Macrocycle-Based Porous Organic Polymers for Separation, Sensing, and Catalysis

One pot preparation of magnetic benzylated cyclodextrin-based hyper-cross-linked polymer for phthalate esters extraction from tea beverages

The increasing popularity of packaged beverages has raised concerns about the health risks associated with phthalate esters (PAEs), which are commonly found in plastics used for packaging. This study presents an eco-friendly approach for synthesizing a magnetic benzylated cyclodextrin-based hyper-cross-linked polymer (Fe3O4/BnCD-HCPP), in which FeCl3serves both as a catalyst for the Friedel-Crafts reaction and as an iron source for Fe3O4 nanoparticles. The Fe3O4/BnCD-HCPP composite was used as an adsorbent to extract of PAEs from tea beverages via magnetic solid-phase extraction, followed by gas chromatography-mass spectrometry analysis. The optimized method exhibited excellent sensitivity, with limits of detection ranging from 0.1 to 0.5 μg L-1. Additionally, the method achieved high recovery rates, ranging from 81.5 % to 118.5 %, and demonstrated precision (relative standard deviations <11.6 %) for PAEs spiked into tea beverages. Mechanistic studies indicated that the high extraction efficiency of Fe3O4/BnCD-HCPP for PAEs is due to its favorable pore size distribution, large specific surface area, and multiple interactions, including π-π stacking, hydrophobic force, and host-guest inclusion. This research not only provides an effective method for determining PAEs in complex aqueous matrices but also introduces a novel and sustainable approach for the fabrication of magnetic composites.

Proton-Mediated ROS Amplification in Hydrazone-Linked Pillararene Microspheres for Photocatalysis

Smart materials that adapt to environmental stimuli have massive technological potential. Translating well-established molecular-level responsiveness to macroscopic systems, particularly complex systems for photocatalysis, remains a significant hurdle. Herein, we introduce a new approach using a hydrazone-linked pillararene microsphere (NP5-TF-HPM) as a smart stimuli-responsive photocatalyst. NP5-TF-HPM showcases unique proton responsiveness owing to electron-rich cavities, resulting in a proton-induced structural rearrangement from the enol-imine to keto-amine form. Experiments and density functional theory calculations reveal that pillararenes in the protonated framework function as activity amplifiers. These molecules donate π-electrons from their cavities to another building unit, not only shifting the framework's conduction band to a more negative potential, which enhances its electron-donating capability, but also inducing a nonuniform charge distribution in the donor-acceptor moiety, thereby resulting in an intramolecular built-in electric field. Consequently, protonated HPM exhibits amplified photo-oxidation activity, efficiently catalyzing sulfide photo-oxidation with high conversions (up to 99%).

Regulating Enol-to-Keto Tautomerization of Pillararene-Based Conjugated Macrocycle Polymers for H2O2 Photosynthesis

Porous organic polymers have emerged as promising materials for energy conversion, pollutant adsorption, and heterogeneous catalysis because of their tunable pore structures and high surface areas. However, most porous organic polymers are still limited by insufficient conjugation and inefficient electron-hole separation, hindering the tunability of their photoelectric properties and overall functionality. By integrating macrocyclic compounds as a new building block, which feature electron-rich cavities and rigid ring structures, into the polymer network, the resulting conjugated macrocycle polymers are expected to provide an innovative approach to enrich the photoelectric functionalities of porous organic polymers. Herein, an enaminone-based pillararene photocatalyst, TpAP[5], is constructed by covalently linking functionalized pillar[5]arene to conjugated macrocycle polymers through Schiff base condensation for efficient photocatalytic reactions. This material demonstrates exceptional performance in the photocatalytic production of hydrogen peroxide, achieving a rate of 2343 μmol g-1 h-1. In-depth investigations reveal that the incorporation of pillararenes enables synergistic catalysis of water oxidation and oxygen reduction reactions and significantly enhances catalyst stability by regulating molecular tautomerization. This work opens new avenues for designing high-performance multifunctional conjugated macrocycle polymers with significant potential for clean energy conversion.

Porous polymers: structure, fabrication and application

The porous polymer is a common and fascinating category within the vast family of porous materials. It offers valuable features such as sufficient raw materials, easy processability, controllable pore structures, and adjustable surface functionality by combining the inherent properties of both porous structures and polymers. These characteristics make it an effective choice for designing functional and advanced materials. In this review, the structural features, processing techniques and application fields of the porous polymer are discussed comprehensively to present their current status and provide a valuable tutorial guide and help for researchers. Firstly, the basic classification and structural features of porous polymers are elaborated upon to provide a comprehensive analysis from a mesoscopic to macroscopic perspective. Secondly, several established techniques for fabricating porous polymers are introduced, including their respective basic principles, characteristics of the resulting pores, and applied scopes. Thirdly, we demonstrate application research of porous polymers in various emerging frontier fields from multiple perspectives, including pressure sensing, thermal control, electromagnetic shielding, acoustic reduction, air purification, water treatment, health management, and so on. Finally, the review explores future directions for porous polymers and evaluates their future challenges and opportunities.

Enhanced Conductivity in Conjugated Microporous Polymers via Integrating of Carbon Nanotubes for Ultrasensitive NO2 Chemiresistive Sensor

Conjugated microporous polymers (CMPs) present high promise for chemiresistive gas sensing owing to their inherent porosities, high surface areas, and tunable semiconducting properties. However, the poor conductivity hinders their widespread application in chemiresistive sensing. In this work, three typical CMPs (PSATA, PSATB, and PSATT) are synthesized and their chemiresistive gas sensing performance is investigated for the first time. To further improve performance, PSATT are modified on the surface of amino-functionalized multi-walled carbon nanotubes (NH2-MWCNTs) to improve the conductivity. As a result, the obtained material, PSATT-7NC exhibited a high sensitivity of 9766% toward 4 ppm NO2, which is 2.5 times higher than that of pristine PSATT. It also demonstrated remarkable selectivity and excellent long-term stability. Furthermore, the lowest limit of detection (0.79 ppb) among all polymers-based sensors is achieved at a low operating temperature of 100 °C. This work provides a valuable strategy into the development of a new material platform for advancing high-performance gas sensing applications.

Porous Organic Polymers Incorporating Shape-Persistent Cyclobenzoin Macrocycles for Organic Solvent Separation

The recovery and separation of organic solvents is highly important for the chemical industry and environmental protection. In this context, porous organic polymers (POPs) have significant potential owing to the possibility of integrating shape-persistent macrocyclic units with high guest selectivity. Here, we report the synthesis of a macrocyclic porous organic polymer (np-POP) and the corresponding model compound by reacting the cyclotetrabenzil naphthalene octaketone macrocycle with 1,2,4,5-tetraaminobenzene and 1,2-diaminobenzene, respectively, under solvothermal conditions. Co-crystallization of the macrocycle and the model compound with various solvent molecules revealed their size-selective inclusion within the macrocycle. Building on this finding, the np-POP with a hierarchical pore structure and a surface area of 579 m2 g-1 showed solvent uptake strongly correlated with their kinetic diameters. Solvents with kinetic diameters below 0.6 nm - such as acetonitrile and dichloromethane - showed high uptake capacities exceeding 7 mmol g-1. Xylene separation tests revealed a high overall uptake (~34 wt %), with o-xylene displaying a significantly lower uptake (~10 wt % less than other isomers), demonstrating the possibility of size and shape selective separation of organic solvents.

Functional crystalline porous framework materials based on supramolecular macrocycles

Crystalline porous framework materials like metal-organic frameworks (MOFs) and covalent-organic frameworks (COFs) possess periodic extended structures, high porosity, tunability and designability, making them good candidates for sensing, catalysis, gas adsorption, separation, etc. Despite their many advantages, there are still problems affecting their applicability. For example, most of them lack specific recognition sites for guest uptake. Supramolecular macrocycles are typical hosts for guest uptake in solution. Macrocycle-based crystalline porous framework materials, in which macrocycles are incorporated into framework materials, are growing into an emerging area as they combine reticular chemistry and supramolecular chemistry. Organic building blocks which incorporate macrocycles endow the framework materials with guest recognition sites in the solid state through supramolecular interactions. Distinct from solution-state molecular recognition, the complexation in the solid state is ordered and structurally achievable. This allows for determination of the mechanism of molecular recognition through noncovalent interactions while that of the traditional recognition in solution is ambiguous. Furthermore, crystalline porous framework materials in the solid state are well-defined and recyclable, and can realize what is impossible in solution. In this review, we summarize the progress of the incorporation of macrocycles into functional crystalline porous frameworks (i.e., MOFs and COFs) for their solid state applications such as molecular recognition, chiral separation and catalysis. We focus on the design and synthesis of organic building blocks with macrocycles, and then illustrate the applications of framework materials with macrocycles. Finally, we propose the future directions of macrocycle-based framework materials as reliable carriers for specific molecular recognition, as well as guiding the crystalline porous frameworks with their chemistry, applications and commercialization.

β-cyclodextrin polymers as a new sorbent for solid-phase extraction of xenobiotics in Urine

This study systematically assessed the performance of a newly developed solid-phase extraction (SPE) material, cellulose-supported aminated β-cyclodextrin polymer (amine-β-CDP@Cellulose), in determining 44 xenobiotics, encompassing endocrine-disrupting chemicals (EDCs), pharmaceuticals, and food additives in urine samples. The primary objective of the research was to synthesize a new sorbent, optimize the extraction protocol, and elucidate the underlying adsorption and desorption mechanisms. Following optimization, it was observed that amine-β-CDP@Cellulose achieved recoveries ranging from 80 % to 120 % for 28 of the 44 targeted xenobiotics, with only three compounds showing recoveries below 50 %. The superior extraction performance of this novel material can be attributed to the synergistic effects of its structural components: charged functional groups introduced via the cross-linking agent, the hydrophobic cyclodextrin cavity that facilitates inclusion complexation, and abundant hydroxyl groups that enhance adsorption. Additionally, the study included a comparative analysis between amine-β-CDP@Cellulose and commercially available HLB resins. This comparative analysis revealed that the amine-β-CDP@Cellulose method effectively mitigated matrix interferences while maintaining comparable extraction efficiency to the HLB-based method. Collectively, these findings suggest that amine-β-CDP@Cellulose could serve as a sustainable and cost-effective material for extracting xenobiotics from complex matrices.

Neighboring Chalcogen Bonding for Controlling Dynamic Imine Chemistry in Aqueous Media

The impact of varied chalcogen bonds (sulfur, selenium, tellurium, and telluronium) on dynamic imine chemistry in aqueous solution is presented by introducing a carboxylate group or cationic telluronium into arylaldehydes. The role of chalcogen bonding in regulating the kinetics and thermodynamics of imine formation/exchange was elucidated through experimental and computational evidence, affording the largest effect for tellurium/telluronium compounds. By leveraging multivalent chalcogen bonding, telluronium-containing aldehyde enabled labeling of the N-terminus of amino acids in neutral buffer.

Enantioselective construction of inherently chiral pillar[5]arenes via palladium-catalysed Suzuki-Miyaura cross-coupling

Pillar[n]arenes have broad applications in biological medicine, materials science, and supramolecular gels. Notably, enantiopure pillar[5]arenes are valued for their roles in enantioselective host-guest recognition, chiral sensing, asymmetric catalysis, and related fields. Current methods for obtaining chiral pillar[n]arenes rely heavily on resolution agents or chiral HPLC resolution. However, the synthesis of these compounds via asymmetric catalysis remains challenging. In this study, we develop an asymmetric extended side-arm Suzuki-Miyaura cross-coupling strategy to construct inherently chiral pillar[5]arenes with excellent yields and high enantioselectivities using a palladium catalyst and a Sadphos ligand. The reaction scope extends beyond arylboronic acids to encompass 2-arylvinylboronic acids and other multi-OTf-substituted substrates, all efficiently producing the desired products. Further exploration of the synthetic applications, along with photophysical and chiroptical analyses, confirm the potential of these chiral pillar[5]arenes for diverse applications across multiple disciplines.

Thiolated non-conjugated nano polymer network for advanced mercury removal from water

Developing advanced adsorbents for selectively deducing mercury (Hg) in water to one billionth level is of great significance for public health and ecological security, but achieving the balance among efficiency, cost and environmental friendliness of adsorbents still faces enormous challenges. Herein, we present a high thiol content non-conjugated nano polymer network (PVB-SH) through simple microemulsion polymerization for efficient Hg ion (Hg(II)) removal. The PVB-SH is prepared by conventional commercial reagents and does not consume toxic organic solutions. This nano network reveals uniformly distributed nano sizes, leading to good accessibility of adsorption sites. The long and flexible polymer chains in the network allow two thiol sites to coordinate with one Hg(II), displaying significantly stronger binding than 1:1 coordination. Therefore, PVB-SH shows high affinity toward Hg(II) (Kd = 3.04 × 107 mL/g) and can selectively reduce Hg(II) in water to extremely low level of 0.14 μg/L, well below the safe limit of 2 μg/L. PVB-SH possesses excellent renewability (removal efficiency = 99.58 % after 10 regenerations), good resistance to various environmental factors (pH, ions and organic matter) and long-term stability in acid, alkali, and salt solutions. Impressively, PVB-SH is further made into a membrane by simple phase-inversion and can effectively purify 1592.4 L/m2 Hg(II) polluted drinking water before the breakthrough point of 2 μg/L. These results demonstrate the good practical potential of PVB-SH for decontamination of Hg from aqueous media.

Advanced Porous Aromatic Frameworks: A Comprehensive Overview of Emerging Functional Strategies and Potential Applications

Porous aromatic frameworks (PAFs) are a fundamental group of porous materials characterized by their distinct structural features and large surface areas. These materials are synthesized from aromatic building units linked by strong carbon-carbon bonds, which confer exceptional rigidity and long-term stability. PAFs functionalities may arise directly from the intrinsic chemistry of their building units or through the postmodification of aromatic motifs using well-defined chemical processes. Compared to other traditional porous materials such as zeolites and metallic-organic frameworks, PAFs demonstrate superior stability under severe chemical treatments due to their robust carbon-carbon bonding. Even in challenging environments, the chemical stability and ease of functionalization of PAFs demonstrate their flexibility and specificity. Research on PAFs has significantly expanded and accelerated over the past decade, necessitating a comprehensive overview of key advancements in this field. This review provides an in-depth analysis of the recent advances in the synthesis, functionalization, and dimensionality of PAFs, along with their distinctive properties and wide-ranging applications. This review explores the innovative methodologies in PAFs synthesis, the strategies for functionalizing their structures, and the manipulation of their dimensionality to tailor their properties for specific potential applications. Similarly, the key application areas, including batteries, absorption, sensors, CO2 capture, photo-/electrocatalytic usages, supercapacitors, separation, and biomedical are discussed in detail, highlighting the versatility and potential of PAFs in addressing modern scientific and industrial challenges.

2,3 : 6,7-Naphthalenediimide-Based Chiral Triangular Macrocycle: Self-Assembled Helix, Outer π-Surface Directed Co-Assembly and Circularly Polarized Luminescence

Here, we report the synthesis and self-assembly of a novel chiral 2,3 : 6,7-naphthalenediimide-based triangular macrocycle (NDI-Δ) and its chiroptical properties. The enantiomeric NDI-Δ is synthesized by condensation of (RR) or (SS)-trans-1,2-cyclohexanediamine and 2,3,6,7-naphthalenetetracarboxylic 2,3 : 6,7-dianhydride, in which the chirality of the macrocycles is controlled by the diamine. With the rigid outer π-surface, the macrocycle exhibits unique chiroptical properties and self-assembly modes. The NDI-Δ shows circularly polarized luminescence (CPL) in solution and can self-assemble into helical structures with the inversion of CPL signal and the enhancement of |glum|. Moreover, the NDI-Δ has a tailored electron-deficient outer π-surface, which can co-assemble with an electron-rich anthracene (AN) to form an intermolecular charge transfer (CT) complex, generating a yellow-green CT-CPL. Crystal structure analysis confirms that AN is mounted on the outer surface of NDI-Δ through π-π stacking and C-H ⋯ ${\cdots }$ π interactions. This work provides a critical example for the self-assembly of macrocycles into helical structures and outer π-surface directed CT complexes formation, opening up a new clue for designing chiral macrocycle-based chiroptical materials.

Photoswitchable Topological Regulation of Covalent Macrocycles, Molecular Recognition, and Interlocked Structures

Macrocycles represent one important class of functional molecules, and dynamic macrocycles with the potential of cleavability, adaptability, and topological conversion are challenging. Herein we report photoswitchable allosteric and topological control of dynamic covalent macrocycles and further the use in guest binding and mechanically interlocked molecules. The manipulation of competing ring-chain equilibria and bond formation/scission within reaction systems enabled light-induced structural regulation over dithioacetal and thioacetal dynamic bonds, accordingly realizing bidirectional switching between crown ether-like covalent macrocycles and their linear counterparts. The on-demand photoswitchable topological transformation of macrocycles further allowed guest recognition/release exhibiting controllable binding affinity and selectivity. To showcase the capability light-triggered assembly/disassembly of diverse mechanically interlocked structures, such as rotaxanes and catenanes, was achieved. The realization of photoswitchable topological conversion of covalent macrocycles, which has been rarely reported before, demonstrates the potential of light-triggered reactivity control and structural reconfiguration for enhanced complexity and sophisticated function. The strategies and results should be appealing to endeavors in molecular recognition, dynamic assemblies, molecular machines, and intelligent materials.

Construction of Supramolecular Polymer Network Elastomers Based on Pillar[5]arene/Alkyl Chain Host-Guest Interactions

As a special kind of supramolecular compound with many favorable properties, pillar[n]arene-based supramolecular polymer networks (SPNs) show potential application in many fields. Although we have come a long way using pillar[n]arene to prepare SPNs and construct a series of smart materials, it remains a challenge to enhance the mechanical strength of pillar[n]arene-based SPNs. To address this issue, a new supramolecular regulation strategy was developed, which could precisely control the preparation of pillar[n]arene-based SPN materials with excellent mechanical properties by adjusting the polymer network structures. Specifically, we utilized the host-guest interaction between pillar[5]arene and the alkyl chain of butyl acrylate monomer to form a supramolecular polymer network and achieved the transformation of different states by regulating the cross-linking density of the polymer networks. Additionally, the polymer networks exhibited good stimuli responsiveness as well as excellent dynamic properties and reconfigurable characteristics through a temperature change and the addition of competitive hosts or guests. The research provided new possibilities for the development of polymer materials.

Covalent Organic Frameworks for Membrane Separation

Membranes with switchable wettability, solvent resistance, and toughness have emerged as promising materials for separation applications. However, challenges like limited mechanical strength, poor chemical stability, and structural defects during membrane fabrication hinder their widespread adoption. Covalent organic frameworks (COFs), crystalline materials constructed from organic molecules connected by covalent bonds, offer a promising solution due to their high porosity, stability, and customizable properties. The ordered structures and customizable functionality provide COFs with a lightweight framework, large surface area, and tunable pore sizes, which have attracted increasing attention for their applications in membrane separations. Recent research has extensively explored the preparation strategies of COF membranes and their applications in various separation processes. This review uniquely delves into the influence of various COF membrane fabrication techniques, including interfacial polymerization, layer-by-layer assembly, and in situ growth, on membrane thickness and performance. It comprehensively explores the design strategies and potential applications of these methods, with a particular focus on gas separation, oil/water separation, and organic solvent nanofiltration. Furthermore, future opportunities, challenges within this field, and potential directions for future development are proposed.

Exploring Supramolecular Frustrated Lewis Pairs

Frustrated Lewis pairs (FLPs) have rapidly become one of the key metal-free catalysts for a variety of chemical transformations. Embedding these catalysts within a supramolecular assembly can offer improvements to factors such as recyclability and selectivity. In this review we discuss advances in this area, covering key supramolecular assemblies such as metal organic frameworks (MOFs), covalent organic frameworks (COFs), polymers and macrocycles.

Phenyl-Extended Resorcin[4]arenes: Synthesis and Highly Efficient Iodine Adsorption

The continuous exploration of new analogs of calixarenes and pillararenes unlocks infinite opportunities in supramolecular chemistry and materials. In this work, we introduce a new class of macrocycle, phenyl-extended resorcin[4]arenes (ExR4), a unique and innovative design that incorporates unsubstituted phenylene moieties into the resorcin[4]arene scaffold. Single-crystal analysis reveals a chair-like conformation for per-methylated ExR4 (Me-ExR4) and a twisted "Figure-of-eight" shaped conformation for per-hydroxylated ExR4 (OH-ExR4). Notably, OH-ExR4 demonstrates exceptional adsorption capability toward I3 - ions in an aqueous solution, with a rapid kinetic rate of 1.18×10-2 g ⋅ mg-1 ⋅ min-1. Furthermore, OH-ExR4 shows excellent recyclability and potential as a stationary phase in column setups. The discovery of ExR4 opens up new avenues for constructing new macrocycles and inspires further research in functional adsorption materials for water pollutant removal.

Supramolecular-macrocycle-based functional organic cocrystals

Supramolecular macrocycles, renowned for their remarkable capabilities in molecular recognition and complexation, have emerged as pivotal elements driving advancements across various innovative research fields. Cocrystal materials, an important branch within the realm of crystalline organic materials, have garnered considerable attention owing to their simple preparation methods and diverse potential applications, particularly in optics, electronics, chemical sensing and photothermal conversion. In recent years, macrocyclic entitles have been successfully brought into this field, providing an essential and complementary channel to create novel functional materials, especially those with multiple functionalities and smart stimuli-responsiveness. In this Review, we present an overview of the research efforts on functional cocrystals constructed with macrocycles, covering their design principles, preparation strategies, assembly modes, and diverse functions and applications. Finally, the remaining challenges and perspectives are outlined. We anticipate that this review will serve as a valuable and timely reference for researchers interested in supramolecular crystalline materials and beyond, catalyzing the emergence of more original and innovative studies in related fields.

Fabrication of Azacrown Ether-Embedded Covalent Organic Frameworks for Enhanced Cathode Performance in Aqueous Ni-Zn Batteries

Crown ethers (CEs), known for their exceptional host-guest complexation, offer potential as linkers in covalent organic frameworks (COFs) for enhanced performance in catalysis and host-guest binding. However, their highly flexible conformation and low symmetry limit the diversity of CE-derived COFs. Here, we introduce a novel C3-symmetrical azacrown ether (ACE) building block, tris(pyrido)[18]crown-6 (TPy18C6), for COF fabrication (ACE-COF-1 and ACE-COF-2) via reticular synthesis. This approach enables precise integration of CEs into COFs, enhancing Ni2+ ion immobilization while maintaining crystallinity. The resulting Ni2+-doped COFs (Ni@ACE-COF-1 and Ni@ACE-COF-2) exhibit high discharge capacity (up to 1.27 mAh ⋅ cm-2 at 8 mA ⋅ cm-2) and exceptional cycling stability (>1000 cycles) as cathode materials in aqueous alkaline nickel-zinc batteries. This study serves as an exemplar of the seamless integration of macrocyclic chemistry and reticular chemistry, laying the groundwork for extending the macrocyclic-synthon driven strategy to a diverse array of COF building blocks, ultimately yielding advanced materials tailored for specific applications.

Interconversion and functional composites of metal-organic frameworks and hydrogen-bonded organic frameworks

Metal-organic frameworks (MOFs), an emerging class of highly ordered crystalline porous materials, possess structural tunability, high specific surface area, well-defined pores, and diverse pore environments and morphologies, making them suitable for various potential applications. Moreover, hydrogen-bonded organic frameworks (HOFs), constructed from organic molecules with complementary hydrogen-bonding patterns, are rapidly evolving into a novel category of porous materials due to their facile mild preparation conditions, solution processability, easy regeneration capability, and excellent biocompatibility. These distinctive advantages have garnered significant attention across diverse fields. Considering the inherent binding affinity between MOFs and HOFs along with the fact that many MOF linkers can serve as building blocks for constructing HOFs, their combination holds promise in creating functional materials with enhanced performance. This feature paper provides an introduction to the interconversion between MOFs and HOFs followed by highlighting the emerging applications of MOF-HOF composites. Finally, we briefly discuss the current challenges associated with future perspectives on MOF-HOF composites.

Conjugated Microporous Polymers-Based Catalytic Membranes with Hierarchical Channels for High-Throughput Removal of Micropollutants

Engineering a catalytic membrane capable of efficiently removing emerging organic microcontaminants under ultrahigh flux conditions is of significance for water purification. Herein, drawing inspiration from the functional attributes of lymphatic vessels involved in immunosurveillance and fluid transport with minimal energy consumption, a novel hierarchical porous catalytic membrane is engineered. This membrane, based on an innovative nitrogen-rich conjugated microporous polymer (polytripheneamine, PTPA), is synthesized using an electrospinning coupled in situ polymerization approach. The resulting bioinspired membrane with hierarchical channels comprises a thin layer (≈1.7 µm) of crosslinked PTPA nanoparticles covering the interconnected electrospun nanofibers. This unique design creates an intrinsic microporous angstrom-confined system capable of activating peroxymonosulfate (PMS) to generate 98.7% singlet oxygen (1O2), enabling durable and highly efficient degradation of microcontaminants. Additionally, the presence of a thin layer of mesoporous structure between PTPA nanoparticles and macroporous channels within the interwoven nanofibers enhances mass transfer efficiency and facilitates high flux rates. Notably, the prepared hierarchical porous organic catalytic membrane demonstrates enduring high-efficiency degradation performance with a superior permeance (>95% and >2500 L m-2 h-1 bar-1) sustained over 100 h. This work introduces an innovative pathway for the design of high-performance catalytic membranes for the removal of emerging organic microcontaminants.

Dipolar Microenvironment Engineering Enabled by Electron Beam Irradiation for Boosting Catalytic Performance

Creating a diverse dipolar microenvironment around the active site is of great significance for the targeted induction of intermediate behaviors to achieve complicated chemical transformations. Herein, an efficient and general strategy is reported to construct hypercross-linked polymers (HCPs) equipped with tunable dipolar microenvironments by knitting arene monomers together with dipolar functional groups into porous network skeletons. Benefiting from the electron beam irradiation modification technique, the catalytic sites are anchored in an efficient way in the vicinity of the microenvironment, which effectively facilitates the processing of the reactants delivered to the catalytic sites. By varying the composition of the microenvironment scaffold structure, the contact and interaction behavior with the reaction participants can be tuned, thereby affecting the catalytic activity and selectivity. As a result, the framework catalysts produced in this way exhibit excellent catalytic performance in the synthesis of glycinate esters and indole derivatives. This manipulation is reminiscent of enzymatic catalysis, which adjusts the internal polarity environment and controls the output of products by altering the scaffold structure.

Thermal-Sensitive Supramolecular Coordination Complex Formed by Orthogonal Metal Coordination and Host-Guest Interactions for an Electrical Thermometer

Supramolecular coordination complexes (SCCs) are popular for their structural diversity and functional adaptability, which make them suitable for a wide range of applications. Photophysical and mechanical performance of SCCs are the most attractive characteristics, yet their ionically conductive behavior and potential in electrical sensing have been rarely investigated. This study reports a well-designed SCC that integrates orthogonal metal coordination and host-guest interactions to achieve sensitive electrical thermal sensing. Owing to the thermodynamic nature of the host-guest interaction, the SCC encounters thermally induced disassembly, leading to significantly enhanced ion mobility and thus allowing for the precise detection of minor temperature variation. The SCC-based thermometer is then fabricated with the assistance of 3D printing and demonstrates good accuracy and reliability in monitoring human skin temperature and real-time temperature changes of mouse during the whole anesthesia and recovery process. Our findings provide an innovative strategy for developing electrical thermometers and expand the current application scope of SCCs in electrical sensing.

Electrochemical Formation of Ionic Porous Organic Polymers Based on Viologen for Electrochromic Applications

The systematic study of two ionic porous organic polymers (iPOPs) based on viologens and their first applications in the electrochromic field are reported. The viologen-based iPOPs are synthesized by electrochemical polymerization with cyano groups, providing a simple and controllable method for iPOPs that solves the film preparation problems common to viologens. After the characterization of these iPOPs, a detailed study of their electrochromic properties is conducted. The iPOP films based on viologens structure exhibit excellent electrochromic properties. In addition, the resulting iPOP films show high sensitivity to electrolyte ions of different sizes in the redox process. Electrochemical and electrochromic data of the iPOPs explain this phenomenon in detail. These results demonstrate that iPOPs of this type are ideal candidates as electrochromic materials due to their inherent porous structures and ion-rich properties.

Coordinating nature of M6L12 double-stranded macrocycles: co-ligand competition of perchlorate, water, and acetonitrile depending on metal(II) ions

Self-assembly of M(ClO4)2 (M(II) = Mn(II), Co(II), Ni(II), Cu(II), and Zn(II)) with dicyclopentyldi(pyridine-3-yl)silane (L) as a donor in a mixture of acetonitrile and toluene produces crystals consisting of M6L12 double-stranded macrocycles. The geometry around the M(II) cations is a typical octahedral arrangement, but the metallamacrocycles' outer axial coordination environment is sensitive to the M(II) cations. The conformation of the unique metallamacrocycles is informatively dependent on the nature of the coordination around the M(II) cations via subtle co-ligand competition among perchlorate anions, water, and acetonitrile. Both the coordinated acetonitriles and the solvate molecules of the crystals are removed at 170 °C, thereby transforming the crystals into new crystals that return to their original form in the mixture of toluene and acetonitrile. Catalytic oxidation of 3,5-di-tert-butylcatechol using [Cu6(ClO4)8(CH3CN)4L12]4ClO4·5C7H8 is much faster than those using the transformed product, [Cu(ClO4)2L2], and a simple mixture of Cu(ClO4)2 + L.

Scalable Preparation of Ultraselective and Highly Permeable Fully Aromatic Polyamide Nanofiltration Membranes for Antibiotic Desalination

Membranes are important in the pharmaceutical industry for the separation of antibiotics and salts. However, its widespread adoption has been hindered by limited control of the membrane microstructure (pore architecture and free-volume elements), separation threshold, scalability, and operational stability. In this study, 4,4',4'',4'''-methanetetrayltetrakis(benzene-1,2-diamine) (MTLB) as prepared as a molecular building block for fabricating thin-film composite membranes (TFCMs) via interfacial polymerization. The relatively large molecular size and rigid molecular structure of MTLB, along with its non-coplanar and distorted conformation, produced thin and defect-free selective layers (~27 nm) with ideal microporosities for antibiotic desalination. These structural advantages yielded an unprecedented high performance with a water permeance of 45.2 L m-2 h-1 bar-1 and efficient antibiotic desalination (NaCl/adriamycin selectivity of 422). We demonstrated the feasibility of the industrial scaling of the membrane into a spiral-wound module (with an effective area of 2.0 m2). This module exhibited long-term stability and performance that surpassed those of state-of-the-art membranes used for antibiotic desalination. This study provides a scientific reference for the development of high-performance TFCMs for water purification and desalination in the pharmaceutical industry.

An ambipolar PEDOT-perfluorinated porphyrin electropolymer: application as an active material in energy storage systems

The development of functional organic materials is crucial for the advancement of various fields, such as optoelectronics, energy storage, sensing, and biomedicine. In this context, we successfully prepared a stable ambipolar perfluoroporphyrin-based polymeric film by electrochemical synthesis. Our strategy involved the synthesis of a novel tetra-pentafluorophenyl porphyrin covalently linked to four 3,4-ethylenedioxythiophene (EDOT) moieties. The resulting monomer, EDOT-TPPF16, was obtained through a straightforward synthetic approach with a good overall yield. The unique molecular structure of EDOT-TPPF16 serves a dual function, with EDOT moieties allowing electropolymerization for polymeric film formation, while the electron-acceptor porphyrin core enables electrochemical reduction and electron transport. The electrochemical polymerization permits the polymer (PEDOT-TPPF16) synthesis and film formation in a reproducible and controllable manner in one step at room temperature. Spectroelectrochemical experiments confirmed that the porphyrin retained its optoelectronic properties within the polymeric matrix after the electrochemical polymerization. The obtained polymeric material exhibited stable redox capabilities. Current charge-discharge cycles and electrochemical impedance spectroscopy of the electrochemically generated organic film demonstrated that the polymer could be applied as a promising active material in the development of supercapacitor energy storage devices.

Chiral BINOL-phosphate assembled single hexagonal nanotube in aqueous solution for confined rearrangement acceleration

Creating microenvironments that mimic an enzyme's active site is a critical aspect of supramolecular confined catalysis. In this study, we employ the commonly used chiral 1,1'-bi-2-naphthol (BINOL) phosphates as subcomponents to construct supramolecular hollow nanotube in an aqueous medium through non-covalent intermolecular recognition and arrangement. The hexagonal nanotubular structure is characterized by various techniques, including X-ray, NMR, ESI-MS, AFM, and TEM, and is confirmed to exist in a homogeneous aqueous solution stably. The nanotube's length in solution depends on the concentration of chiral BINOL-phosphate as a monomer. Additionally, the assembled nanotube can accelerate the rate of the 3-aza-Cope rearrangement reaction by up to 85-fold due to the interior confinement effect. Based on the detailed kinetic and thermodynamic analyses, we propose that the chain-like substrates are constrained and pre-organized into a reactive chair-like conformation, which stabilizes the transition state of the reaction in the confined nanospace of the nanotube. Notably, due to the restricted conformer with less degrees of freedom, the entropic barrier is significantly reduced compared to the enthalpic barrier, resulting in a more pronounced acceleration effect.

Luminescent Porous Organic Crystals for Adsorptive Separation of Toluene and Methylcyclohexane

A butterfly-shaped phenothiazine derivative, PTTCN, was synthesized to obtain pure organic porous crystals for the highly efficient absorptive separation of toluene (Tol) and methylcyclohexane (Mcy). Due to the presence of three polar cyano groups and nonplanar conformation, these molecules self-assembled into a hydrogen-bonded organic framework (X-HOF-5) with distinct cavities capable of accommodating Tol molecules through multiple hydrogen-bonding interactions. Upon solvent removal via heating, the activated X-HOF-5 retained its cavity structure albeit with altered stacking arrangements, accompanied by a remarkable fluorescent color change from cyan to green. X-HOF-5a can undergo a phase transformation into X-HOF-5 upon reabsorption of Tol, while exhibiting no accommodation of Mcy due to the weak intermolecular interaction between PTTCN and Mcy. This suggests that the activated HOF material prefers Tol over Mcy. Moreover, X-HOF-5a may selectively accommodate Tol in a Tol/Mcy equimolar mixture, and the purity of Tol can reach 97% after release from the framework. Additionally, it is noteworthy that the HOF material exhibits recyclability without any discernible loss in performance.

Recent progress in iodine capture by macrocycles and cages

The effective capture of radioiodine is vital to the development of the nuclear industry and ecological environmental protection. There is, therefore, a continuously growing research exploration in various types of solid-state materials for iodine capture. During the last decade, the potential of using macrocycle and cage-based supramolecular materials in effective uptake and separation of radioactive iodine has been demonstrated. Interest in the application of these materials in iodine capture originates from their diversified porous characteristics, abundant host-guest chemistry, high iodine affinity and adsorption capacity, high stability in various environments, facile modification and functionalization, and intrinsic structural flexibility, among other attributes. Herein, recent progress in macrocycle and cage-based solid-state materials, including pure discrete macrocycles and cages, and their polymeric forms, for iodine capture is summarized and discussed with an emphasis on iodine capture capacities, mechanisms, and design strategies.

Azo-Linked Porous Polycalix[n]arenes for the Efficient Removal of Organic Micropollutants from Water

Developing novel porous adsorbents for efficient wastewater treatment is significant to the environment protection. Herein, three porous polycalix[n]arenes (n = 4, 6, and 8) which had varying cavity sizes of the macrocycle (Azo-CX4P, Azo-CX6P, and Azo-CX8P) were prepared under mild conditions and tested for their potential application in water purification. Azo-CX8P with a larger cavity size of the macrocycle outperformed Azo-CX4P and Azo-CX6P in screening studies involving a range of organic micropollutants. It was proved that Azo-CX8P was especially efficient in the removal of cationic dyes because of its high negative surface charge. In terms of the adsorption of Rhodamine B with Azo-CX8P, the pseudo-second-order rate constant reaches 5.025 g·mg-1·min-1 with the maximum adsorption capacity being 1345 mg·g-1. These values are significantly higher compared with those recorded for most adsorbents. In addition, the easily prepared Azo-CX8P can be reused at least six times without a loss of the adsorption efficiency, demonstrating its potential use in water purification.

Pillararene-Based Supramolecular Polymers for Adsorption and Separation

Supramolecular polymers have attracted increasing attention in recent years due to their perfect combination of supramolecular chemistry and traditional polymer chemistry. The design and synthesis of macrocycles have driven the rapid development of supramolecular chemistry and polymer science. Pillar[n]arenes, a new generation of macrocyclic compounds possessing unique pillar-shaped structures, nano-sized cavities, multi-functionalized groups, and excellent host-guest complexation abilities, are promising candidates to construct supramolecular polymer materials with enhanced properties and functionalities. This review summarizes recent progress in the design and synthesis of pillararene-based supramolecular polymers (PSPs) and illustrates their diverse applications as adsorption and separation materials. All performances are evaluated and analyzed in terms of efficiency, selectivity, and recyclability. Typically, PSPs can be categorized into three typical types according to their topologies, including linear, cross-linked, and hybrid structures. The advances made in the area of functional supramolecular polymeric adsorbents formed by new pillararene derivatives are also described in detail. Finally, the remaining challenges and future perspectives of PSPs for separation-based materials science are discussed. This review will inspire researchers in different fields and stimulate creative designs of supramolecular polymeric materials based on pillararenes and other macrocycles for effective adsorption and separation of a variety of targets.

Toward the Development of Simplified Lateral Flow Assays Using Hydrogels as the Universal Control Line

Lateral flow assays (LFA) have been widely utilized as point-of-care testing devices in diverse fields. However, it is imperative to preprint costly bioreceptors onto the lateral flow nitrocellulose membrane at the control line. The complex manufacturing process and relatively limited detection capabilities of LFA have impeded their utilization in more challenging fields. Here, we propose a novel and simple strategy to simplify the manufacture of LFA while simultaneously improving the sensitivity by modifying the hydrogel line (HL). In our study, it was observed that the sensitivity of commercial LFA strips could be enhanced by 2-5-fold by incorporating an extra HL. Particularly, a universal control line was developed to accommodate multiple LFA detection modes by substituting the conventional antibody control line with a hydrogel control line (HCL). As a proof of concept, the HCL performance could be associated with the slowdown and interception effect toward fluid, which are dependent on the permeation and hydrophilicity of the hydrogel with varying concentrations in the nitrocellulose membrane. This new design builds the foundation to enhance the sensitivity and develop the simplified LFA sensing platform without additional complicated processes.

Porous Cyclodextrin Polymer Enables Dendrite-Free and Ultra-Long Life Solid-State Zn-I2 Batteries

Zn-I2 batteries have attracted attention due to their low cost, safety, and environmental friendliness. However, their performance is still limited by the irreversible growth of Zn dendrites, hydrogen evolution reactions, corrosion, and shuttle effect of polyiodide. In this work, we have prepared a new porous polymer (CD-Si) by nucleophilic reaction of β-cyclodextrin with SiCl4 , and CD-Si is applied to the solid polymer electrolyte (denoted PEO/PVDF/CD-Si) to solve above-mentioned problems. Through the anchoring of the CD-Si, a conductive network with dual transmission channels was successfully constructed. Due to the non-covalent anchoring effect, the ionic conductivity of the solid polymer electrolytes (SPE) can reach 1.64×10-3  S cm-1 at 25 °C. The assembled symmetrical batteries can achieve highly reversible dendrite-free galvanizing/stripping (stable cycling for 7500 h at 5 mA cm-2 and 1200 h at 20 mA cm-2 ). The solid-state Zn-I2 battery shows an ultra-long life of over 35,000 cycles at 2 A g-1 . Molecular dynamics simulations are performed to elucidate the working mechanism of CD-Si in the polymer matrix. This work provides a novel strategy towards solid electrolytes for Zn-I2 batteries.

Porous organic polymers (POPs) for environmental remediation

Modern global industrialization along with the ever-increasing growth of the population has resulted in continuous enhancement in the discharge and accumulation of various toxic and hazardous chemicals in the environment. These harmful pollutants, including toxic gases, inorganic heavy metal ions, anthropogenic waste, persistent organic pollutants, toxic dyes, pharmaceuticals, volatile organic compounds, etc., are destroying the ecological balance of the environment. Therefore, systematic monitoring and effective remediation of these toxic pollutants either by adsorptive removal or by catalytic degradation are of great significance. From this viewpoint, porous organic polymers (POPs), being two- or three-dimensional polymeric materials, constructed from small organic molecules connected with rigid covalent bonds have come forth as a promising platform toward various leading applications, especially for efficient environmental remediation. Their unique chemical and structural features including high stability, tunable pore functionalization, and large surface area have boosted the transformation of POPs into various macro-physical forms such as thick and thin-film membranes, which led to a new direction in advanced level pollutant removal, separation and catalytic degradation. In this review, our focus is to highlight the recent progress and achievements in the strategic design, synthesis, architectural-engineering and applications of POPs and their composite materials toward environmental remediation. Several strategies to improve the adsorption efficiency and catalytic degradation performance along with the in-depth interaction mechanism of POP-based materials have been systematically summarized. In addition, evolution of POPs from regular powder form application to rapid and more efficient size and chemo-selective, "real-time" applicable membrane-based application has been further highlighted. Finally, we put forward our perspective on the challenges and opportunities of these materials toward real-world implementation and future prospects in next generation remediation technology.

Smart organic materials based on macrocycle hosts

Innovative design of smart organic materials is of great importance for the advancement of modern technology. Macrocycle hosts, possessing cyclic skeletons, intrinsic cavities, and specific guest binding properties, have demonstrated pronounced potential for the elaborate fabrication of a variety of functional organic materials with smart stimuli-responsive characteristics. In this tutorial review, we outline the current development of smart organic materials based on macrocycle hosts as key building blocks, focusing on the design principles and functional mechanisms of the tailored systems. Three main types of macrocycle-based smart organic materials are exemplified as follows according to the distinct forms of construction patterns: (1) supramolecular polymeric materials and nanoassemblies; (2) adaptive molecular crystals; (3) smart porous organic materials. The responsive performances of macrocycle-containing smart materials in versatile aspects, including mechanically adaptive polymers, soft optoelectronic devices, data encryption, drug delivery systems, artificial transmembrane channels, crystalline-state gas adsorption/separation, and fluorescence sensing, are illustrated by discussing the representative studies as paradigms, where the roles of macrocycles in these systems are highlighted. We also provide in the conclusion part the perspectives and remaining challenges in this burgeoning field.

Sulfonic acid functionalized monolithic column for high selectivity capillary electrochromatography separation

A new nano-scale spherical vinyl-functionalized covalent organic polymer (TAPT-DVA-COP) with uniform sizes around 300 nm was initially constructed using 2,5-divinyl-1,4-benzaldehyde (DVA) and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (TAPT) as monomers. Then, a sulfonic acid (-SO3H) modified COP termed COP-SO3H was developed based on post-sythesis method employing TAPT-DVA-COP as precursor. Capillary electrochromatography (CEC) monolithic columns were fabricated using the physical doping technique to exhibit the application potential of TAPT-DVA-COP and COP-SO3H. Compared to the TAPT-DVA-COP monolithic column, the COP-SO3H monolithic column achieved a highly selective separation between analytes with different properties, including monosubstituted benzenes, alkylbenzenes, hydroxybenzoates, nucleoside bases, and biogenic amines. Non-covalent interaction (NCI) analysis and experimental data show that the synergism of the sulfonic acid group and aromatic moieties on COP-SO3H endows the new stationary phase with diverse interactions, including ion exchange, hydrophobic, π-π and hydrogen bonding. In addition, the COP-SO3H monolithic column exhibited good reproducibility and excellent potential for the determination of hydroxybenzoates in compact powders and alkylbenzenes in effluent samples.

Azophenyl Calix[4]arene Porous Organic Polymer for Extraction and Analysis of Triphenylmethane Dyes from Seafood

Porous organic polymers (POPs) based on calix[4]arene with a hydrophobic π-rich cavity and host-guest recognition properties exhibit a wide application range of molecular extraction and separation. However, it is still a challenge to improve the extraction and separation selectivity by exploring and seeking appropriate building blocks for the functionalization and pore size adjustment of calix[4]arene. Herein, an azophenyl calix[4]arene porous organic polymer (AC-POP) was proposed. By introducing an electron-rich cavity and adjusting the pore sizes of calix[4]arene, the AC-POP showed high selectivity extraction performance in triphenylmethane (TPM) dyes. The extraction mechanism was explored by adsorption thermodynamics study, density functional theory (DFT) calculation, and reduced density gradient (RDG) and electrostatic potential (ESP) analyses, which suggested that the selectivity adsorption of TPM dyes based on AC-POP was mainly the result of entropy driven by the hydrophobic effect. In addition, the noncovalent interactions including π-π stacking, van der Waals force, and electrostatic interaction were also important factors affecting the adsorption capacity of TPM dyes. Under optimal extraction conditions, the AC-POP possessed a maximum extraction amount of 95.3 mg·g-1 for Rhodamine B (RB), high enrichment factor of about 100, and excellent reusability more than 10 times. Then, an analytical method of TPM dyes with AC-POP as a solid-phase extractant combined with high-performance liquid chromatography-ultraviolet (HPLC-UV) was established, which displayed excellent sensitivity with the limits of detection (LODs) and limits of quantitation (LOQs) in the ranges of 0.004-0.35 and 0.016-1.16, respectively. The mean recoveries for TPM dyes ranged from 85.0 to 109.4% with an RSD of 0.48-9.45%. The proposed method was successfully applied to the analysis of the five TPM dyes in seafood matrix samples.

Novel Biocompatible Trianglamine Networks for Efficient Iodine Capture

Herein, we report for the first time a biocompatible cross-linked trianglamine (Δ) network for the efficient iodine removal from the vapor phase, water, and seawater. In the vapor phase, the cross-linked network could capture 6 g g-1 of iodine, ranking among the most performant materials for iodine vapor capture. In the liquid phase, this cross-linked network is also capable of capturing iodine at high rates from aqueous media (water and seawater). This network displayed fast adsorption kinetics, and they are fully recyclable. This study reveals the high affinity of iodine for the intrinsic cavity of the trianglamine. The synthesized materials are extremely interesting since they are environmentally friendly and inexpensive and the synthesis could easily be scaled up to be used as the material of choice in response to accidents in the nuclear industry.

Eutectic Molten Salt Synthesis of Highly Microporous Macrocyclic Porous Organic Polymers for CO2 Capture

The development of porous materials is of great interest for the capture of CO2 from various emission sources, which is essential to mitigate its detrimental environmental impact. In this direction, porous organic polymers (POPs) have emerged as prime candidates owing to their structural tunability, physiochemical stability and high surface areas. In an effort to transfer an intrinsic property of a cyclotetrabenzoin‐derived macrocycle – its high CO2 affinity – into porous networks, herein we report the synthesis of three‐dimensional (3D) macrocycle‐based POPs through the polycondensation of an octaketone macrocycle with phenazine‐2,3,7,8‐tetraamine hydrochloride. This polycondensation was performed under ionothermal conditions, using a eutectic salt mixture in the temperature range of 200 to 300 °C. The resulting polymers, named 3D‐mmPOPs, showed reaction temperature‐dependent surface areas and gas uptake properties. 3D‐mmPOP‐250 synthesized at 250 °C exhibited a surface area of 752 m2 g−1 and high microporosity originating from the macrocyclic units, thus resulting in an excellent CO2 binding enthalpy of 40.6 kJ mol−1 and CO2 uptake capacity of 3.51 mmol g−1 at 273 K, 1.1 bar.

Sulfonated polyhedral oligomeric silsesquioxane-cyclodextrin hybrid polymers for efficient removal of micropollutants from water

Herein, β-cyclodextrin-containing hybrid polymers (P1, P2 and P3) were prepared through crosslinking partially benzylated β-cyclodextrin (PBCD) by octavinylsilsesquioxane (OVS). P1 stood out in screening studies and the residual hydroxyl groups of PBCD was sulfonate-functionalized. The obtained P1-SO₃Na showed greatly enhanced adsorption towards cationic MPs and maintained the excellent adsorption performance towards neutral MPs. The rate constants (k₂) of cationic MPs upon P1-SO₃Na were 9.8-34.8 times larger than those upon P1. The equilibrium uptakes of the neutral and cationic MPs upon P1-SO₃Na were above 94.5 %. Meanwhile, P1-SO₃Na demonstrated appreciable adsorption capacities, excellent selectivity, effective adsorption of mixed MPs at environmental levels and good reusability. These results confirmed the great potential of P1-SO₃Na as effective adsorbent to remove MPs from water.

Rationalizing the formation of porosity in mechanochemically-synthesized polymers

In this study, we present a matrix of 144 mechanochemically-synthesized polymers. All polymers were constructed by the solvent-free Friedel-Crafts polymerization approach, employing 16 aryl-containing monomers and 9 halide-containing linkers, which were processed in a high-speed ball mill. This Polymer Matrix was utilized to investigate the origin of porosity in Friedel-Crafts polymerizations in detail. By examining the physical state, molecular size, geometry, flexibility, and electronic structure of the utilized monomers and linkers, we identified the most important factors influencing the formation of porous polymers. We analyzed the significance of these factors for both monomers and linkers based on the yield and specific surface area of the generated polymers. Our in-depth evaluation serves as a benchmark study for future targeted design of porous polymers by the facile and sustainable concept of mechanochemistry.

Design and Synthesis of Porous Organic Polymers: Promising Catalysts for Lignocellulose Conversion to 5-Hydroxymethylfurfural and Derivates

In the face of the current energy and environmental problems, the full use of biomass resources instead of fossil energy to produce a series of high-value chemicals has great application prospects. 5-hydroxymethylfurfural (HMF), which can be synthesized from lignocellulose as a raw material, is an important biological platform molecule. Its preparation and the catalytic oxidation of subsequent products have important research significance and practical value. In the actual production process, porous organic polymer (POP) catalysts are highly suitable for biomass catalytic conversion due to their high efficiency, low cost, good designability, and environmentally friendly features. Here, we briefly describe the application of various types of POPs (including COFs, PAFs, HCPs, and CMPs) in the preparation and catalytic conversion of HMF from lignocellulosic biomass and analyze the influence of the structural properties of catalysts on the catalytic performance. Finally, we summarize some challenges that POPs catalysts face in biomass catalytic conversion and prospect the important research directions in the future. This review provides valuable references for the efficient conversion of biomass resources into high-value chemicals in practical applications.

Review on Isatin- A Remarkable Scaffold for Designing Potential Therapeutic Complexes and Its Macrocyclic Complexes with Transition Metals

Role of synthetic coordination chemistry in pharmaceutical science is expeditiously increased due to its sundry relevances in this field. The present review endows the synthesized macrocyclic complexes of transition metal ions containing isatin and its derivatives as ligand precursors, their characterization and their copious pharmaceutical applications. Isatin (1H-Indole-2,3-dione) is a protean compound (presence of lactam and keto moiety permits to change its molecular framework) that can be obtained from marine animals, plants, and is also found in mammalian tissues and in human fluids as a metabolite of amino acids. It can be used for the synthesis of miscellaneous organic and inorganic complexes and for designing of drugs since it has remarkable utility in pharmaceutical industry due to its wide range of biological and pharmacological activities, for instance anti-microbial, anti-HIV, anti-tubercular, anti-cancer, anti-viral, anti-oxidant, anti-inflammatory, anti-angiogenic, analgesic activity, anti-Parkinson's disease, anti-convulsant etc. This review provides extensive information about the latest methods for the synthesis of isatin or its substituted derivatives based macrocyclic complexes of transition metals and their plentiful applications in medicinal chemistry.

Graphical Abstract

Macrocycle-Based Covalent Organic Frameworks

Macrocycles with well-defined cavities and the ability to undergo supramolecular interactions are classical materials that have played an essential role in materials science. However, one of the most substantial barriers limiting the utilization of macrocycles is their aggregation, which blocks the active regions. Among many attempted strategies to prevent such aggregation, installing macrocycles into covalent organic frameworks (COFs), which are porous and stable reticular networks, has emerged as an ideal solution. The resulting macrocycle-based COFs (M-COFs) preserve the macrocycles' unique activities, enabling applications in various fields such as single-atom catalysis, adsorption/separation, optoelectronics, phototherapy, and structural design of forming single-layered or mechanically interlocked COFs. The resulting properties are unmatchable by any combination of macrocycles with other substrates, opening a new chapter in advanced materials. This review focuses on the latest progress in the concepts, synthesis, properties, and applications of M-COFs, and presents an in-depth outlook on the challenges and opportunities in this emerging field.

Precise Manipulation of Excited-State Intramolecular Proton Transfer via Incorporating Charge Transfer toward High-Performance Film-Based Fluorescence Sensing

Excited-state intramolecular proton transfer (ESIPT) has been widely employed for the design of a variety of functionality-led molecular systems. However, precise manipulation of the excited-state reaction is challenging. Herein, we report a new tactic for tuning ESIPT via incorporating an excited-state intramolecular charge transfer (ESICT) process. Specifically, three o-carborane derivatives, NaCBO, PaCBO, and PyCBO, were designed, where the 2-(2'-hydroxyphenyl)-benzothiazole is a typical ESIPT unit functioning as an electron acceptor, and the electron-donating units are naphthyl-(Na), phenanthrenyl-(Pa), and pyrenyl-(Py), respectively. The architectures of the molecules are featured with a face-to-face alignment of the two units. Spectroscopy and theoretical calculation studies revealed that the electron-donating capacity of the donors and solvent polarity continuously modulate the ESIPT/ESICT energetics and dynamics, resulting in distinct emissions. Moreover, the molecules depicted not only highly porous structures but also very different fluorescent colors in the solid state, enabling highly selective film-based fluorescence sensing of mustard gas simulant, 2-chloroethyl ethyl sulfide, with a detection limit of 50 ppb and a response time of 5 s. This work thus provides a reliable strategy for the creation of high-performance sensing fluorophores via ESIPT manipulation.

Biodegradable porous polymeric drug as a drug delivery system: alleviation of doxorubicin-induced cardiotoxicity via passive targeted release

Doxorubicin (DOX) is an effective chemotherapeutic drug developed against a broad range of cancers, and its clinical applications are greatly restricted by the side effects of severe cardiotoxicity during tumour treatment. Herein, the DOX-loaded biodegradable porous polymeric drug, namely, Fc-Ma-DOX, which was stable in the circulation, but easy to compose in the acidic medium, was used as the drug delivery system avoiding the indiscriminate release of DOX. Fc-Ma was constructed via the copolymerization of 1,1'-ferrocenecarbaldehyde with d-mannitol (Ma) through the pH-sensitive acetal bonds. Echocardiography, biochemical parameters, pathological examination, and western blot results showed that DOX treatment caused increased myocardial injury and oxidative stress damage. In contrast, treatment with Fc-Ma-DOX significantly reduced myocardial injury and oxidative stress by DOX treatment. Notably, in the Fc-Ma-DOX treatment group, we observed a significant decrease in the uptake of DOX by H9C2 cells and a significant decrease in reactive oxygen species (ROS) production.

Pillararene-Based Supramolecular Polymers for Cancer Therapy

Supramolecular polymers have attracted considerable interest due to their intriguing features and functions. The dynamic reversibility of noncovalent interactions endows supramolecular polymers with tunable physicochemical properties, self-healing, and externally stimulated responses. Among them, pillararene-based supramolecular polymers show great potential for biomedical applications due to their fascinating host-guest interactions and easy modification. Herein, we summarize the state of the art of pillararene-based supramolecular polymers for cancer therapy and illustrate its developmental trend and future perspective.

Polymerization boosting cascade energy transfer based on opened glucopyranosyl β-cyclodextrin

An injectable polysaccharide supramolecular hydrogel was successfully fabricated from opened D-glucopyranosyl β-cyclodextrin with four aldehyde groups (ACD) cross-linked with biomacromolecule chitosan (CS), which was not only beneficial to the clustering-triggered emission of CS with high quantum yield (32.25%), but also could co-assemble with a first stage acceptor triphenylamine derivative (TPA) and encapsulate Cyanine 5 (Cy5) or Nile blue (NiB) achieving supramolecular cascade energy transfer from the cross-linked polymer to the dyes, leading to fluorescence emission at 673 nm or 680 nm, and could be further applied in cell imaging.