Rui Qu

Isotactic poly(propylene oxide) (iPPO) is a robust polyether with photodegradability. However, its stereoselective synthesis from racemic propylene oxide (rac-PO) remains dominated by preconfigured axially chiral cobalt/chromium bimetallic catalysts. Here, we report an ion pair-assisted dynamic helical organization strategy employing a bifunctional multi-aluminum porphyrin (BMAlP) catalyst for stereocontrolled synthesis of iPPO. This approach affords highly isotactic PPO with [mm] up to 97.6%, ultrahigh viscometric molecular weight (Mv up to 6700 kDa), and a tensile strength of 92 MPa comparable to nylon-66. Mechanistic studies reveal that π–π interactions among polyacrylate-supported porphyrin generate dynamic P/M helical organizations, while ion pairs stabilize hierarchical organization and promote cooperative aluminum-site arrangement, creating locally persistent enantiomorphic catalytic environments for enantiomorphic-site-controlled PO insertion. This work establishes dynamic supramolecular chirality as an alternative strategy for stereoselective polymerization beyond static molecular chirality.

Construction of CO₂‐based amphiphilic block copolymers (ABCs) is an efficient method for providing CO₂‐based polycarbonates with self‐assembly properties in aqueous media. It is challenging to construct CO₂‐based ABCs by one‐step strategies from mixed monomers because hydrophilic blocks, usually composed of polar monomers, have negative effects on the synthesis of polycarbonates. In this work, we report a one‐step method to construct CO₂‐based ABCs obtained by simultaneous ring‐opening copolymerization (ROCOP) of CO₂/epoxides and reversible addition‐fragmentation chain transfer (RAFT) polymerization of N‐isopropyl acrylamide (NIPAM). A trithiocarbonate/carboxy compound was used as the bifunctional chain transfer agent, and an aluminum porphyrin complex was used as the catalyst for ROCOP, which proved to be efficient in CO₂ copolymerization even in the presence of NIPAM with strong polarity. This strategy allows flexible control over the molecular weight (5–16 kg/mol) and the hydrophilic‐hydrophobic balance (HLB 9–18) of the ABCs, and ensures narrow polydispersity Đ (1.1–1.3) of the polymers. The ABCs can further self‐assemble into micelles in water with controllable diameters and reversible phase transformation behavior with temperature changes from 25 to 40 °C. This simple route to CO₂‐based ABCs with multiple functions has large potential in biomedical applications.

Inspired by the cooperative multi-metallic activation in metalloenzyme catalysis, artificial enzymes as multi-metallic catalysts have been developed for improved kinetics and higher selectivity. Previous models about multi-metallic catalysts, such as cross-linked polymer-supported catalysts, failed to precisely control the number and location of their active sites, leading to low activity and selectivity. In recent years, metallopolymers with metals in the sidechain, also named as sidechain metallopolymers (SMPs), have attracted much attention because of their combination of the catalytic, magnetic, and electronic properties of metals with desirable mechanical and processing properties of polymeric backbones. Living and controlled polymerization techniques provide access to SMPs with precisely controlled structures, for example, controlled degree of polymerization (DP) and molecular weight dispersity (Đ), which may have excellent performance as multi-metallic catalysts in a variety of catalytic reactions. This review will cover the recent advances about SMPs, especially on their synthesis and application in catalysis. These tailor-made SMPs with metallic catalytic centers can precisely control the number and location of their active sites, exhibiting high catalytic efficiency.

Inspired by the structures of antenna-reaction centers in photosynthesis, a complex micelle was prepared from zinc tetrakis(4-sulfonatophenyl) porphyrin (ZnTPPS), modified fullerene (mC₆₀) and poly(ethylene glycol)-block-poly(L-lysine) (PEG-b-PLys) by electrostatic interactions. The core–shell structure made the donor–acceptor system work in an aqueous environment. In the micellar core, ZnTPPS and mC₆₀ molecules were surrounded by each other which ensured effective energy migration from the donor to the acceptor. The emission of the porphyrin was quenched efficiently which was confirmed by a series of fluorescence spectra. In comparison with the ZnTPPS micelle, the interaction of the mC₆₀ with the porphyrin inhibited the generation of singlet oxygen, which was measured by electron paramagnetic resonance (EPR) and iodide method. In addition, enhanced generation of the superoxide radical was detected by reduction of nitro blue tetrazolium (NBT) in the presence of an electron donor. What is more, the complex micelle exhibited high electron transfer performance in the photocatalytic reduction of methyl viologen. The complex micellar structure endowed the donor–acceptor system with improved stability in an acidic environment. This strategy would be helpful for designing a new electron transfer platform and artificial photosynthetic system.

Hemin-micelles immobilized in hydrogels were designed, which function as efficient artificial enzymes with high catalytic activity and substrate selectivity.

This review covers recent research on design strategies for the cooperative self-assembly of porphyrins with polymers and its implementation as bioactive assembly.

Herein, a complex micelle as an oxygen nano-carrier is constructed through the hierarchical assembly of the diblock copolymer poly(ethylene glycol)-block-poly(L-lysine) (PEG-b-PLys), tetrakis(4-sulfonatophenyl)porphinato cobalt(II) (Co(II)TPPS), a heptapeptide (Cys-His-His-His-His-His-His) and heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin (TM-β-CD). Co(II)TPPS was encapsulated into the cavities of TM-β-CDs driven by the host–guest interaction so that the irreversible formation of a μ-oxo-dimer of Co(II)TPPS can be effectively prevented. The imidazole groups of the heptapeptide were selected as good axial ligands coordinating to the centric cobalt of Co(II)TPPS, which subtly constituted the five-coordinated precursor serving as an active functional centre for oxygen binding. The sixth position of Co(II)TPPS can bind oxygen. Furthermore, the host–guest inclusion (TM-β-CD/Co(II)TPPS) was loaded into the hydrophobic core of the complex micelle and tightly fixed with PLys chains. The hydrophilic PEG blocks stretched in the aqueous solution constitute the shells which stabilize the structure of the complex micelle as well as impart the complex micelle sufficient blood circulation time. Moreover, the complex micelle exhibited excellent biocompatibility and cellular uptake. Therefore, the rationally designed amphiphilic structure can work as promising artificial O₂ carriers in vivo. Potentially, the complex micelle can be expected to change the anaerobic microenvironment and find applications in the repair of the cells damaged by cellular hypoxia.