Qiao Song

Chiral polymers hold great potential in biomimics and synthetic materials, owing to their unique properties associated with diverse forms of chirality. Although polymers with central chirality are well‐developed, axially chiral polymers remain underexplored, presumably due to the lack of efficient synthetic methods. Herein, we develop a new strategy of asymmetric C–H activation polymerization for constructing axially chiral side chain polymers from prochiral monomers. Based on sequential Co‐catalyzed C–H activation/annulation, the polymerization proceeds in a quantitative manner, affording a range of axially chiral side chain polymers with high molecular weights, diverse chemical structures and tunable chiroptical properties. Furthermore, by stereochemical analysis of carefully designed model reactions, we have unambiguously confirmed excellent atroposelectivity control over the polymerization. This efficient strategy, which represents a significant advance in polymer synthesis, could open up new avenues for the design of chiral polymer materials with desirable properties.

Chiral polymers hold great potential in biomimics and synthetic materials, owing to their unique properties associated with diverse forms of chirality. Although polymers with central chirality are well‐developed, axially chiral polymers remain underexplored, presumably due to the lack of efficient synthetic methods. Herein, we develop a new strategy of asymmetric C–H activation polymerization for constructing axially chiral side chain polymers from prochiral monomers. Based on sequential Co‐catalyzed C–H activation/annulation, the polymerization proceeds in a quantitative manner, affording a range of axially chiral side chain polymers with high molecular weights, diverse chemical structures and tunable chiroptical properties. Furthermore, by stereochemical analysis of carefully designed model reactions, we have unambiguously confirmed excellent atroposelectivity control over the polymerization. This efficient strategy, which represents a significant advance in polymer synthesis, could open up new avenues for the design of chiral polymer materials with desirable properties.

Organic photosensitizers (PSs) are a class of photoactive molecules capable of generating reactive oxygen species (ROS) upon light irradiation, with their performance largely governed by their excited‐state properties. While continuous efforts have focused on developing new PSs through molecular design, supramolecular chemistry provides a complementary and versatile platform for regulating the excited states of conventional PSs to construct novel supramolecular PSs. In this review, we summarize recent supramolecular engineering strategies that not only improve key properties, such as solubility, biocompatibility, ROS generation capability, and photostability, but also introduce advanced functionalities, including stimuli‐responsive activation, assembly‐induced emergence of photosensitizing activity, and regulation of Type I/Type II photodynamic pathways. Moreover, the applications of supramolecular PSs in diverse photochemical and biomedical fields are comprehensively overviewed, highlighting their unique advantages over small‐molecule PSs. We hope that this review will bring more inspiration and possibilities for advancing the field of supramolecular PSs and inspire future innovations in supramolecular photochemistry and photomedicine.

Room‐temperature phosphorescence (RTP) from purely organic materials holds great potential for optoelectronic and bioimaging applications; however, its realization remains challenging due to inefficient intersystem crossing (ISC) and rapid nonradiative decay. Herein, we present an effective strategy to activate and enhance RTP in heavy‐atom‐free chromophores through external heavy‐atom engineering (HAE). By dispersing these chromophores within hydrophobic halogen‐rich polymer matrices, external HAE is employed to enhance spin–orbit coupling and promote efficient ISC. The generality of this strategy is demonstrated across a series of polycyclic aromatic hydrocarbons and further extended to other heterocyclic chromophores, affording bright (phosphorescence quantum yields up to 61.6%) and long‐lived (phosphorescence lifetimes up to 273 ms) RTP materials under ambient conditions, with emission wavelengths spanning from 500 to 700 nm. This supramolecular approach circumvents the need for covalent introduction of heavy atoms to the luminophores, thereby preserving their intrinsic photophysical properties while unlocking desirable triplet‐state emissions. Overall, the current external HAE strategy provides a versatile platform for the construction of high‐performance organic RTP materials, offering new insights into the design principles of organic RTP systems and broadening the material landscape for optoelectronic and bioimaging applications.

Room‐temperature phosphorescence (RTP) from purely organic materials holds great potential for optoelectronic and bioimaging applications; however, its realization remains challenging due to inefficient intersystem crossing (ISC) and rapid nonradiative decay. Herein, we present an effective strategy to activate and enhance RTP in heavy‐atom‐free chromophores through external heavy‐atom engineering (HAE). By dispersing these chromophores within hydrophobic halogen‐rich polymer matrices, external HAE is employed to enhance spin–orbit coupling and promote efficient ISC. The generality of this strategy is demonstrated across a series of polycyclic aromatic hydrocarbons and further extended to other heterocyclic chromophores, affording bright (phosphorescence quantum yields up to 61.6%) and long‐lived (phosphorescence lifetimes up to 273 ms) RTP materials under ambient conditions, with emission wavelengths spanning from 500 to 700 nm. This supramolecular approach circumvents the need for covalent introduction of heavy atoms to the luminophores, thereby preserving their intrinsic photophysical properties while unlocking desirable triplet‐state emissions. Overall, the current external HAE strategy provides a versatile platform for the construction of high‐performance organic RTP materials, offering new insights into the design principles of organic RTP systems and broadening the material landscape for optoelectronic and bioimaging applications.

Twisted intramolecular charge transfer (TICT) dyes are promising candidates for bioimaging and sensing due to their environment‐sensitive fluorescence and large Stokes shifts. However, their inherently low fluorescence quantum yields in aqueous media have limited their practical applications. Here, we present a general supramolecular strategy to transform a broad range of TICT dyes into bright fluorophores with large Stokes shifts. By noncovalently dispersing the dyes into the rigid microdomain of a cyclic peptide‐based supramolecular scaffold in water, the formation of the non‐radiative TICT state is effectively suppressed. The resulting supramolecular TICT dyes exhibit dramatically enhanced fluorescence quantum yields (up to 42.3%), while preserving large Stokes shifts of up to 107 nm. Particularly, supramolecular TICT dyes emitting in the NIR region display excellent photostability, enabling applications in long‐term bioimaging and single‐excitation multi‐color imaging in live cells. This work offers a versatile and modular supramolecular approach to generate high‐performance fluorophores from otherwise low‐ or non‐emissive TICT dyes, greatly broadening their potential in biological and optical applications.

Twisted intramolecular charge transfer (TICT) dyes are promising candidates for bioimaging and sensing due to their environment‐sensitive fluorescence and large Stokes shifts. However, their inherently low fluorescence quantum yields in aqueous media have limited their practical applications. Here, we present a general supramolecular strategy to transform a broad range of TICT dyes into bright fluorophores with large Stokes shifts. By noncovalently dispersing the dyes into the rigid microdomain of a cyclic peptide‐based supramolecular scaffold in water, the formation of the non‐radiative TICT state is effectively suppressed. The resulting supramolecular TICT dyes exhibit dramatically enhanced fluorescence quantum yields (up to 42.3%), while preserving large Stokes shifts of up to 107 nm. Particularly, supramolecular TICT dyes emitting in the NIR region display excellent photostability, enabling applications in long‐term bioimaging and single‐excitation multi‐color imaging in live cells. This work offers a versatile and modular supramolecular approach to generate high‐performance fluorophores from otherwise low‐ or non‐emissive TICT dyes, greatly broadening their potential in biological and optical applications.

Heavy‐atom‐free photosensitizers (PSs) offer advantages such as efficient generation of reactive oxygen species (ROS), low dark cytotoxicity, good photostability, and high biocompatibility. Although the development of new PSs through organic synthesis has been a focus of active research, supramolecular chemistry offers a complementary pathway. This study presents a versatile supramolecular strategy to convert conventional fluorophores into heavy‐atom‐free PSs using a cyclic peptide‐based scaffold that densely assembles fluorophore moieties. Results demonstrate that supramolecular PSs constructed from four synthetic fluorophore types—cyanines, coumarins, rhodamines, and BODIPYs—exhibit a remarkable enhancement in ROS generation efficiency, attributed to the increased intersystem crossing efficiency induced by self‐assembly. Moreover, these supramolecular PSs function as visible‐light photocatalysts, efficiently regenerating NAD ⁺ from NADH. The densely packed polymer shell further shields enzymes from ROS‐induced deactivation, thereby facilitating the development of robust photoenzyme catalytic systems. This study not only enriches the design methodology of heavy‐atom‐free PSs, but also paves the way for eco‐friendly photobiocatalytic systems.

Heavy‐atom‐free photosensitizers (PSs) offer advantages such as efficient generation of reactive oxygen species (ROS), low dark cytotoxicity, good photostability, and high biocompatibility. Although the development of new PSs through organic synthesis has been a focus of active research, supramolecular chemistry offers a complementary pathway. This study presents a versatile supramolecular strategy to convert conventional fluorophores into heavy‐atom‐free PSs using a cyclic peptide‐based scaffold that densely assembles fluorophore moieties. Results demonstrate that supramolecular PSs constructed from four synthetic fluorophore types—cyanines, coumarins, rhodamines, and BODIPYs—exhibit a remarkable enhancement in ROS generation efficiency, attributed to the increased intersystem crossing efficiency induced by self‐assembly. Moreover, these supramolecular PSs function as visible‐light photocatalysts, efficiently regenerating NAD ⁺ from NADH. The densely packed polymer shell further shields enzymes from ROS‐induced deactivation, thereby facilitating the development of robust photoenzyme catalytic systems. This study not only enriches the design methodology of heavy‐atom‐free PSs, but also paves the way for eco‐friendly photobiocatalytic systems.