, a novel composite nano diagnostic and therapeutic agent HA-AuNPs/FDF was constructed for highly sensitive fluorescence detection of hyaluronidase (HAase), tumor-targeting fluorescence cell imaging and photodynamic/photothermal synergistic therapy. HA-AuNPs/FDF was formed by the electrostatic self-assembly of FDF, a diketopyrrolopyrrole-based conjugated small molecule, and HA-AuNPs, the gold nanoparticles functionalized with the tumor-targeting biomolecule hyaluronan (HA). FDF generated strong fluorescence under the excitation of near-infrared (NIR) light, and HA-AuNPs will quench the fluorescence of FDF through fluorescence resonance energy transfer (FRET). However, the overexpression of hyaluronidase (HAase) in tumor cells can gradually degrade HA, so FDF was released and the fluorescence of FDF was gradually recovered. Therefore, the fluorescence recovery of HA-AuNPs/FDF can be used for the rapid quantification of HAase. Experiments have shown that this method can achieve good linear response within the range of 0.25~2.25 U/mL with a detection limit of 0.04 U/mL. On this basis, after respective incubation with HA-AuNPs/FDF for 4 h, NIR fluorescence imaging was performed on human cervical cancer tumor cells (HeLa cells), HeLa cells pretreated with HA, and mouse embryonic fibroblasts (NIH-3T3 cells) to study the tumor-targeting capability of HA-AuNPs/FDF. In addition, after incubation with HA-AuNPs/FDF for 20 min, NIR fluorescence imaging was also performed on HeLa cells to detect the changes in fluorescence intensity over time and study the capability of HAase to activate fluorescence. All the results showed that HA-AuNPs/FDF was readily endocytosed by HeLa cells via the receptor CD44 and degraded by intracellular overexpressed HAase, and that it can be successfully used as a fluorescence probe activated by HAase for fluorescence cell imaging of HeLa cells. Furthermore, as FDF is a material with photothermal and photodynamic therapeutic potential, HA-AuNPs/FDF exhibited the single linear oxygen yield of 23.7%, with a photothermal conversion efficiency of 21.3% and good photothermal stability. The cytotoxicity of HA-AuNPs/FDF was measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay and live/dead cell staining experiments using calcein-acetoxymethyl ester (AM) and propidium iodide (PI) double staining kit. The results showed that the number of dead HeLa cells was significantly increased under laser irradiation as compared to that under dark conditions, confirming that HA-AuNPs/FDF can effectively inhibit the proliferation of HeLa cells by photodynamic/photothermal synergistic therapy. This system expands the ideas for achieving precise and efficient tumor diagnosis and therapy.

Nonsymmetric pincer complexes have received much attention due to their hemilability and more easily modulated spatial and electronic effects. However, their synthesis and reactivity studies remain considerably limited in comparison to symmetric pincer complexes. Common strategies to enhance the reactivity of complexes, such as reducing coordination sites or lowering metal center valences, invariably complicate synthesis. In this work, employing the strategy of introducing reducing agents, the PNNCoCl (1) (PNN: [6-(^tBu₂PN)C₅H₃N-2-(3-Mes)C₃H₂N₂]) reacts with various small molecules to yield a variety of nonsymmetric pincer cobalt complexes, which were characterized by single-crystal X-ray diffractometry analysis and spectroscopy. The reaction of PNNCoCl, potassium graphite (or KHBEt₃) with 1 equiv. of CNXyl (2,6-dimethylphenyl isocyanide) or carbon monoxide successfully yielded the monovalent cobalt complexes 2 (PNNCoCNXyl) and 3 (PNNCoCO) in 64% and 41% yields, respectively. Moreover, the reaction of complex 1 with N-heterocyclic carbene (1,3-diisopropyl-4,5-dimethyl-imidazol-2-ylidene), involving C—H bond cleavage and Co—C bond formation, afforded the corresponding divalent cobalt complex 4. Furthermore, by using different reducing agents, we achieved the modulation of the selective reaction of azobenzene C—H or N=N bonds. When KC₈ (potassium graphite) was used as the reducing agent, the reaction of PNNCoCl and azobenzene in tetrahydrofuran afforded the azobenzene C—H bond-breaking product 5 in 53% yield. The cobalt atom is pentacoordinate in a tetragonal pyramid geometry. The N—N lengths of 0.12835(17) nm in complex 5 are in the range of normal N=N double bonds (0.122~0.130 nm). In contrast, the reaction of 1 with azobenzene in the presence of KHBEt₃ gave the cobalt complex PNNCoNHPh (6), as confirmed by X-ray diffraction analysis. The structure suggests N=N double bond cleavage of azobenzene in the formation of the aniline complex. The N—H stretching bands of 6 were recorded at 3131 cm⁻¹, and the solution magnetic moment was µ_eff=2.2 µ_B. In addition, the treatment of complex 1 with 3,5-di-tert-butyl-o-benzoquinone in the presence of 1.2 equiv. of KC₈ gave rise to the cobalt complex 7. X-ray diffraction analysis of 7 revealed that the PNN ligand and o-benzoquinone parts are linked by forming a P—O single bond. The o-benzoquinone was reduced to the catechol ion. Complex 7 exhibits a high-spin electronic structure (S = 3/2), as evidenced by the solution magnetic moment of 4.0 µ_B.

Glycoproteins play important roles in cellular activities and disease development. However, the abundance of glycoproteins is often low in complex biological samples. Thus, it is critical to enrich glycoproteins to achieve highly sensitive mass spectrometry (MS) analysis result. Many methods have been developed to enrich glycoproteins, among which hydrazide chemistry and oxime click chemistry have received increasing attention because of their universality and unbiasedness for labelling glycoproteins. Glycoproteins are captured by covalent binding or high affinity biotin binding on beads in these methods. Therefore, it is difficult to release glycoproteins from beads. Conventional way such as on-bead digestion is too harsh that can co-elute non-specifically bound proteins, endogenously biotinylated proteins and streptavidin on beads. These contaminant proteins would cause background interference in the subsequent glycoprotein identification by MS. In this study, three kinds of cleavable bifunctional probes named Biotin-Azo-Aminooxy (BAA), Biotin-Dde-Aminooxy (BDA) and Biotin-Nbz-Aminooxy (BNA) have been designed and synthesized. The cleavable bifunctional probes allow the release of glycoproteins from beads under mild condition. The mild condition can separate labelled glycoproteins from contaminant proteins to exclude the interference of non-glycoproteins. We evaluated the labelling and enrichment conditions, cleavage efficiency, glycoprotein recovery of these probes. The result showed that the properties of BDA and BNA are excellent. Lastly, BNA was selected to analyze cell surface glycoproteins by MS. Compared with the traditional method of on-bead digestion, the number of non-glycoproteins in this method decreased from 3564 to 2139 by 40.0% and the total Label-free quantitative (LFQ) intensity of glycoproteins increased by 104.2%. Furthermore, the endogenously biotinylated proteins were greatly reduced in cleavage method. The result shows that cleavable bifunctional probes can significantly improve the sensitivity and selectivity of the cell surface glycoprotein identification by MS, which provide tools for deep profiling of glycoproteins in the field of biology and medicine.

Lithium-ion batteries are widely used in various fields of the national economy. However, those with liquid electrolytes may pose potential safety hazards, such as electrolytes leakage, volatilisation, combustion and even explosion. In contrast, solid-state lithium batteries with solid electrolyte exhibit high safety characteristics and have become a research and development hotspot in the scientific and industrial sectors. The design and development of solid-state electrolytes are crucial for solid-state lithium batteries. Poly(ethylene oxide) (PEO) solid polymer electrolyte (SPE) is an excellent electrolyte material for solid-state lithium-metal batteries (SSLBs) due to its high flexibility, excellent processability, good interfacial contact and compatibility with lithium-metal anode. However, the low room temperature ionic conductivity of PEO-based solid polymer electrolytes has seriously restricted its further development and application in the field of room temperature solid polymer lithium metal batteries. Through the continuous efforts of researchers at home and abroad, considerable progress has been made in the development of room-temperature solid-state lithium metal batteries SSLBs with PEO-based solid polymer electrolytes. A detailed description of the research progress room-temperature SSLBs with PEO-based solid-state polymer electrolytes is provided. The strategies covered include nanofiller composites, three-dimensional (3D) skeleton enhancement, molecular level modulation, blending with other polymers, and constructing fast ion transport channels inside the cathode. Finally, a systematic outlook on the challenges and future development trends room-temperature SSLBs with PEO-based solid polymer electrolyte are presented.

Benefit from its exceptional visible light absorption, cost-effectiveness, outstanding stability, and non-toxic, graphitic carbon nitride (GCN) has emerged as an up-and-coming candidate for visible light photocatalysis. Despite these remarkable properties, the practical utilization of these materials as photocatalysts has been hindered by challenges, such as the high recombination rate of photogenerated charge carriers and limited active reaction sites owing to its inherently low surface area. Among the various strategies aimed at overcoming these limitations, controlled manipulation of morphology is recognized as an effective approach for enhancing the photocatalytic performance of carbon nitride. In this investigation, we employed a hydrothermal treatment method involving potassium cyanate to modify pristine GCN, resulting in the production of carbon nitride nanosheets featuring surface defects, which we designate as CCN-m (with 'm' representing the mass of potassium cyanate, while maintaining a constant usage of 2 g of GCN). Specifically, the GCN precursor, synthesized via the melamine condensation process at 550 ℃ for 3 h, was dispersed in a potassium cyanate solution using ultrasonication and stirring. The suspension was then placed in a Teflon-lined autoclave and maintained at 160 ℃ for 8 h. For the photocatalytic assessment, we utilized a Labsolar-6A test system from Perfeclight, employing a 300 W xenon lamp as the incident light source (with a cut-off filter at λ>420 nm). Triethanolamine served as the sacrificial hole agent, and Pt was employed as the co-catalyst. This evaluation revealed that the post-modulation strategy substantially enhanced the photocatalytic capacity of GCN for H₂ evolution. Notably, CCN-4 exhibited an impressive H₂ evolution rate of 319.5 μmol•g⁻¹•h⁻¹, representing a substantial 6.2 times increase compared to pristine GCN. Further characterization through scanning electron microscopy, transmission electron microscopy, and N₂ adsorption-desorption isotherms indicated a reduction in the thickness of carbon nitride and the formation of mesopores, resulting in an increased number of surface reaction sites. X-ray diffraction patterns illustrated a gradual decrease in the layer spacing of carbon nitride with an increasing amount of added potassium cyanate. Photocurrent response, electrochemical impedance spectroscopy, room-temperature solid-state electron paramagnetic resonance (EPR) spectroscopy, and contact angle measurements collectively demonstrated that surface modification reduced interfacial charge transfer resistance and improved charge carrier separation efficiency. This study not only extends the research avenues for hydrothermal intercalation-exfoliation of graphitic carbon nitride but also offers valuable insights into the efficient synthesis of g-C₃N₄ nanosheets with surface defects.

N-benzylidene benzylamine and its derivatives are common functional molecules in organic intermediates, fine chemicals and pharmaceuticals, and have been widely used in medicinal chemistry, materials science and natural product synthesis, such as the synthesis of anticancer and anti-inflammatory agents. Electrochemistry has become a powerful tool in organic synthesis to avoid the use of expensive and toxic oxidants or reductants to reduce the production of harmful and toxic by-products. Therefore, In this paper, we report a method for the synthesis of N-benzylidene benzylamine from dibenzylamine under electrochemical conditions, and its derivatization is studied by a one-pot tandem reaction. N-benzylidene benzylamines were electrolyzed at room temperature with graphite rod (Φ=6 mm) and Pt plate (10 mm×10 mm×0.2 mm) as electrode, ethyl acetate as solvent, and tetrabutylammonium perchlorate (n-Bu₄NClO₄) as electrolyte. Sixteen N-benzylidene benzylamines compounds were successfully prepared by this method, and the GC yield was as high as 96%. The “one-pot method” tandem reaction is a simple, fast and environment-friendly synthesis and preparation method, which uses simple, easy-to-obtain and inexpensive raw materials to prepare complex structures and high-value organic compounds through this “one-pot method” series reaction, without the separation and purification of intermediate products to obtain the required products, especially suitable for reaction systems with unstable intermediate products, which has the advantages of simple operation, simple post-treatment, less product loss, and less waste. In order to highlight the application value of N-benzylidene benzylamines, the derivatization reaction of N-benzylidene benzylamine by one-pot tandem method was further explored. And 15 derivatization products were prepared, isolated yield up to 86%. Finally, through control experiments, salt bridge experiments, cyclic voltammetry experiments and related literature reports, we speculated the possible reaction mechanism of this reaction. The reaction has the characteristics of mild conditions, wide range of substrates, good tolerance of functional groups, without redox agents and insensitivity to air and moisture. This study provides an efficient and economical synthesis strategy for the preparation of N-benzylidene benzylamines derivatives.

Organic luminescent materials have garnered substantial attention within the scientific community owing to their notable attributes, encompassing cost-effectiveness, solution processability, mechanical flexibility, and easily adjustable optoelectronic properties. This multifaceted appeal has propelled their extensive adoption across a spectrum of applications, ranging from organic light-emitting diodes (OLEDs) and organic solid-state lasers (OSSL) to fluorescence imaging methodologies. Nevertheless, the advancement of organic electrically pumped lasers encounters significant hurdles. Organic gain media frequently grapple with challenges such as restricted charge carrier mobility, extended lifetimes of triplet states and polarons, broad absorption profiles, and inadequate stability, all of which pose substantial barriers to the practical realization of these laser systems. In response to these challenges, this study endeavors to introduce voluminous spatial hindrance groups as a prospective solution. These groups are strategically integrated to hinder intermolecular interactions among luminescent molecules, thereby alleviating the inherent luminescent quenching effects of the materials. This intervention not only augments luminescent efficiency but also fortifies the material's stability, addressing pivotal concerns within the discipline. The research methodology encompasses the design and synthesis of two distinct fluorene-based oligomers, namely HTF and ITF, each distinguished by unique spatial configurations. A meticulous examination of their amplified spontaneous emission (ASE) characteristics is conducted under diverse test conditions, incorporating dependencies on annealing temperature and film thickness. The minimum ASE thresholds for HTF and ITF are meticulously determined to be 6.67 and 12.35 µJ/cm², respectively. Furthermore, comparative analyses between HTF and ITF illuminate the distinctive performance attributes of each oligomer. Notably, HTF exhibits superior thermal stability, diminished temperature dependence, and reduced reliance on film thickness in contrast to ITF. Additionally, an evaluation of dibromo-substituted derivatives unveils variable degrees of negative impact on the ASE characteristics of both oligomers following bromine atom substitution, with ITF demonstrating a more pronounced susceptibility. Overall, this comprehensive investigation not only yields valuable insights into the structural design and performance modulation of organic laser gain media but also presents promising avenues for optimizing their efficiency and stability within the domain of optically pumped organic lasers.

Organic synthesis usually requires organic solvents to dissolve reactants or catalysts for reaction, but this leads to serious waste of solvents and environmental pollution. The solvent-free organic synthesis reaction method can effectively avoid resource waste and environmental pollution caused by the use of solvents, and without the use of solvents, the concentration of reactants is the highest, it has significant advantages over reactions in solution in terms of reaction speed, reaction operation, yield, etc. Therefore, solvent-free organic synthesis reaction is favored by organic synthesis chemists as a cleaner and more sustainable synthesis reaction method. However, skeleton structures containing N—N bonds are a very important class of structural units, such as azo compounds, hydrazine derivatives, pyrazole, indazole, triazole derivatives, etc. that exist in various natural products, functional drug molecules, and organic materials. Currently, more than 300 drug molecules have been reported to contain N—N bonds. Especially N,N-disubstituted hydrazine has a wide range of physiological and pharmacological activities, such as antihypertensive, anticancer, and antibacterial. Therefore, we reported using iodobenzenediacetic acid (PIDA) as an oxidant, N-alkoxyamide compounds underwent N—N self coupling reaction at room temperature and solvent-free conditions. This method not only has a simple and easy to operate system, high reaction efficiency, and can prepare products at the gram level, but also has good functional group compatibility, suitable for various substituted benzene rings, aromatic heterocycles, and aliphatic amide substrates. This provides a simple, mild, efficient and potentially useful preparation method for N—N self-coupling of N-alkoxyamide compounds with different substituents. Under this condition, 28 coupling products were prepared with a maximum yield of 96%. The typical procedure is as follows: the mixture of N-alkoxyamide (0.2 mmol, 1 equiv.) and oxidant PIDA (0.15 mmol, 0.75 equiv.) is stirred under a magnetic stirrer until the starting material is completely consumed under thin layer chromatography monitoring. After the reaction, the N—N coupling product was purified by silica gel chromatography.