Search

Porphyrins and their derivatives have attracted great attention due to their unique properties and diverse functionalities which contribute to their wide applications such as catalysis, solar cells, biomedicine and environmental science. It is interesting to note that porphyrin-containing polymers have recently aroused great interest due to the simultaneous presence of both porphyrinic and polymeric characteristics, especially for porphyrin-containing polymers linked by covalent bonds giving well-defined macromolecular architectures, unique self-assembly morphologies and promising applications. Herein, we summarize the different synthetic strategies and self-assembly protocols adopted in recent years to explore various applications of porphyrin-based functional polymers followed by a brief discussion on the challenges and outlooks for future research. With the discovery of advanced polymerization techniques such as living/controlled radical polymerization and click chemistry, the synthesis of porphyrin-containing functional polymers with well-defined architectures has been greatly developed. Porphyrin molecules tend to form the aggregates based on the self-assembly driving force of π-π stacking. Much attention has been paid to the self-assembly behavior of porphyrin-containing functional polymers, and various nanostructures have been constructed including nano-sized or micron-sized spheres, vesicles, belts, wires, rings, tubes, and rods. Porphyrin-containing functional polymers, with special photochemical and photophysical properties, present significant applications in photovoltaics, catalysis, biological and biomedicine fields. Particularly, the porphyrin-based photosensitizers for photodynamic therapy, porphyrin-conjugated polymers for solar cell devices, porphyrin-based polymeric nanocomposites in catalysis and chemical adsorption and separation have been widely studied. We hope this review on porphyrin-based functional polymers will be beneficial to researchers and newcomers in related fields. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Construction of redox-responsive porphyrin-based amphiphilic copolymer nanoparticles. • High content disulfide units and porphyrin units contribute the alternating structure. • Appropriate and stable size enhances the cellular uptake efficiency of nanoparticles. • Redox-triggered rapid porphyrin release and enhancing 1O 2 generation in cancer cells. Abstract Stimulus-sensitive nanoparticles (NPs) have been established to widely adapt to remarkable abnormalities under the tumor microenvironment, which can observably enhance the therapeutic efficiency, improve the specific targeting ability and reduce the side effects. Photodynamic therapy (PDT) as a promising non-invasive and selective treatment for cancers through photodynamic reaction can profit from stimulus-sensitive NPs. Herein, a harmonious amphiphilic polymer (PEG- b -PTPPDS- b -PEG) with an extremely sensitive redox response is constructed via click chemistry between N 3 -TPPC6-N 3 , PEG-N 3 and alkynyl-containing disulfide ester for PDT. This polymer can be self-assembled into micelles with excellent stability, ultra-fast sensitivity of redox-triggered porphyrin release, and significant photodynamic anticancer performance. The redox-triggered dissociation of micelles and the release of porphyrin are much faster than common porphyrin-containing polymer. The bio-distribution and phototoxicity of micelles against A549 cells are measured and evaluated in vitro by flow cytometry, confocal scanning laser microscopy (CLSM) and MTT assay, respectively. The results reveal that PEG- b -PTPPDS- b -PEG micelles can effectively enhance the cellular uptake and cellular internalization of porphyrin and have an extremely low dark toxicity with efficient PDT towards A549 cells. This intracellular responsive nanoparticle provides a potential strategy for anticancer therapeutic application. [ABSTRACT FROM AUTHOR]

Materials with Janus structures are attractive for wide applications in materials science. Although extensive efforts in the synthesis of Janus particles have been reported, the synthesis of sub-10 nm Janus nanoparticles is still challenging. Herein, the synthesis of Janus gold nanoparticles (AuNPs) based on interface-directed self-assembly is reported. Polystyrene (PS) colloidal particles with AuNPs on the surface were prepared by interface-directed self-assembly, and the colloidal particles were used as templates for the synthesis of Janus AuNPs. To prepare colloidal particles, thiol-terminated polystyrene (PS-SH) was dissolved in toluene and citrate-stabilized AuNPs were dispersed in aqueous solution. Upon mixing the two solutions, PS-SH chains were grafted to the surface of AuNPs and amphiphilic AuNPs were formed at the liquid-liquid interface. PS colloidal particles decorated with AuNPs on the surfaces were prepared by adding the emulsion to excess methanol. On the surface, AuNPs were partially embedded in the colloidal particles. The outer regions of the AuNPs were exposed to the solution and were functionalized through the grafting of atom-transfer radical polymerization (ATRP) initiator. Poly[2-(dimethamino) ethyl methacrylate] (PDMAEMA) on AuNPs were prepared by surface-initiated ATRP. After centrifugation and dissolving the colloidal particles in tetrahydrofuran (THF), Janus AuNPs with PS and PDMAEMA on two hemispheres were obtained. In acidic pH, Janus AuNPs are amphiphilic and are able to emulsify oil droplets in water; in basic pH, the Janus AuNPs are hydrophobic. In mixtures of THF/methanol at a volume ratio of 1:5, the Janus AuNPs self-assemble into bilayer structures with collapsed PS in the interiors and solvated PDMAEMA at the exteriors of the structures. [ABSTRACT FROM AUTHOR]

Selective preparation of two‐dimensional polymers (2DPs) and supramolecular polymers (2DSPs) with defined thickness is crucially important for controlling and maximizing their functions, yet it has remained as a synthetic challenge. In the past decade, several approaches have been developed to allow selective preparation of discrete monolayer 2DPs and 2DSPs. Recently, crystal exfoliation and self‐assembly strategies have been employed to successfully prepare bilayer 2DP and 2DSP, which represent the first step towards the controlled "growth" of 2D polymers from the thinnest monolayers to thicker few‐layers along the third dimension. This Concept review discusses the concept of accurate synthesis of 2D polymers with defined layers. Advances in this research area will pave the way to rational synthetic strategies for 2D polymers with controlled thickness. [ABSTRACT FROM AUTHOR]

Polypeptides, as natural polyelectrolytes, are assembled into tailored proteins to integrate chromophores and catalytic sites for photosynthesis. Mimicking nature to create the water‐soluble nanoassemblies from synthetic polyelectrolytes and photocatalytic molecular species for artificial photosynthesis is still rare. Here, we report the enhancement of the full‐spectrum solar‐light‐driven H2 production within a supramolecular system built by the co‐assembly of anionic metalloporphyrins with cationic polyelectrolytes in water. This supramolecular photocatalytic system achieves a H2 production rate of 793 and 685 μmol h−1 g−1 over 24 h with a combination of Mg or Zn porphyrin as photosensitizers and Cu porphyrin as a catalyst, which is more than 23 times higher than that of free molecular controls. With a photosensitizer to catalyst ratio of 10000 : 1, the highest H2 production rate of >51,700 μmol h−1 g−1 with a turnover number (TON) of >1,290 per molecular catalyst was achieved over 24 h irradiation. The hierarchical self‐assembly not only enhances photostability through forming ordered stackings of the metalloporphyrins but also facilitates both energy and electron transfer from antenna molecules to catalysts, and therefore promotes the photocatalysis. This study provides structural and mechanistic insights into the self‐assembly enhanced photostability and catalytic performance of supramolecular photocatalytic systems. [ABSTRACT FROM AUTHOR]

Polypeptides, as natural polyelectrolytes, are assembled into tailored proteins to integrate chromophores and catalytic sites for photosynthesis. Mimicking nature to create the water‐soluble nanoassemblies from synthetic polyelectrolytes and photocatalytic molecular species for artificial photosynthesis is still rare. Here, we report the enhancement of the full‐spectrum solar‐light‐driven H2 production within a supramolecular system built by the co‐assembly of anionic metalloporphyrins with cationic polyelectrolytes in water. This supramolecular photocatalytic system achieves a H2 production rate of 793 and 685 μmol h−1 g−1 over 24 h with a combination of Mg or Zn porphyrin as photosensitizers and Cu porphyrin as a catalyst, which is more than 23 times higher than that of free molecular controls. With a photosensitizer to catalyst ratio of 10000 : 1, the highest H2 production rate of >51,700 μmol h−1 g−1 with a turnover number (TON) of >1,290 per molecular catalyst was achieved over 24 h irradiation. The hierarchical self‐assembly not only enhances photostability through forming ordered stackings of the metalloporphyrins but also facilitates both energy and electron transfer from antenna molecules to catalysts, and therefore promotes the photocatalysis. This study provides structural and mechanistic insights into the self‐assembly enhanced photostability and catalytic performance of supramolecular photocatalytic systems. [ABSTRACT FROM AUTHOR]

Review: 95 refs. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) represent a promising class of porous materials. However, MOFs show poor processability that impedes their full potential in applications. This work develops a composite strategy to skillfully load MOFs on a polymer plate to afford processability for these powder materials. A predesigned mesoporous MOF with active −NH2 groups around the pore walls was prepared and its copolymerization with the −NCO groups of macromonomers (polyurethane acrylate) could be facilely induced by an initiator under mild conditions. Notably, the target MOF-polymer composite is transparent, elastic, and shows enhanced Fe3+ detection compared with that of the individual MOF functional component. This result can be ascribed to the synergistic effect of the composite with newly formed chemical bonds between the MOF particle and polymer matrix. [ABSTRACT FROM AUTHOR]

Phototherapies including photodynamic therapy (PDT) and photothermal therapy (PTT) are the most promising and non-invasive cancer treatments. However, the efficacy of mono-therapy of PDT or PTT is often limited by the phototherapeutic defects such as low light penetration depth of photosensitizers and insufficiency of photothermal agents. Peroxynitrite (ONOO−) has been proved to be an efficient oxidizing and nitrating agent that involves in various physiological and pathological processes. Therefore, ONOO− produced in tumor site could be an effective treatment in cancer therapy. Herein, a novel cyanine dye-based (Cy7) polymer nanoplatform is developed for enhanced phototherapy by in situ producing ONOO−. The Cy7 units in the nanoparticles can not only be served as the photosensitizer to produce reactive oxygen species (ROS) including singlet oxygen and superoxide anion for PDT, but also be used as a heat source for PTT and the release of NO gas from N-nitrosated napthalimide (NORM) at the same time. Since NO can react quickly with superoxide anion to generate ONOO−, the enhanced phototherapy could be achieved by in situ ONOO− produced by PCy7-NO upon exposure to the near infrared (NIR) light. Therefore, the NIR-triggered Cy7-based nanoplatform for ONOO−-enhanced phototherapy may provide a new perspective in cancer therapy. [ABSTRACT FROM AUTHOR]

To further explore the coordination possibilities of the flexible tripodal ligand, 4,4′,4′′-(benzene-1,3,5-triyl-tris(oxy))tribenzoic acid (H3BTTB), two solvent-controlled three-dimensional (3D) manganese(II) coordination polymers, [Mn3(BTTB)2(H2O)4](H2O)2 ( 1) and [Mn3(BTTB)2(DMF)2](DMF)2 ( 2), were synthesized and characterized. Single crystal X-ray diffraction analysis indicates that in the MnII complexes the BTTB ligands exhibit two coordination modes, which have not been reported previously. Complexes 1 and 2 involve different one-dimensional (1D) rod-shaped metal-carboxylate secondary building units (SBUs). The 1D SBUs are further extended to afford two different three-dimensional (3D) frameworks with similar flu topology via linkage of the BTTB ligands. The results demonstrate that the reaction solvent as well as conformation and coordination mode of BTTB ligands play key roles on the formation of the final framework structures. Additionally, their luminescent properties were investigated. [ABSTRACT FROM AUTHOR]