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Elastomers are widely used in various fields owing to their excellent tensile properties. Recyclable and self-healing properties are key to extending the service life of elastomers. Accumulating evidence indicates that dynamic covalent chemistry has emerged as a powerful tool for constructing recyclable and self-healing materials. In this work, we demonstrate the preparation of a recyclable and self-healable polydimethylsiloxane (PDMS) elastomer based on the Knoevenagel condensation (KC) reaction. This PDMS elastomer was prepared by the KC reaction catalyzed by 4-dimethylaminopyridine (DMAP). The obtained PDMS elastomer exhibited an elongation at break of 266%, a tensile strength of 0.57 MPa, and a good thermal stability (Td=357 °C). In addition, because of the presence of dynamic C = C bonds formed by the KC reaction and low glass transition temperature (Tg=−117 °C). This PDMS exhibited good self-healing and recycling properties at room temperature and could be reprocessed by hot pressing. In addition, the PDMS elastomer exhibits good application prospects in the fields of adhesives and flexible electronic devices. [ABSTRACT FROM AUTHOR]

The development of more energy‐efficient separation technologies is essential. Especially the separation of cyclic aliphatic hydrocarbons from their aromatic counterparts remains a significant challenge due to azeotrope formation and similar physical properties, often requiring energy‐intensive processes. Herein, we introduce a novel class of electron‐deficient macrocycles with a unique rectangular structure to optimise interactions within the pore, enabling the highly selective molecular sieving of aromatic compounds from mixtures. Utilising dynamic covalent imine chemistry, the squareimine NDI2F42‐based crystalline functional material is directly obtained from the reaction mixture in a single self‐assembly step in high yields of 83 %, alongside the larger NDI2F82 congener, which can be obtained in 69 % yield. In vapour sorption and diffusion experiments, NDI2F42 demonstrates rapid adsorption kinetics with selectivities of 97 : 3 for benzene over cyclohexane and 93 : 7 for toluene over methylcyclohexane, while single‐crystal and powder X‐ray diffraction studies indicate that the selectivity is primarily governed by directed interactions between the electron‐deficient panels and aromatic guests. [ABSTRACT FROM AUTHOR]

AbstractDynamic covalent macromolecular networks represent a groundbreaking advancement in adaptive drug delivery systems, enabling precise and controlled drug release in response to various physiological stimuli. These systems rely on dynamic covalent bonds, such as imine, disulfide and boronic ester linkages, which are capable of reversible bond exchange. The ability of these bonds to respond to environmental triggers like pH, temperature, light and redox conditions, makes them highly adaptable for tailored drug release. This review explores the fundamentals of dynamic covalent chemistry and the design and synthesis of macromolecular networks, highlighting their ability to integrate diverse stimuli-responsiveness. Key applications in targeted cancer therapy, smart hydrogels for wound healing, co-delivery of therapeutics and long-term controlled drug release are discussed. These systems are also finding a place in tissue engineering, where adaptive drug release can be synchronized with tissue regeneration. Despite the numerous advantages of dynamic covalent macromolecular networks, challenges remain regarding their scalability, biocompatibility and long-term stability. Overall, dynamic covalent networks hold great potential to revolutionize the field of drug delivery by offering enhanced control, specificity and therapeutic efficacy in complex medical treatments, such as cancer and chronic disease management. [ABSTRACT FROM AUTHOR]

Thiol‐disulfide interchange has been a large field of study for both biochemists and physical organic chemists alike due to its prevalence within biological systems and fundamentally interesting dynamic nature. More recently, efforts have been made to harness the power of this reversible reaction to make self‐assembling systems of macrocyclic molecules. However, less effort has focused on the fundamental work of isolating these assemblies and studying the factors that control the assembly and sorting of these emerging cyclic systems. A more complete fundamental understanding of factors controlling such self‐assembly could also improve understanding of the complex systems biology of thiol exchange while also aiding in the design of dynamic thiol assembly to enable applications ranging from drug delivery and biosensing to new materials synthesis. We have shown previously that pnictogen‐assisted self‐assembly enables formation of discrete disulfide macrocycles and cages without competition from polymer formation for a wide variety of alkyl thiols. In this study, we report the expansion of pnictogen‐assisted self‐assembly methods to form disulfide bearing macrocycles from aryl thiol containing ligands, allowing access to previously unreported molecules. These studies complement classical physical organic and chemical biology studies on the rates and products of aryl thiol oxidation to disulfides, and we show that this self‐assembly method revises some prevailing wisdom from these key classical studies by providing new product distributions and new isolable products in cyclic disulfide formation. [ABSTRACT FROM AUTHOR]

Mechanical metamaterials achieve unprecedented mechanical properties through their periodically interconnected unit cell structure. However, their geometrical design and resulting mechanical properties are typically fixed during fabrication. Despite efforts to implement covalent adaptable networks (CANs) into metamaterials for permanent shape reconfigurability, emphasis is given to global rather than local shape reconfiguration. Furthermore, the change of effective material properties like Poisson's ratio remains to be explored. In this work, a non‐isocyanate polyurethane elastomeric CAN, which can be thermally reconfigured, is introduced into a metamaterial architecture. Structural reconfiguration allows for the local and global reprogramming of the Poisson's ratio with change of unit cell angle from 60° to 90° for the auxetic and 120° to 90° for the honeycomb metamaterial. The respective Poisson's ratio changes from −1.4 up to −0.4 for the auxetic and from +0.7 to +0.2 for the honeycomb metamaterial. Carbon nanotubes are deposited on the metamaterials to enable global and spatial electrothermal heating for on‐demand reshaping with a heterogeneous Poisson's ratio ranging from −2 to ≈0 for a single auxetic or +0.6 to ≈0 for a single honeycomb metamaterial. Finite element simulations reveal how permanent geometrical reconfiguration results from locally and globally relaxed heated patterns. [ABSTRACT FROM AUTHOR]

The in situ monitoring of dynamic covalent macromolecular boronate esters represents a difficult task. In this report, we present an in situ method using fluoride coordination and 11B NMR spectroscopy to determine the amount of boronate esters in a mixture of boronic acids and cis-diols. With fluoride coordination, the boronic acid and boronate esters afforded trifluoroborate and fluoroboronate esters, giving identical resonances at 3 and 9 ppm in the 11B NMR spectra. The same titration did not alter the resonance of amine-coordinated boronate esters, which gave resonances of 14 ppm in the 11B NMR spectra. Therefore, boronic acids, boronate esters, and amine-coordinated boronate esters gave three identical resonances, and the ratio of each component was obtained by deconvolution for a further equilibrium analysis. This method monitored the conversion among three species in various conditions, including separation. Accordingly, boronate esters were more stable after precipitation than chromatography, in which 29% and 20% of boronate esters were lost after purification. This method was applied to study the reaction between the boronic acid-decorated defect lysine dendron (16) and dopamine. No boronic acid signal was observed after adding 1 equivalent of dopamine; no boronic acid signal was observed in the NMR spectrum. According to the spectrum, the product contains 65% boronate ester and 35% N–B-coordinated derivatives. This method helps identify the presence of the three intermediates and provides more insights into this reaction. [ABSTRACT FROM AUTHOR]

The remarkable advantages and promising application potentials of aggregation‐induced emission (AIE) materials have seen significant advancements in recent years. Notably, AIE materials incorporating dynamic covalent bonds (DCBs) have garnered escalating attention and demonstrated remarkable progress due to their reversible and self‐adaptive properties, thus exhibiting immense potential across various domains including biomedicine, nanomaterials, sensing, and optical displays. This review aims to provide a comprehensive overview of the recent strides in DCBs‐based AIE materials, organized by the types of dynamic covalent bonds utilized, such as Diels–Alder reaction, imine bond, transesterification, boronic ester bond, disulfide bond, [2+2] Cycloaddition Reaction and X‐yne adducts exchange. Through exemplifying representative cases, we elucidate the design principles of chemical structures and the diverse dynamic behaviors exhibited by DCBs‐based AIE materials. Leveraging the principles of dynamic covalent chemistry, these emissive materials can be facilely prepared, and they possess inherent self‐adaptability and responsiveness to stimuli. Finally, we present succinct conclusions and discuss future trends in this burgeoning field, offering fresh insights into the design of novel luminescent materials based on dynamic covalent bonds for broader applications. [ABSTRACT FROM AUTHOR]

Nanoparticle surfactants (NPSs) that form via the reversible non‐covalent interactions between nanoparticles (NPs) and polymer ligands at the oil‐water interface have received great attention in constructing structured liquids with unique stimuli‐responsiveness. Introducing dynamic covalent interactions to generate NPSs is expected to achieve a balance between high mechanical strength and dynamic responsiveness of the interfacial assemblies. Here, we present the formation, assembly, and jamming of a new type of NPS by the co‐assembly between polydopamine NPs (PDA NPs) and poly(styrene‐co‐methacrylamidophenylboronic acid) at the oil‐water interface. Dynamic covalent boronate ester bonds form in situ at the interface and show multiple responsiveness when applying stimuli such as pH, H2O2, and temperature, allowing the controlled assembly/jamming of NPSs and reconfiguration of liquid constructs. Due to the photothermal property of PDA NPs, the temperature responsiveness of boronate ester bonds can also be triggered by irradiating the biphasic system with near‐infrared (NIR) light. Moreover, when bringing two droplets encapsulated with NPSs into contact and irradiating the contact area by NIR, thermal welding of droplets can be realized, offering a straightforward to construct droplet networks and modular liquid devices. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) are known to be a promising class of materials for a wide range of applications, yet their poor solution processability limits their utility in many areas. Here we report a pore engineering method using hydrophilic side chains to improve the processability of hydrazone and β-ketoenamine-linked COFs and the production of flexible, crystalline films. Mechanical measurements of the free-standing COF films of COF-PEO-3 (hydrazone-linked) and TFP-PEO-3 (β-ketoenamine-linked), revealed a Young's modulus of 391.7 MPa and 1034.7 MPa, respectively. The solubility and excellent mechanical properties enabled the use of these COFs in dielectric devices. Specifically, the TFP-PEO-3 film-based dielectric capacitors display simultaneously high dielectric constant and breakdown strength, resulting in a discharged energy density of 11.22 J cm-3 . This work offers a general approach for producing solution processable COFs and mechanically flexible COF-based films, which hold great potential for use in energy storage and flexible electronics applications.

Dynamic covalent chemistry (DCC) has revolutionized the field of polymer science by offering new opportunities for the synthesis, processability, and recyclability of polymers as well as in the development of new materials with interesting properties such as vitrimers and covalent organic frameworks (COFs). Many DCC linkages have been explored for this purpose, but recently, enamine‐ones have proven to be promising dynamic linkages because of their facile reversible transamination reactions under thermodynamic control. Their high stability, stimuli‐responsive properties, and tunable kinetics make them promising dynamic cross‐linkers in network polymers. Given the rapid developments in the field in recent years, this review provides a critical and up‐to‐date overview of recent developments in enamine‐one chemistry, including factors that control their dynamics. The focus of the review will be on the utility of enamine‐ones in designing a variety of processable and self‐healable polymers with important applications in vitrimers and recyclable closed‐loop polymers. The use of enamine‐one linkages in crystalline polymers, known as COFs and their applications are also summarized. Finally, we provide an outlook for future developments in this field. [ABSTRACT FROM AUTHOR]

This work reports the synthesis and self‐assembly of perylene diimide (PDI)‐containing macrocycles designed for facile and high‐throughput production of shape‐persistent, macrocyclic organic electronic materials. Specifically, utilizing dynamic covalent chemistry (DCvC), this work showcases ditopic thiols can be utilized as building blocks toward 3D materials with defined porosity, low‐lying unoccupied molecular orbitals, and intrinsic fluorescence. The PDI disulfide‐linked macrocycles are generated in a single step from the thiolic building block to yield dimeric through pentameric assemblies in overall 95% combined yield; moreover, following self‐assembly, the disulfide ensemble is sulfur extruded to the more kinetically stable thioether in 79% combined yield. The modular design suggests these methods can be used to easily self‐assemble other electronically active precursors for utility in porous macrocyclic materials where stepwise pathways may be laborious and/or low yielding. [ABSTRACT FROM AUTHOR]

Catalyst‐free, radical‐based reactive processing is used to transform low‐density polyethylene (LDPE) into polyethylene covalent adaptable networks (PE CANs) using a dialkylamino disulfide crosslinker, BiTEMPS methacrylate (BTMA). Two versions of BTMA are used, BTMA‐S2, with nearly exclusively disulfide bridges, and BTMA‐Sn, with a mixture of oligosulfide bridges, to produce S2 PE CAN and Sn PE CAN, respectively. The two PE CANs exhibit identical crosslink densities, but the S2 PE CAN manifests faster stress relaxation, with average relaxation times ∼4.5 times shorter than those of Sn PE CAN over a 130 to 160 °C temperature range. The more rapid dynamics of the S2 PE CAN translate into a shorter compression‐molding reprocessing time at 160 °C of only 5 min (vs 30 min for the Sn PE CAN) to achieve full recovery of crosslink density. Both PE CANs are melt‐extrudable and exhibit full recovery within experimental uncertainty of crosslink density after extrusion. Both PE CANs are self‐healable, with a crack fully repaired and the original tensile properties restored after 30 min for the S2 PE CAN or 60 min for the Sn PE CAN at a temperature slightly above the LDPE melting point and without the assistance of external forces. [ABSTRACT FROM AUTHOR]

The overwhelming majority of artificial chemical reaction networks respond to stimuli by relaxing towards an equilibrium state. The opposite response—moving away from equilibrium—can afford the endergonic synthesis of molecules, of which only rare examples have been reported. Here, we report six examples of Diels–Alder adducts formed in an endergonic process and use this strategy to realize their stepwise accumulation. Indeed, systems respond to repeated occurrences of the same stimulus by increasing the amount of adduct formed, with the final network distribution depending on the number of stimuli received. Our findings indicate how endergonic processes can contribute to the transition from responsive to adaptive systems. [ABSTRACT FROM AUTHOR]

Cellulose nanocrystal (CNC)‐reinforced composites are gaining commercial attention on account of their high strength and sustainable sourcing. Grafting polymers to the CNCs in these composites has the potential to improve their properties, but current solution‐based synthesis methods limit their production at scale. Utilizing dynamic hindered urea chemistry, a new method for the melt‐functionalization of cellulose nanocrystals has been developed. This method does not require toxic solvents during the grafting step and can achieve grafting densities competitive with state‐of‐the‐art solution‐based grafting methods. Using cotton‐sourced, TEMPO‐oxidized CNCs, multiple molecular weights of poly(ethylene glycol) (PEG) as well as dodecane, polycaprolactone, and poly(butyl acrylate) were grafted to the CNC surface. With PEG‐grafted nanoparticles, grafting densities of 0.47 chains nm−2 and 0.10 chains nm−2 were achieved with 2000 and 10,000 g mol−1 polymer chains respectively, both of which represent significant improvements over previous reports for solution‐based PEG grafting onto CNCs. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) have emerged as versatile materials with many applications, such as carbon capture, molecular separation, catalysis, and energy storage. Traditionally, flexible building blocks have been avoided due to their potential to disrupt ordered structures. Recent studies have demonstrated the intriguing properties and enhanced structural diversity achievable with flexible components by judicious selection of building blocks. This study presents a novel series of ionic COFs (ICOFs) consisting of tetraborate nodes and flexible linkers. These ICOFs use borohydrides to irreversibly deprotonate the alcohol monomers to achieve a high degree of polymerization. Structural analysis confirms the dia topologies. Reticulation is explored using various monomers and metal counterions. Also, these frameworks exhibit excellent stability in alcohols and coordinating solvents. The materials have been tested as single‐ion conductive solid‐state electrolytes. ICOF‐203‐Li displays one of the lowest activation energies reported for ion conduction. This tetraborate chemistry is anticipated to facilitate further structural diversity and functionality in crystalline polymers. [ABSTRACT FROM AUTHOR]

The emergence of covalent adaptable networks (CANs) based on dynamic covalent bonds (DCBs) presents a promising avenue for achieving resource recovery and utilization. In this study, we discovered a dynamic covalent bond called selenacetal, which is obtained through a double click reaction between selenol and activated alkynes. Density functional theory (DFT) calculations demonstrated that the ΔG for the formation of selenoacetals ranges from 12 to 18 kJ mol−1, suggesting its potential for dynamic reversibility. Dynamic exchange experiments involving small molecules and polymers provide substantial evidence supporting the dynamic exchange properties of selenoacetals. By utilizing this highly efficient click reaction, we successfully synthesized dynamic materials based on selenoacetal with remarkable reprocessing capabilities without any catalysts. These materials exhibit chemical recycling under alkaline conditions, wherein selenoacetal (SA) can decompose into active enone selenide (ES) and diselenides. Reintroducing selenol initiates a renewed reaction with the enone selenide, facilitating material recycling and yielding a newly developed dynamic material exhibiting both photo‐ and thermal responsiveness. The results underscore the potential of selenoacetal polymers in terms of recyclability and selective degradation, making them a valuable addition to conventional covalent adaptable networks. [ABSTRACT FROM AUTHOR]

Organic radicals based dynamic covalent chemistry is promising in preparing stimuli‐responsive chromic materials, due to their simplicity of dissociation/association, accompanied with distinct color changes during the process. However, suitable organic radicals for dynamic covalent chemistry have not been widely explored yet. Herein, a series of oxindolyl‐based mono‐radicals (OxRs) with different substituents were successfully synthesized and studied systematically as potential building blocks for stimuli‐responsive chromic materials. These OxRs would dimerize spontaneously to form their corresponding dimers. The structures of dimers were unambiguously confirmed through low‐temperature 1H NMR and single‐crystal X‐ray diffraction analyses. Dynamic interconversion between monomers and dimers was achieved by reversible cleavage and recovery of the σ‐bond upon soft external stimuli (temperature, pressure, and solvent polarity), accompanied by significant color changes. It is interesting that the stability of the mono‐radical could be tuned through changing different substituents, and consequently altering the bond dissociation energy of the dynamic covalent bond between monomers. These new OxRs characterized by appreciable properties are entitled to more opportunities in developing mechanochromic and thermochromic materials, where their responsiveness to stimuli can be readily controlled by the substituents adhered. [ABSTRACT FROM AUTHOR]

Abstract Nanoparticle surfactants (NPSs) that form via the reversible non‐covalent interactions between nanoparticles (NPs) and polymer ligands at the oil‐water interface have received great attention in constructing structured liquids with unique stimuli‐responsiveness. Introducing dynamic covalent interactions to generate NPSs is expected to achieve a balance between high mechanical strength and dynamic responsiveness of the interfacial assemblies. Here, we present the formation, assembly, and jamming of a new type of NPS by the co‐assembly between polydopamine NPs (PDA NPs) and poly(styrene‐co‐methacrylamidophenylboronic acid) at the oil‐water interface. Dynamic covalent boronate ester bonds form in situ at the interface and show multiple responsiveness when applying stimuli such as pH, H2O2, and temperature, allowing the controlled assembly/jamming of NPSs and reconfiguration of liquid constructs. Due to the photothermal property of PDA NPs, the temperature responsiveness of boronate ester bonds can also be triggered by irradiating the biphasic system with near‐infrared (NIR) light. Moreover, when bringing two droplets encapsulated with NPSs into contact and irradiating the contact area by NIR, thermal welding of droplets can be realized, offering a straightforward to construct droplet networks and modular liquid devices.

Abstract The remarkable advantages and promising application potentials of aggregation‐induced emission (AIE) materials have seen significant advancements in recent years. Notably, AIE materials incorporating dynamic covalent bonds (DCBs) have garnered escalating attention and demonstrated remarkable progress due to their reversible and self‐adaptive properties, thus exhibiting immense potential across various domains including biomedicine, nanomaterials, sensing, and optical displays. This review aims to provide a comprehensive overview of the recent strides in DCBs‐based AIE materials, organized by the types of dynamic covalent bonds utilized, such as Diels–Alder reaction, imine bond, transesterification, boronic ester bond, disulfide bond, [2+2] Cycloaddition Reaction and X‐yne adducts exchange. Through exemplifying representative cases, we elucidate the design principles of chemical structures and the diverse dynamic behaviors exhibited by DCBs‐based AIE materials. Leveraging the principles of dynamic covalent chemistry, these emissive materials can be facilely prepared, and they possess inherent self‐adaptability and responsiveness to stimuli. Finally, we present succinct conclusions and discuss future trends in this burgeoning field, offering fresh insights into the design of novel luminescent materials based on dynamic covalent bonds for broader applications.

Depot‐type drug delivery systems are designed to deliver drugs at an effective rate over an extended period. Minimizing initial "burst" can also be important, especially with drugs causing systemic toxicity. Both goals are challenging with small hydrophilic molecules. The delivery of molecules such as the ultrapotent local anesthetic tetrodotoxin (TTX) exemplifies both challenges. Toxicity can be mitigated by conjugating TTX to polymers with ester bonds, but the slow ester hydrolysis can result in subtherapeutic TTX release. Here, we developed a prodrug strategy, based on dynamic covalent chemistry utilizing a reversible reaction between the diol TTX and phenylboronic acids. These polymeric prodrugs exhibited TTX encapsulation efficiencies exceeding 90 % and the resulting polymeric nanoparticles showed a range of TTX release rates. In vivo injection of the TTX polymeric prodrugs at the sciatic nerve reduced TTX systemic toxicity and produced nerve block lasting 9.7±2.0 h, in comparison to 1.6±0.6 h from free TTX. This approach could also be used to co‐deliver the diol dexamethasone, which prolonged nerve block to 21.8±5.1 h. This work emphasized the usefulness of dynamic covalent chemistry for depot‐type drug delivery systems with slow and effective drug release kinetics. [ABSTRACT FROM AUTHOR]

We report the synthesis of arsenic heterocycles derived from saccharides 2–4 and AsCl3. Compounds 5 and 6 are stable in aqueous solutions, DMSO, or methanolic solutions. However, NMR and HPLC studies revealed that intramolecular trans‐esterification processes leads to dynamic equilibria. Theoretical studies revealed that three arsenates and two arsoranes participate in these intramolecular equilibria and account for the experimental spectroscopy and HPLC results. Through the correlation between the experimental and theoretical 13C NMR spectra, we proposed the speciation of arsenic Compounds 5 and 6. Moreover, experimental and theoretical IR spectra demonstrated that arsenates 5 A and 6 A predominate in the solid state. QTAIM studies were performed to explain the chemical shifts in the 13C NMR spectra. Biological studies suggest that the structural flexibility of Compounds 5 and 6 increase the cytotoxic and antiproliferative activities of these compounds. [ABSTRACT FROM AUTHOR]

Multiple dynamic libraries of compounds are generated when more than one reversible reaction comes into play. Commonly, two or more orthogonal reversible reactions are used, leading to non‐communicating dynamic libraries which share no building blocks. Only a few examples of communicating libraries have been reported, and in all those cases, building blocks are reversibly exchanged from one library to the other, constituting an antiparallel dynamic covalent system. Herein we report that communication between two different dynamic libraries through an irreversible process is also possible. Indeed, alkyl amines cancel the dynamic regime on the nucleophilic substitution of tetrazines, generating kinetically inert compounds. Interestingly, such amine can be part of another dynamic library, an imine‐amine exchange. Thus, both libraries are interconnected with each other by an irreversible process which leads to kinetically inert structures that contain parts from both libraries, causing a collapse of the complexity. Additionally, a latent irreversible intercommunication could be developed. In such a way, a stable molecular system with specific host–guest and fluorescence properties, could be irreversibly transformed when the right stimulus was applied, triggering the cancellation of the original supramolecular and luminescent properties and the emergence of new ones. [ABSTRACT FROM AUTHOR]

A well‐behaved dynamic library composed of two imines and corresponding amines was subjected to the action of an activated carboxylic acid (ACA), whose decarboxylation is known to be base promoted, in different solvents, namely CD2Cl2, CD3CN, and mixtures of them. Two non‐equilibrium systems are consequently obtained: i) a dissipative (CD2Cl2) and ii) an out‐of‐equilibrium (CD3CN) dynamic library whose composition goes back to equilibrium after a given time. In the former case, the library is fully coupled with the decarboxylation of the ACA, while in the latter, an energy ratchet operates. In the mixed solvents, the library exhibits a mediated behavior. Interestingly, in the presence of an excess of added ACA, the different behavior of the imine library in the two solvents is expected to manifest only when the excess acid is consumed. [ABSTRACT FROM AUTHOR]

Shape‐persistent organic cages are an intriguing class of molecular porous materials. Through hierarchical molecular design, size and shape of the intrinsic molecular voids are controlled by dynamic covalent chemistry, while pore structure and topology are governed by noncovalent alignment in the solid state. However, the predictable and reliable crystallization of organic cages is still challenging since long‐range superstructures are solely based on weak and rather unidirectional supramolecular interactions. In this tutorial review, we provide a general classification of porous solid‐state materials and discuss specific design principles regarding the dynamic covalent reactions, the small‐molecule building blocks and solid‐state engineering. Furthermore, we introduce the most important analytical techniques for porous materials with a special focus on organic cages. [ABSTRACT FROM AUTHOR]

The dynamic nature of calamitic liquid crystals is exploited to perform isothermal phase transitions driven by dynamic covalent chemistry. For this purpose, nematic (N) arrays based on aldehyde 1 were treated with different amines (A–E) in an on‐surface process, which resulted in different isothermal phase transitions. These phase transformations were caused by in situ imination reactions and are dependent on the nature of the added amine. Transitions from the N to crystal (1A, 1E), isotropic (1B), and smectic (Sm) (1C, 1D) phases were achieved, while the resulting materials feature thermotropic liquid crystal behavior. A sequential transformation from the N 1 to the Sm 1C and then to the N 1B was achieved by coupling an imination to a transimination processes and adjusting the temperature. All of these processes were well characterized by microscopic, spectroscopic, and X‐ray techniques, unlocking not only the constitutional but also the structural aspects of the phase transitions. This work provides new insights into designing constitutionally and structurally adaptable liquid crystal systems, paving the way toward the conception of programable evolutive pathways and adaptive materials. [ABSTRACT FROM AUTHOR]

The loss of function after prolonged periods of use is inevitable for all materials including plastics. Hence, self‐healing capabilities are a key development to prolong the service lifetime of materials. One of such self‐healing capabilities can be achieved by integrating dynamic bonds such as boronic ester linkages into polymeric materials, however the rate of self‐healing in these materials is insufficient and current methods to accelerate it are limited. In this study, we report the rational design, synthesis and characterization of a fluorinated elastomer (FBE15) that utilizes enhanced interaction between polymer chains afforded by strong dipole‐dipole interactions from −CF3, which showed a significant increase in binding energy to −7.71 Kcal/mol from −5.51 Kcal/mol, resulting in increased interaction between the boronic ester linkages and improving self‐healing capabilities of boronic ester materials, drastically reducing the time required for stress relaxation by 900 %. The bulk elastomer is capable of ultrafast self‐healing in a one‐click fashion that can happen in mere seconds, which can then be stretched to 150 % of its original length. By utilising the dynamic cross‐linking, FBE15 is also capable of both mechanical reprocessing into the same materials and chemical recycling into its starting materials, respectively, further allowing reconstruction of the elastomers that have comparable properties to the original ones at the end of its service lifespan. [ABSTRACT FROM AUTHOR]

Frequent removal and reapplication of wound dressings can cause mechanical disruption to the healing process and significant physical discomfort for patients. In response to this challenge, a dynamic covalent hydrogel has been developed to advance wound care strategies. This system comprises aldehyde functionalized chondroitin sulfate (CS-CHO) and thiolated hyaluronic acid (HA-SH), with the distinct ability to form in situ via thiol–aldehyde addition and dissolve on-demand via the thiol–hemithioacetal exchange reaction. Although rarely reported, the dynamic covalent reaction of thiol–aldehyde addition holds great promise for the preparation of dynamic hydrogels due to its rapid reaction kinetics and easy reversible dissociation. The thiol–aldehyde addition chemistry provides the hydrogel system with highly desirable characteristics of rapid gelation (within seconds), self-healing, and on-demand dissolution (within 30 min). The mechanical and dissolution properties of the hydrogel can be easily tuned by utilizing CS-CHO materials of different aldehyde functional group contents. The chemical structure, rheology, self-healing, swelling profile, degradation rate, and cell biocompatibility of the hydrogels are characterized. The hydrogel possesses excellent biocompatibility and proves to be significant in promoting cell proliferation in vitro when compared to a commercial hydrogel (HyStem® Cell Culture Scaffold Kit). This study introduces the simple fabrication of a new dynamic hydrogel system that can serve as an ideal platform for biomedical applications, particularly in wound care treatments as an on-demand dissolvable wound dressing. [ABSTRACT FROM AUTHOR]

3D printing is a low cost, customizable, and fast‐growing technology with the potential to revolutionize plastic manufacturing. Vat photopolymerization 3D printing technologies stand out for their high resolution, however, the resulting printed materials are made from petroleum feedstocks and are covalently crosslinked which renders them unrecyclable. Here, resin formulations with 70 wt% bio‐based content and dynamic functionality are synthesized and printed using lignin, vanillin, and soybean oil components. These printed polymers can undergo dynamic transesterification due to the methacrylated lignin (LMA) to allow for self‐healing capabilities; therefore, potentially increasing the materials lifetimes compared to traditional thermoset materials, offsetting the use of traditional petroleum‐based resins, and lowering their environmental impact. The LMA also provides the thermosets with better mechanical performance and thermal stability in comparison to the controls. Additionally, compatibility with 3D printing technologies improves the competitiveness of biobased plastics with conventional materials. [ABSTRACT FROM AUTHOR]

Molecular scaffolds that enable the combinatorial synthesis of new supramolecular building blocks are promising targets for the construction of functional molecular systems. Here, we report a supramolecular scaffold based on boroxine that enables the formation of chiral and ordered 1D supramolecular polymers, which can be easily functionalized for circularly polarized luminescence. The boroxine monomers are quantitatively synthesized in situ, both in bulk and in solution, from boronic acid precursors and cooperatively polymerize into 1D helical aggregates stabilized by threefold hydrogen‐bonding and π–π stacking. We then demonstrate amplification of asymmetry in the co‐assembly of chiral/achiral monomers and the co‐condensation of chiral/achiral precursors in classical and in situ sergeant‐and‐soldiers experiments, respectively, showing fast boronic acid exchange reactions occurring in the system. Remarkably, co‐condensation of pyrene boronic acid with a hydrogen‐bonding chiral boronic acid results in chiral pyrene aggregation with circularly polarized excimer emission and g‐values in the order of 10−3. Yet, the electron deficiency of boron in boroxine makes them chemically addressable by nucleophiles, but also sensitive to hydrolysis. With this sensitivity in mind, we provide first insights into the prospects offered by boroxine‐based supramolecular polymers to make chemically addressable, functional, and adaptive systems. [ABSTRACT FROM AUTHOR]

Aromatic‐carbonyl (Ar···C═O) interactions, attractive interactions between the arene plane and the carbon atom of carbonyl, are in the infancy as one type of new supramolecular bonding forces. Here the study and functionalization of aromatic‐carbonyl interactions in solution is reported. A combination of aromatic‐carbonyl interactions and dynamic covalent chemistry provided a versatile avenue. The stabilizing role and mechanism of arene‐aldehyde/imine interactions are elucidated through crystal structures, NMR studies, and computational evidence. The movement of imine exchange equilibria further allowed the quantification of the interplay between arene‐aldehyde/imine interactions and dynamic imine chemistry, with solvent effects offering another handle and matching the electrostatic feature of the interactions. Moreover, arene‐aldehyde/imine interactions enabled the reversal of kinetic and thermodynamic selectivity and sorting of dynamic covalent libraries. To show the functional utility diverse modulation of fluorescence signals is realized with arene‐aldehyde/imine interactions. The results should find applications in many aspects, including molecular recognition, assemblies, catalysis, and intelligent materials. [ABSTRACT FROM AUTHOR]

Abstract Dynamic‐covalent electrophiles called cascade exchangers (CAXs) can reversibly engage cell‐surface thiols. Conjugates between CAXs and molecular or even protein‐sized cargos can deliver these cargos into cells by thiol‐mediated uptake (TMU); free CAXs can also hinder TMU presumably by competing for thiol exchange sites. So far, three orthogonal networks of cellular thiol exchange partners have been identified to participate in TMU, centering on the transferrin receptor, integrins, and protein disulfide isomerases. This study introduces cyclic selenenylsulfides as a new CAX type, with polarised reactivity that brings important differences from the known disulfide and diselenide CAXs. Additionally, this study introduces methods to modulate CAX activity by employing remote functional groups to tune ring re‐closure rates, e. g. via thiolate de/stabilization by hydrogen bonding and ion pairing. Differently to all CAXs known, Se‐centred CAXs participate in two different TMU networks (integrins preferred, PDIA3 tolerated). When free, the remotely tuned Se‐centred CAXs were strong inhibitors of most TMU systems, but again brought a novel feature: they increased the uptake of tetrel‐centred Michael acceptor CAXs, making them the first free CAX we know of that can accelerate TMU. We conclude that Se‐ and tetrel‐centred CAXs share a cellular thiol exchange partner that hinders TMU, which may be a target for improving the delivery of Michael acceptor drugs. The unique thiol exchange partner patterns generated by Se‐centered CAXs with remotely tuned ring closure motifs support that they will prove a valuable tool to help decode TMU and achieve chemical control over cellular entry on the molecular level.

Yun Liu,1,2 Timo Hamm,3 Thomas Ralf Eichinger,3 Walter Kamm,3 Heike Andrea Wieland,3 Brigitta Loretz,1 Anna KH Hirsch,2,4 Sangeun Lee,1,2 Claus-Michael Lehr1,2 1Department of Drug Delivery Across Biological Barriers, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarbrücken, Germany; 2Department of Pharmacy, Saarland University, Saarbrücken, Germany; 3Department of Research and Development, Sanofi-Aventis Deutschland GmbH, Frankfurt Am Main, Germany; 4Department of Drug Design and Optimisation, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarbrücken, GermanyCorrespondence: Claus-Michael Lehr, Department of Drug Delivery Across Biological Barriers, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarbrücken, Germany, Tel +49 681 98806-1000, Fax +49 681 98806 1009, Email Claus-Michael.Lehr@helmholtz-hips.de Sangeun Lee, Department of Pharmacy, Saarland University, Saarbrücken, Germany, Tel +49 681 302 4764, Fax +49 681 302 2028, Email Sangeun.Lee@uni-saarland.deBackground: Therapeutic proteins and peptides offer great advantages compared to traditional synthetic molecular drugs. However, stable protein loading and precise control of protein release pose significant challenges due to the extensive range of physicochemical properties inherent to proteins. The development of a comprehensive protein delivery strategy becomes imperative accounting for the diverse nature of therapeutic proteins.Methods: Biodynamers are amphiphilic proteoid dynamic polymers consisting of amino acid derivatives connected through pH-responsive dynamic covalent chemistry. Taking advantage of the amphiphilic nature of the biodynamers, PNCs and DEs were possible to be prepared and investigated to compare the delivery efficiency in drug loading, stability, and cell uptake.Results: As a result, the optimized PNCs showed 3-fold encapsulation (< 90%) and 5-fold loading capacity (30%) compared to DE-NPs. PNCs enhanced the delivery efficiency into the cells but aggregated easily on the cell membrane due to the limited stability. Although DE-NPs were limited in loading capacity compared to PNCs, they exhibit superior adaptability in stability and capacity for delivering a wider range of proteins compared to PNCs.Conclusion: Our study highlights the potential of formulating both PNCs and DE-NPs using the same biodynamers, providing a comparative view on protein delivery efficacy using formulation methods. Keywords: amphiphilic polymer, nanocomplex, double emulsion, pH-responsive, protein delivery, dynamic covalent chemistry

Directional bonding strategies guide the design of complex molecular architectures, yet challenges arise due to emergent behavior. Rigid structures face geometric constraints and sensitivity to mismatches, hindering the efficient assembly of molecular organic cages (MOCs). Harnessing intramolecular non‐covalent interactions offers a promising solution, broadening geometrical possibilities and enhancing adaptability to boost assembly yields. However, identifying these interactions remains challenging, with their full potential sometimes latent until final assembly. This study explores these challenges by synthesizing boronic acid tripods with varied oxygen positions at the tripodal feet and investigating their role in assembling tetrahedral boronate MOCs. Our results reveal substantial differences in the assembly efficiency among tripods. While the building blocks with oxygen in the benzylic position relative to the central aromatic ring form the MOCs in high yields, those with the oxygen atom directly bound to the central aromatic ring, only yield traces. Through X‐ray crystallography and DFT analyses, we elucidate how intramolecular interactions profoundly influence the geometry of the building blocks and cages in a relay‐like fashion, highlighting the importance of considering intramolecular interactions in the rational design of (supra)molecular architectures. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) have garnered significant attention for nearly two decades due to their exceptional structural designs, tunable properties, and wide‐ranging applications. Recently, a novel subclass of COFs known as partially condensed, sub‐stoichiometric COFs (ss‐COFs) has emerged. This presents a promising new avenue for constructing distinct COF structures in contrast to fully condensed, stoichiometric COFs (fc‐COFs). ss‐COFs are deliberately designed with periodic unreacted functional groups, thereby giving rise to intriguing electronic, optical, and catalytic properties. The deviation from conventional stoichiometric approach opens up new prospects to tailor material properties for unexplored applications. Here, this review focuses on the latest advancements and breakthroughs in ss‐COFs, including topological design, structure characterization, synthetic method, and practical applications. From their basic designing principles to cutting‐edge properties, it will be explored how ss‐COFs are paving the way for COFs research and pushing the boundaries toward new scientific and technological possibilities. [ABSTRACT FROM AUTHOR]

Dynamic Covalent Chemistry, consisting in the use of dynamic covalent bonds (DCBs) to create complex objects by working at the thermodynamic equilibrium, has undeniable advantages for the preparation of conjugated systems with tailored optoelectronic properties for organic electronics. Chemists can combine simple building blocks with simple functional groups of appropriate geometry, structure and stoichiometry to build multidimensional conjugated architectures. Dynamic covalent reactions are often precious metal‐free, generate little to no side products and are very efficient. DCBs however afford sensitive materials, and consequently a balance needs to be found between the ease of synthesis, the stability and the performances. The dynamicity of the target materials hence can considerably reduce their applicability in organic electronics where strongly stable materials are needed, but opens the door to stimuli‐responsive behaviour and recyclability. A way to overcome dynamicity issues is to lock DCBs, but often at the cost of decreased conjugation. In this review, we will highlight how DCBs are employed to prepare functional optoelectronically active materials, such as discrete molecules, polymers or covalent organic frameworks, applied in fields ranging from organic light‐emitting diodes and solar cells to organic batteries and transistors. We will also discuss their limitations, benefits and the current challenges to overcome. [ABSTRACT FROM AUTHOR]

Exploring innovative strategies for molecular structuring of dynamic materials that combine self‐correcting intrinsic reversibility with the robustness of covalent bonds, has been a long‐standing objective from applications perspective in fields ranging from molecular engineering to nanotechnology and interfacial science. To establish dynamic covalent chemistry approaches combined with interfacial polymerization, herein, a distinct synthetic approach is reported to develop disulfide‐bridged 2D polymeric C3N3S3 triazine thin‐films by interfacial thiol‐disulfide dynamic exchange process crosslinking tritopic planar 1,3,5‐triazine‐2,4,6‐trithiol molecular tectons via intermolecular disulfide formation in the presence of I2 vapors at the air/water interface under redox condition. The resulting centimeter‐scale polymeric thin‐films are covalently cross‐linked, dynamic in nature, featuring tunable thickness (6–200 nm) and significant morphological variations are realized under the influence of varying reaction time, concentration and types of reducing agents. Notably, C3N3S3 polymer thin films exhibit a transflectance of around 99.5% in the range from 430 to 1800 nm, show high refractive indices (1.730–1.488) and optical anisotropy with uniaxial negative birefringence. The C3N3S3 free‐standing polymer thin‐films can be easily transferred to different substrates or possibly into application‐relevant forms for device fabrications, making this useful from materials application perspective. [ABSTRACT FROM AUTHOR]

Naturally occurring polymeric structures often consist of 1D polymer chains intricately folded and entwined through non‐covalent bonds, adopting precise topologies crucial for their functionality. The exploration of crystalline 1D polymers through dynamic covalent chemistry (DCvC) and supramolecular interactions represents a novel approach for developing crystalline polymers. This study shows that sub‐angstrom differences in the counter‐ion size can lead to various helical covalent polymer (HCP) topologies, including a novel metal‐coordination HCP (m‐HCP) motif. Single‐crystal X‐ray diffraction (SCXRD) analysis of HCP−Na revealed that double helical pairs are formed by sodium ions coordinating to spiroborate linkages to form rectangular pores. The double helices are interpenetrated by the unreacted diols coordinating sodium ions. The reticulation of the m‐HCP structure was demonstrated by the successful synthesis of HCP−K. Finally, ion‐exchange studies were conducted to show the interconversion between HCP structures. This research illustrates how seemingly simple modifications, such as changes in counter‐ion size, can significantly influence the polymer topology and determine which supramolecular interactions dominate the crystal lattice. [ABSTRACT FROM AUTHOR]

Polymer compatibilization plays a critical role in achieving polymer blends with favorable mechanical properties and enabling efficient recycling of mixed plastic wastes. Nonetheless, traditional compatibilization methods often require tailored designs based on the specific chemical compositions of the blends. In this study, we propose a new approach for compatibilizing polymer blends using a dynamically crosslinked polymer network, known as vitrimers. By adding a relatively small amount (1–5 w/w%) of a vitrimer made of siloxane‐crosslinked high‐density polyethylene (HDPE), we successfully compatibilized unmodified HDPE and isotactic polypropylene (iPP). The vitrimer‐compatibilized blend exhibited enhanced elongation at break (120 %) and smaller iPP domain sizes (0.4 μm) compared to the control blend (22 % elongation at break, 0.9 μm iPP droplet size). Moreover, the vitrimer‐compatibilized blend showed significantly improved microphase stability during annealing at 180 °C. This straightforward method shows promise for applications across various polymer blend systems. [ABSTRACT FROM AUTHOR]

We present the multiple post‐modification of organic macrocycles and cages, introducing functional groups into two‐ and three‐dimensional supramolecular scaffolds bearing fluorine substituents, which opens up new possibilities in multi‐step supramolecular chemistry employing the vast chemical space of readily available isocyanates. The mechanism and scope of the reaction that proceeds after isocyanate addition to the benzylamine motif via an azadefluorination cyclisation (ADFC) were investigated using DFT calculations, and a series of aromatic isocyanates with different electronic properties were tested. The compounds show excellent chemical stability and were fully characterised. They can be used for subsequent cross‐coupling reactions, and ADFC can be used directly to generate cross‐linked membranes from macrocycles or cages when using ditopic isocyanates. Single‐crystal X‐ray (SC‐XRD) analysis shows the proof of the formation of the desired supramolecular entity together with the connectivity predicted by calculations and from 19F NMR shifts, allowing the late‐stage functionalisation of self‐assembled macrocycles and cages by ADFC. [ABSTRACT FROM AUTHOR]

An outstanding challenge in modern society remains how to make crosslinked polymers (thermosets) more recyclable. A breakthrough solution to this challenge has been the introduction of dynamic covalent bonds in polymer networks, yielding covalent adaptable networks (CANs). Ongoing research is focused on finding new suitable dynamic covalent chemistries and on how to tune the material properties of CANs derived from these new chemistries. Here, we first compare two different dynamic boronic acid based covalent adaptable networks, namely, a conventional boronate‐diol and a novel boronate‐TetraAzaADamantane (TAAD) system. We show that incorporating boronate‐TAAD bonds in networks results in stiffer materials, as seen in a slower relaxation and higher shear and storage moduli. This offers access to more mechanically robust boronate‐based materials, compared to conventional boronate‐based gels. Next, we investigate the effect of molecular tuning via the electron density of meta‐positioned ring substituents on the macroscopic material properties for the boronate‐TAAD network. By comparing relaxation experiments on materials with different substituents, we show that the macroscopic network relaxation can be tuned through the Hammett parameter of the meta‐substituent and the activation energy of the boronate‐TAAD exchange. This enables subtle control over the (dynamic) material properties of these novel, robust boronate‐based networks. [ABSTRACT FROM AUTHOR]

Petroleum‐derived monomers are the most common building blocks for ester‐based thermosets. Bio‐derived thermoset elastomers are becoming viable alternatives to conventional thermosets. Herein, we developed a biobased vitrimer‐type thermoset elastomers using abundant and sustainable raspberry ketone as feedstock. We utilize raspberry ketone to create building blocks for dynamic oxime chemistry and crosslinked these through free radical polymerization with poly(ethylene glycol) methyl ether methacrylate as a comonomer. In contrast to other dynamic networks based on ester bonds, which need catalysts, this is undesirable since catalyst deactivation or leaching lowers its effect over time and may impair reuse. This network incorporates catalyst‐free bond exchange reactions in catalyst‐dependent polyester networks by substituting oxime‐esters for typical ester linkages. The elastomer exhibits stress relaxation, a low glass transition temperature (Tg) (−55 to −40.2°C) and tensile strength up to 5.2 ± 3.0 kPa. Furthermore, the dynamic oxime transesterification exchange mechanism allows elastomers to be reprocessed using a hot press at 160°C and 8 × 103 kPa pressure. After reprocessing, the tensile strength of elastomers can be recovered up to 78.1 ± 10.9%. This work integrates the principles of catalyst‐free dynamic exchange process and mechanical recycling coupled with biobased components to provide a rational solution towards conventional elastomers. In the future, these elastomers can be exploited for the development of hydrogels, recyclable elastomers, and commodity plastics. [ABSTRACT FROM AUTHOR]

3D printing, a rapidly growing material processing technique has found its broad applications in construction, automobiles, robotics, domestic usage and in biomedical sectors due to its ability to fabricate the desirable objects from scratch. However, due to the non-recyclable and non-reprocessable nature of most printed structures, the discarded 3D printed objects generate wastes after damage or use. Covalent Adaptable Networks (CANs) are polymeric networks those can change their network topology by exchanging their functionalities under external stimuli, thus, rendering the printed objects recyclable, therefore helpful in terms of reducing waste. The fabricated objects may also be endowed with properties such as self-healing, shape-memory, enhanced mechanical strength, degradability, and reprintability. The present article covers different methods utilized for 3D printing of the polymers having CANs, including a detailed insight to present trends and technologies in the field. In addition, their applications, particularly in soft robotics and biomedical fields have been discussed. Future perspectives regarding the challenges, new potential applications as well as importance of continuous advancements in the field of 3D printing of CANs have also been discussed. [ABSTRACT FROM AUTHOR]

In situ preparation of bifunctional thiazolo[5,4‐d]thiazole (TTz)‐based fluorophore cross‐linked nanofibers is successfully performed. These multifunctional nanofibers are used as both crystal growth template and antibacterial substrate that makes bacterial detection possible simultaneously. These highly fluorescent nanofibers act as optical sensors toward many analytes. The acid, base, and metal cation‐sensitive nature of the 2,5‐bis(4‐hydroxyphenyl)thiazolo[5,4‐d]thiazole (HPhTT) dye makes the prepared PVA nanofibers sensitive against these chemicals. Metal nanoparticles (MNPs) or metal oxide crystal formation occurs on the surface of nanofibers without any reducing agent. The strong interaction between metal cations and fluorophores results in crystal formation on the surface, which is named for the first time as "complexation‐triggered crystalization." These dye cross‐linked and metal‐interacted nanofibers exhibit antibacterial effect against E. coli (ATCC 25922), S. aureus (ATCC 25923), P. aeruginosa (ATCC 27853), and E. faecalis (ATCC 25922) strains. Also, the emission wavelength change of nanofibers in bacterial contamination makes it possible to use smart nanofiber films for optical bacteria detection. These novel materials pave the way for new applications such as smart wound bands, optical sensors, and one‐step preparation of surface‐enhanced Raman spectroscopy substrate. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) are a fast‐developing family of porous organic materials that have received substantial research interest during the last two decades. Dynamic covalent chemistry (DCC) is the cornerstone of COF fabrication. DCC is a process that entails reversible bond breaking‐reforming under equilibrium to attain the thermodynamically most stable structure. Due to the reversible nature of the covalent linkages, the building blocks of pre‐synthesized COF or pre‐assembled chemical entities, like network polymers and supramolecular hosts, can be replaced postsynthetically under appropriate reaction conditions. The technique is known as postsynthetic linker exchange (PLE). PLE provides an easy way to introduce functional building blocks into the COF backbone and control its chemical and physical properties. In this article, we have highlighted the recent advancements (from 2017 to 2023) in the postsynthetic linker exchange strategy for constructing highly crystalline and porous COFs that are often unattainable via de novo fabrication. The mechanistic insights of the linker exchange process for transforming various parent entities, such as COFs, amorphous covalent organic networks, linear polymers, and molecular cages to daughter COFs, have been deliberated with fascinating examples. We have also outlined some future avenues for applying the PLE process for the large‐scale fabrication of highly crystalline COFs for real‐time applications. [ABSTRACT FROM AUTHOR]

In this study, we introduce phosphorus, a pnictogen, as an exchange center for dynamic covalent chemistry. Cascade exchange of neutral phosphorotri‐ and ‐tetrathioates with thiolates is demonstrated in organic solvents, aqueous micellar systems, and in living cells. Exchange rates increase with the pH value, electrophilicity of the exchange center, and nucleophilicity of the exchangers. Molecular walking of the dynamic phosphorus center along Hammett gradients is simulated by the sequential addition of thiolate exchangers. Compared to phosphorotrithioates, tetrathioates are better electrophiles with higher exchange rates. Dynamic phosphorotri‐ and ‐tetrathioates are non‐toxic to HeLa Kyoto cells and participate in the dynamic networks that account for thiol‐mediated uptake into living cells. [ABSTRACT FROM AUTHOR]