Ben Zhong Tang
Luminescence and Fluorescent Materials
Hong Kong University of Science and Technology
About
Research focus
Luminescence and Fluorescent Materials
Impact
4,152 pubs · 234,681 cites · h-index 208
Affiliations
Publications
Original Research
OCT 29TanAggregate
Growth Arrest‐Specific 6‐Enriched Near‐Infrared‐II Nanodecoys for Chemo‐Photothermal Therapy and Preemptive Inhibition of Lung Metastasis in Nasopharyngeal Carcinoma
Nasopharyngeal carcinoma (NPC) is a highly aggressive malignancy with poor prognosis, and preventing its metastasis remains a major clinical challenge. In this work, we developed a series of biomimetic nanodecoys (NDs) capable of precise diagnosis and effective treatment of NPC while concurrently preventing lung metastasis. The NDs were synthesized via precipitation polymerization to form the thermo‐/pH‐responsive poly( N ‐isopropylacrylamide‐co‐acrylic acid) nanogels (PA NGs), followed by the encapsulation of a newly developed aggregation‐induced emission luminogen (AIEgen) for strong near‐infrared (NIR) fluorescence imaging (FLI) and remarkable photothermal therapy (PTT) performance. In combination with the chemotherapeutic drug doxorubicin (Dox), these NDs achieved effective chemo‐photothermal combinatorial therapy. Triggered by the acidic tumor microenvironment, the NDs could release Dox, and this release could be further accelerated under NIR irradiation. Moreover, we demonstrated that growth arrest‐specific 6 (Gas6)‐camouflaged NDs (PND@Gas6(+) NDs) could function as a prophylactic agent to bind the Axl receptor in both tumor and lung metastatic niches, thereby preemptively blocking the Gas6/Axl axis and preventing tumor deterioration and metastasis. This study presents an innovative strategy that integrates real‐time NIR‐II monitoring and synergistic chemo‐PTT therapy for NPC, while also providing a rational design for metastasis inhibition, offering substantial promise for improving NPC treatment.
Original Research
OCT 29ChenMacromolecules
Multicomponent Polymerization of Carbamates, Chlorodiphenylphosphine, and Aromatic Aldehyde toward Poly(α-carbamatephosphineoxide)s
The exploration of phosphorus-containing polymer structures and development of their facile and efficient synthetic approaches are of great challenge and significance in polymer science. In this work, an efficient multicomponent polymerization of carbamates, chlorodiphenylphosphine, and aromatic aldehyde was developed for the facile access to a new group of phosphorus-containing polymers—poly(α-carbamatephosphineoxide)s. The polymerization went efficiently in 1,4-dioxane at 70 °C, without any catalyst or additive, producing poly(α-carbamatephosphineoxide)s with well-defined chemical structures, satisfying molecular weights (Mns up to 17,500 g/mol), and high yields (up to 91%). These poly(α-carbamatephosphineoxide)s possess abundant intermolecular hydrogen bonds, good thermal stability, and aggregation-induced emission property. The chlorophosphine-involving multicomponent polymerization could hence provide facile access to new phosphorus-containing polymer structures, promoting the advancement of phosphorus-containing polymer materials.
Original Research
OCT 28HuAdvanced Functional Materials
Ultrasensitive Wash‐Free Immunoassay Via Constructing Ultrabright AIE Beads Based on Dual‐FRET Process and Cycling Activated Mechanism
The luminescent oxygen channeling immunoassay (LOCI) is a homogeneous, washing‐free bioanalytical platform renowned for its high convenience and multiple detection capabilities in biomarker detection, but the widespread adoption of LOCI has been constrained by the limited sensitivity originated from the poor luminescence intensity of classical acceptor beads. Herein, we report a reference strategy of constructing ultrabright acceptor beads based on dual‐fluorescence resonance energy transfer (FRET) process and cycling activated mechanism via inserting aggregation‐induced emission (AIE) photosensitive dyes. This design enables the conversion of otherwise wasted energy in conventional Europium‐based microparticles (EuSNPs) luminescence system into luminescence via reactive oxygen species (ROS) activation. By introducing the AIE‐active bridge fluorophore (AG) to acceptor microparticles (TASNPs), the PLQY was remarkably enhanced to 56% compared to AG‐free systems. Based on the established LOCI platform with inserting photosensitive microparticles, an ultrasensitive detection limit of 0.36 pg·mL − 1 toward Interleukin‐6 (IL‐6) is achieved, representing 64‐fold improvement over EuSNPs. The assay could be completed within 5 min and exhibite excellent repeatability (CV < 10%). This work introduces a versatile and efficient strategy‐through synergistic 1 O 2 cycling and dual‐FRET enhancement for advancing the performance of wash‐free luminescent immunoassays, offering a promising pathway toward next‐generation clinical diagnostics.
Original Research
OCT 28XuAggregate
From Benzene to [3]Radialene: Topological Engineering of Pure Hydrocarbons for Long‐Wavelength Aggregation‐Induced Emission Luminogens
Due to the topological divergence between [3]radialene and benzene, hexaphenyl[3]radialene exhibits a dramatic bathochromic shift in emission (619 nm) with a Stokes shift >150 nm, which is distinct from its structural analogue hexaphenylbenzene. Our mechanistic analyses revealed the localized bond rearrangement and moderate short‐range charge transfer, which lead to its long‐wavelength emission and enhanced aggregation‐induced emission character. Ring‐locked derivatives, tridibenzocycloheptadiene[3]radialene and tridimethylanthracene[3]radialene (TAR), were synthesized, exhibiting tunable emission wavelength (507–685 nm) and high crystalline‐state quantum yields (up to 49.2%). Finally, the potential of TAR for lysosome‐targeting bioimaging was demonstrated. Our results establish the [3]radialene backbone as a robust hydrocarbon scaffold for high‐performance, long‐wavelength emitters.
Original Research
OCT 28WANGEnvironmental Science & Technology
Novel NIR-II Imaging Reveals Gut-First, Brain-Later Inorganic Mercury Signals with Structural Injury in Zebrafish
Mercury (Hg) neurotoxicity has generally been assessed by organic methylmercury, whereas inorganic mercury [Hg(II)] is often considered less likely to cause direct brain exposure. Conventional approaches cannot resolve the in vivo spatiotemporal distribution of Hg(II) across tissues. In this study, we first developed an Hg(II)-responsive aggregation-induced emission sensor for second near-infrared (NIR-II) fluorescence imaging, which was then employed to track Hg(II) signals in live zebrafish. The sensor produced enhanced NIR-II signals in the presence of Hg(II), allowing low-background, noninvasive, and real-time imaging. We observed that Hg(II)-responsive sensor signals first appeared in the intestinal region and later increased in the brain region, revealing an intestine-first and brain-later temporal pattern in living zebrafish. During a 48-h continuous exposure followed by depuration, brain-region Hg(II)-responsive sensor fluorescence increased with exposure concentration and time and remained detectable during the depuration phase. Expansion microscopy further showed that low-dose Hg(II) exposure reduced the brain cell density and average cell size, and disrupted the local tissue organization. These results provided in vivo evidence of Hg(II)-responsive sensor in the brain region and its association with structural brain injury during development. Thus, inorganic Hg should also be considered in the assessments of developmental brain exposure and neural structural injury.
Original Research
OCT 27ChenNankai University
Dual-Function Organic Emitters for Plastic Scintillators Enabled by Integration of Photocatalytic Controlled Radical Polymerization and Sensitive X-Ray Detection
Organic scintillators are attractive for X-ray detection and imaging because of their solution processability and compatibility with large-area fabrication. However, their development is limited by the trade-off between X-ray attenuation and photoluminescence quantum yield (PLQY), as well as by the lack of mild fabrication methods for plastic scintillator screens. Herein, we report a brominated donoracceptor–donor molecular platform with hybridized local and charge-transfer (HLCT) character that addresses both challenges. Peripheral bromination of a benzo[c][1,2,5]oxadiazole-based scaffold produces a pronounced anti-heavy-atom effect, simultaneously enhancing X-ray attenuation and PLQY. This strategy is extended through chalcogen substitution to afford BOTBr, BTTBr, and BSeTBr, among which BTTBr shows the best overall performance, delivering a PLQY of 77%, a light yield of 37,851 photons MeV-1, and a detection limit of 54 nGy s-1. Notably, BTTBr also acts as a photocatalyst for photoinitiated atom transfer radical polymerization (PhotoATRP), enabling the in situ fabrication of transparent and uniform poly(methyl methacrylate) scintillator screens under mild conditions. The resulting screens afford high-resolution X-ray imaging with a spatial resolution of 13.2 lp mm-1. This work establishes an anti-heavy-atom-effect strategy for dual-functional scintillatorphotocatalyst materials and provides a light-driven route to integrated plasticscintillator fabrication.
Original Research
OCT 23LiAccounts of Chemical Research
Evolution of Aggregation-Induced Emission Materials in Cancer Diagnosis and Therapy: Toward Clinical Translation
Conspectus As one of the most formidable threats to human health, cancer demands technologies that can sensitively detect malignancies, precisely guide intervention, adapt to dynamic disease states, and support clinical decision-making. Phototheranostics based on organic fluorophores have shown great promise in cancer management owing to their tunable structural design, tumor-targeting capability, real-time imaging output, and biocompatibility with diverse therapeutic modalities. However, conventional fluorophores often suffer from aggregation-caused quenching in concentrated or biological aggregate states, leading to weakened signals, insufficient sensitivity, and limited therapeutic efficacy. The discovery of aggregation-induced emission (AIE) provides a conceptually distinct solution to this problem. AIE materials are weakly emissive in the molecularly dispersed state but become highly luminescent upon aggregation, thereby turning aggregation from a detrimental process into a useful photophysical mechanism. By precisely controlling molecular motion, AIE materials can exhibit advantages including high signal-to-noise ratio, large Stokes shifts, and excellent photostability, making them a versatile molecular toolbox for tumor-oriented phototheranostic systems. Over the past two decades, they have evolved beyond simple fluorescent probes into integrated platforms for cancer theranostics. In this Account, we propose a concept-driven framework, termed AIMS (Analyze-Intervene-Modulate-Select), to organize the evolution of AIE materials in cancer diagnosis and therapy according to their distinctive roles within cancer management. The first generation, “Analyze”, refers to AIE materials used mainly as diagnostic tools. These systems enable sensitive detection of tumor-associated biomarkers, in vivo lesion visualization, and multimodal intraoperative identification. The second generation, “Intervene”, generates all-in-one theranostic platforms that couple imaging with phototherapy, facilitating radiotherapy sensitization, immune activation, or postoperative control. The third generation, “Modulate”, describes intelligent and adaptive AIE platforms that respond to therapy-induced stress, microenvironmental shifts, or dynamic biological feedback during treatment, transforming static theranostics into systems capable of modulating therapeutic trajectories. The emerging fourth generation, “Select”, represents a data-driven paradigm linking the design of AIE materials with artificial intelligence, multiomics, patient stratification, model selection, and indication prioritization. Through AIMS, we organize the accumulated capabilities of AIE materials around four functional roles. By clarifying which role is most relevant to a given application, AIMS guides future research in prioritizing design objectives, integrating the functions needed for the intended task, and matching material innovation to specific needs in cancer management.
Original Research
OCT 23YouJournal of the American Chemical Society
Finding the Sweet Spot: Isomerization Strategy Enables Balanced Energy Dissipation of NIR-II AIEgens for “One-for-All” Tumor Phototheranostics
Abstract “One-for-all” phototheranostics with the second near-infrared window (NIR-II) emission have garnered great enthusiasm for seamlessly integrating superb imaging and high-efficiency therapy into a single formula. However, it is still a nontrivial conundrum to achieve balanced excited-state energy dissipation to guarantee high NIR-II brightness, photothermal conversion, and reactive oxygen species (ROS) generation. As a powerful tool for balancing radiative and nonradiative decays, aggregation-induced emission luminogens (AIEgens) are emerging as a promising frontier in developing “one-for-all” phototheranostic agents, while their phototheranostic performance needs to be further improved. In this contribution, we designed and synthesized two positional isomers, 5BT-PBPT and 6BT-PBPT, by attaching donors at the 5- and 6-positions of the benzo[b]thiophene (BT) segment, respectively, to investigate the effect of positional isomerism on the phototheranostic performance of NIR-II AIEgens. Interestingly, both experimental and computational results demonstrate that the isomerization affords great strength in tuning energy levels, structural conformations, aggregation behaviors, and excited-state energy dissipation. Consequently, a sweet spot for fully utilizing excitation energy was achieved in 5BT-PBPT nanoparticles (NPs), which exhibited not only strong NIR absorption but also high NIR-II fluorescence brightness, strong ROS production, and excellent photothermal conversion efficiency (η). Benefiting from this, 5BT-PBPT NPs afforded superior performance in the “one-for-all” phototheranostics for orthotopic breast tumor treatment. This study fully demonstrates the effectiveness of the isomeric engineering strategy in comprehensively improving the phototheranostic capabilities of NIR-II AIEgens and thereby provides an effective approach for the construction of high-performance NIR-II “one-for-all” phototheranostic agents.
Original Research
OCT 23LouFlexMat.
Tailoring hot‐exciton emitter via an accelerated reverse intersystem crossing process for deep‐blue organic light‐emitting diodes with an external quantum efficiency approaching 16% at 1000 cd m −2 and a CIE y of 0.027
Achieving high‐efficiency, saturated‐color, and stable deep‐blue organic light‐emitting diodes (OLEDs) is essential for ultrahigh‐definition displays; however, it still faces challenges due to the intrinsic wide band gap of emitters. Here, we report a deep‐blue hot‐exciton materials, 2TPA‐SAF‐CN , exhibiting typical hybridized local‐excited and charge‐transfer characteristics. By dividing 2TPA‐SAF‐CN into two fragments (short‐axis and long‐axis), it is found that the long‐axis enables 2TPA‐SAF‐CN deep‐blue emission and a high photoluminescence quantum yield of 93.2%, while the short‐axis accelerates the high‐lying reverse intersystem crossing process to a rate of 4.40 × 10 9 s −1 and improves the exciton utilization efficiency of 2TPA‐SAF‐CN by over 10%. As a result, a series of OLEDs based on 2TPA‐SAF‐CN is prepared, achieving a small CIE y coordinate of 0.027 with a high external quantum efficiency of 15.7% and negligible efficiency roll‐off at 1000 cd m −2 . The sensitized OLED of 2TPA‐SAF‐CN exhibits intense deep‐blue emission peaking at 452 nm with a half‐width of 22 nm and CIE y coordinate (0.048) close to BT.2020 standard, corresponding to an LT 85 of ≈626 h at an initial luminance of 100 cd m −2 . To the best of our knowledge, it is the leading performance of deep‐blue fluorescent OLED.
Original Research
OCT 22LiuJournal of the American Chemical Society
Perfluoroalkyl Anion Strategy to Construct Anion–π+ Type NIR-II Phototheranostic Agents for Enhanced Tumor Immunotherapy via Necroptosis/Ferroptosis
Anion-π+ photosensitizers (PSs) possess exceptional reactive oxygen species (ROS) generation and precise organelle targeting that could disrupt intracellular metabolic homeostasis and induce nonapoptotic cell death, offering unique advantages in overcoming immunosuppression. However, previous reports mainly focused on modifying the π+ core but often overlooked the crucial role of anions. Herein, we present a facile perfluoroalkyl anion strategy to modulate the fluorescence intensity and ROS generation capacity of anion-π+ PSs. Perfluorobutanesulfonate (PFB) anions with a single-sided perfluoroalkyl chain and bis(perfluorobutylsulfonyl)amide (BPFB) anions bearing double-sided perfluoroalkyl chains were employed to readily replace the hexafluoroantimonate (HFA) counterions in A/HFA and TPQ/HFA, yielding A/PFB, TPQ/PFB, A/BPFB, and TPQ/BPFB. Compared to the incorporated PFB anions, the BPFB anions more effectively restrict intramolecular motion through anion-π+ and van der Waals interactions, thereby significantly enhancing the fluorescence intensity of the phototheranostic agents─by 50.8-fold and 4.2-fold in A/BPFB nanoparticles (NPs) and TPQ/BPFB NPs compared to their HFA analogues, respectively. Concurrently, TPQ/BPFB NPs with second near-infrared emission demonstrated superior ROS generation, excellent mitochondrial targeting, and remarkable resistance to photobleaching. Strikingly, TPQ/BPFB NPs can activate both necroptosis and ferroptosis under irradiation, triggering a robust systemic immune response. Additionally, the lipophilicity granted by BPFB enables TPQ/BPFB NPs to infiltrate deeper into tumors, guaranteeing a more extensive photodynamic therapy with a 95% tumor suppression rate. Crucially, the immune memory triggered by TPQ/BPFB NPs effectively decreases the occurrence of lung metastases. Altogether, the perfluoroalkyl anion strategy proposed in this study offers new insights for developing potent anion-π+ PSs.
Original Research
OCT 19ZengAdvanced Optical Materials
Constructing Efficient Narrow‐Spectrum Circularly Polarized Organic Light‐Emitting Diodes with Near‐Ultraviolet Chiral Assistant Dopants
Ultraviolet (UV) and near‐ultraviolet (NUV) chiral materials are viable candidates as assistant dopants for constructing narrow‐spectrum circularly polarized organic light‐emitting diodes (CP‐OLEDs), which can be applied in next‐generation three‐dimensional displays. However, UV/NUV materials that fully satisfy the stringent requirements for chiral assistant dopants remain scarce. Herein, a pair of enantiomers, ( S )/( R )‐OBNPCN‐SFIAC, were designed, synthesized and characterized, which exhibit efficient NUV circularly polarized luminescence (CPL) with high‐level reverse intersystem crossing (hRISC) properties. They function efficiently as emitters in non‐doped and doped CP‐OLEDs, providing maximum external quantum efficiencies ( EQE max s) of 6.72% and 7.47%, respectively, along with absolute electroluminescence dissymmetry factors (| g EL |s) of up to 7.35 × 10 −3 . Also, they can serve as assistant dopants in narrow‐spectrum blue, green and orange multi‐resonance thermally activated delayed fluorescence (MR‐TADF) OLEDs, furnishing impressive EQE max s and | g EL |s of 38.65% and 8.67 × 10 −3 , respectively. To the best of our knowledge, the above results are amongst the best of the reported narrow‐spectrum CP‐OLEDs so far.
Original Research
OCT 21XiongJournal of the American Chemical Society
Core–Shell Structures Govern Through-Space Interactions in Triblock Copolymers toward Deep-Red Clusteroluminescence
Green fluorescent protein (GFP) and its derivatives have transformed biological imaging, yet fluorophores that simultaneously combine biocompatibility, structural programmability, and intrinsic long-wavelength luminescence remain scarce. Here, we develop a controllable one-pot polymerization strategy to construct nonconjugated triblock copolymers that can self-assemble into core–shell clusters. By modulating the hydrophilic–hydrophobic balance of copolymer chains, the core-to-shell ratio, chain packing, and electronic through-space interactions within the clusters can be precisely regulated, enabling tunable clusteroluminescence (CL) that extends to the deep-red and near-infrared emission region. Ultrafast spectroscopy further uncovers the excited-state dynamics of these core–shell clusters and reveals how the coupled evolution of electronic states and structures governs CL generation. Moreover, the core–shell clusters enable in vivo angiography under two-photon excitation, highlighting their potential as biocompatible nanofluorophores. These findings establish core–shell engineering as a general design principle for efficient clusteroluminogens, deepen the mechanistic understanding of CL, and pave the way for next-generation nanofluorescence technologies.
Original Research
OCT 16SongAngewandte Chemie
Positional Isomerism Reveals Intrinsic Decoupling of Structural Relaxation and Vibrational Frequency in MR‐TADF Emitters
The pursuit of high‐color‐purity organic light‐emitting diodes (OLEDs) has spurred the development of multiple resonance (MR) emitters. Yet a long‐standing assumption in the field holds that minimizing excited‐state structural displacement (Δ Q ) is essential for achieving narrow emission bandwidth. Here we challenge this notion by demonstrating that Δ Q and molecular vibrational frequency ( ω ) act as independent, rather than coupled, determinants of the emission full width at half maximum (FWHM). Through systematic ortho ( o DB‐BN), meta ( m DB‐BN), and para ( p DB‐BN) positional isomerism of a sterically bulky dimesitylboryl acceptor on an archetypal MR scaffold, we reveal that small Δ Q reduces the Stokes shift but does not guarantee narrow FWHM; instead, low ω emerges as the decisive factor. The meta‐substituted isomer, despite exhibiting the smallest Δ Q , displays the broadest FWHM owing to a prominent low‐frequency torsional vibration. Conversely, the ortho ‐ and para ‐isomers retain ultranarrow emission despite pronounced molecular distortion. The resulting OLEDs achieve excellent external quantum efficiencies of up to 33.3% with suppressed roll‐off, and pDB‐BN delivers a remarkable luminance of 109 600 cd m −2 . This work provides an alternative perspective on the design of narrowband emitters, suggesting that controlling vibrational coupling, in addition to minimizing structural displacement, is a valuable consideration in molecular engineering.
Original Research
OCT 16XiaoJournal of the American Chemical Society
Chirality-Directed Molecular Weaving
Weaving molecular strands in a manner akin to macroscale fabrics is considered a highly promising strategy for the development of novel polymeric materials. However, existing molecular weaving strategies rely on metal templates or solvent assistance for topological control, which limits molecular weaving to specific conditions. Here, we present a new molecular weaving strategy based on chirality-directed assembly. It can be used in the construction of two-dimensional molecularly woven polymers in various solvents and at different temperatures, all without the use of metal templates or solvent assistance. Furthermore, leveraging the characteristic undulating structure of the woven topology, this strategy provides a unique pathway for tuning the porous separation performance and mechanical properties of molecularly woven materials. These advancements will expedite molecular weaving technology with unprecedented properties.
Original Research
OCT 14YAngewandte Chemie
Hierarchically Molecular Programming of Antiparallel H‑Aggregates for NIR Type I Photochemistry
Developing near‐infrared (NIR) photosensitizers with effective type I reactive oxygen species (ROS) generation remains challenging. H‑aggregates promote triplet formation and charge transfer, but often suffer from substantial absorption blueshifts and excessive thermal deactivation that compromise photosensitization efficacy. Herein, a hierarchically molecular programming strategy is proposed to construct minimal‐blueshift H‐aggregates as robust NIR type I photosensitizers. Primary engineering via π‐bridge extension and acceptor strengthening within a twisted–planar donor–π–acceptor scaffold endows the antiparallel H‐packed TNCF3‐C6‐C2 aggregates with strong NIR absorption (749 nm) and predominant type I ROS generation. Secondary side‐chain programming further regulates the H‐packing and intermolecular electronic interactions to enhance type I ROS generation. Structural, photochemical and theoretical investigations revealed that the branched side chains promote molecular planarization and robust H‑packing, thereby enhancing intersystem crossing and intermolecular charge transfer. The optimized TNCF3‐2C6 with symmetric branched side chain exhibited minimal absorption blueshift (20 nm) upon H‐aggregation, enhanced NIR harvesting ability and a further ∼2‐fold enhancement in ROS generation over the initial TNCF3‐C6‐C2 H‐aggregates, thereby delivering potent tumor inhibition both in vitro and in vivo. Built upon the hierarchical programming of H‐aggregates, this work establishes a supramolecular design paradigm toward modulating excitonic coupling and excited‐state dynamics for high‐performance photo‐functional materials.
Original Research
OCT 14LiAngewandte Chemie
Redirecting Excited‐State Energy Flow Through Programmed Supramolecular Confinement in Twisted Photosensitizers
Programmed supramolecular confinement is introduced as a physical strategy to investigate aggregation‐enhanced reactive oxygen species (ROS) generation in twisted intramolecular charge transfer (TICT)‐active twisted photosensitizers without changing the conjugated photosensitizing unit. In this design, TICT functions as a confinement‐sensitive regulator of excited‐state energy dissipation, while cell membranes (CM) serve as supramolecular platforms that confine photosensitizers within their compact phospholipid bilayer architectures. Through alkyl‐chain engineering, the obtained photosensitizers exhibit similar photophysical properties but tunable interactions with phospholipids, resulting in programmed confinement states within CMs. Experimental and theoretical studies reveal that supramolecular confinement suppresses TICT‐mediated non‐radiative relaxation by reducing excitation‐induced donor‐acceptor torsional change and restricting intramolecular rotation, thereby redirecting excited‐state energy flow toward radiative emission and intersystem crossing‐mediated ROS generation. Accordingly, stronger confinement induces higher enhancements in fluorescence and ROS generation, establishing a supramolecular confinement‐dependent correlation among TICT restriction, fluorescence, and ROS generation. Finally, the optimized CM‐photosensitizer assemblies are applied as photodynamic systems and display effective performance in cancer immunotherapy. By coupling TICT restriction with ROS generation, this work establishes supramolecular confinement as a physical strategy for redirecting excited‐state energy flow and provides direct insight into how aggregation enhances ROS generation in twisted photosensitizers.
Original Research
OCT 14LiAngewandte Chemie International Edition
Redirecting Excited‐State Energy Flow Through Programmed Supramolecular Confinement in Twisted Photosensitizers
Programmed supramolecular confinement is introduced as a physical strategy to investigate aggregation-enhanced reactive oxygen species (ROS) generation in twisted intramolecular charge transfer (TICT)-active twisted photosensitizers without changing the conjugated photosensitizing unit. In this design, TICT functions as a confinement-sensitive regulator of excited-state energy dissipation, while cell membranes (CM) serve as supramolecular platforms that confine photosensitizers within their compact phospholipid bilayer architectures. Through alkyl-chain engineering, the obtained photosensitizers exhibit similar photophysical properties but tunable interactions with phospholipids, resulting in programmed confinement states within CMs. Experimental and theoretical studies reveal that supramolecular confinement suppresses TICT-mediated non-radiative relaxation by reducing excitation-induced donor-acceptor torsional change and restricting intramolecular rotation, thereby redirecting excited-state energy flow toward radiative emission and intersystem crossing-mediated ROS generation. Accordingly, stronger confinement induces higher enhancements in fluorescence and ROS generation, establishing a supramolecular confinement-dependent correlation among TICT restriction, fluorescence, and ROS generation. Finally, the optimized CM-photosensitizer assemblies are applied as photodynamic systems and display effective performance in cancer immunotherapy. By coupling TICT restriction with ROS generation, this work establishes supramolecular confinement as a physical strategy for redirecting excited-state energy flow and provides direct insight into how aggregation enhances ROS generation in twisted photosensitizers.
Original Research
OCT 15SongAngewandte Chemie International Edition
Positional Isomerism Reveals Intrinsic Decoupling of Structural Relaxation and Vibrational Frequency in MR‐TADF Emitters
The pursuit of high‐color‐purity organic light‐emitting diodes (OLEDs) has spurred the development of multiple resonance (MR) emitters. Yet a long‐standing assumption in the field holds that minimizing excited‐state structural displacement (Δ Q ) is essential for achieving narrow emission bandwidth. Here we challenge this notion by demonstrating that Δ Q and molecular vibrational frequency ( ω ) act as independent, rather than coupled, determinants of the emission full width at half maximum (FWHM). Through systematic ortho ( o DB‐BN), meta ( m DB‐BN), and para ( p DB‐BN) positional isomerism of a sterically bulky dimesitylboryl acceptor on an archetypal MR scaffold, we reveal that small Δ Q reduces the Stokes shift but does not guarantee narrow FWHM; instead, low ω emerges as the decisive factor. The meta‐substituted isomer, despite exhibiting the smallest Δ Q , displays the broadest FWHM owing to a prominent low‐frequency torsional vibration. Conversely, the ortho ‐ and para ‐isomers retain ultranarrow emission despite pronounced molecular distortion. The resulting OLEDs achieve excellent external quantum efficiencies of up to 33.3% with suppressed roll‐off, and pDB‐BN delivers a remarkable luminance of 109 600 cd m −2 . This work provides an alternative perspective on the design of narrowband emitters, suggesting that controlling vibrational coupling, in addition to minimizing structural displacement, is a valuable consideration in molecular engineering.
Original Research
OCT 13YAngewandte Chemie International Edition
Hierarchically Molecular Programming of Antiparallel H‑Aggregates for NIR Type I Photochemistry
Developing near-infrared (NIR) photosensitizers with effective type I reactive oxygen species (ROS) generation remains challenging. H‑aggregates promote triplet formation and charge transfer, but often suffer from substantial absorption blueshifts and excessive thermal deactivation that compromise photosensitization efficacy. Herein, a hierarchically molecular programming strategy is proposed to construct minimal-blueshift H-aggregates as robust NIR type I photosensitizers. Primary engineering via π-bridge extension and acceptor strengthening within a twisted-planar donor-π-acceptor scaffold endows the antiparallel H-packed TNCF3-C6-C2 aggregates with strong NIR absorption (749 nm) and predominant type I ROS generation. Secondary side-chain programming further regulates the H-packing and intermolecular electronic interactions to enhance type I ROS generation. Structural, photochemical and theoretical investigations revealed that the branched side chains promote molecular planarization and robust H‑packing, thereby enhancing intersystem crossing and intermolecular charge transfer. The optimized TNCF3-2C6 with symmetric branched side chain exhibited minimal absorption blueshift (20 nm) upon H-aggregation, enhanced NIR harvesting ability and a further ∼2-fold enhancement in ROS generation over the initial TNCF3-C6-C2 H-aggregates, thereby delivering potent tumor inhibition both in vitro and in vivo. Built upon the hierarchical programming of H-aggregates, this work establishes a supramolecular design paradigm toward modulating excitonic coupling and excited-state dynamics for high-performance photo-functional materials.
Original Research
OCT 14GuoAdvanced Optical Materials
Novel Carbonyl/Nitrogen Polycyclic Frameworks for Developing Multi‐Resonance Materials with Narrow‐Spectrum Emissions
Organic luminescent materials with multi‐resonance (MR) characteristics are emerging as promising candidates for achieving high‐definition organic light‐emitting diode (OLED) displays. Currently, the major MR compounds are built with boron/nitrogen (B/N) ‐embedded polycyclic aromatic frameworks but suffer from complicated synthesis with low yields and poor solubility. Herein, a facile method to create carbonyl‐nitrogen (C═O/N)‐based MR compounds is reported in this work. A series of novel C═O/N MR compounds containing electron‐neutral, electron‐withdrawing, and electron‐donating aromatics are synthesized and characterized. These compounds exhibit good thermal stability and exceptional high solubility. X‐ray crystallographic analysis and theoretical simulations reveal their bended structures with high rigidity and MR features. They show blue to sky‐blue emissions with a narrow full width at half maximum (FWHM) of ∼20 nm in toluene solutions. When integrated into sensitizer‐free OLEDs, they exhibit narrow emission profiles with FWHM of ∼30 nm and provide good maximum external quantum efficiencies of up to 14.3%. The results presented in this work enrich the library of C═O/N‐based polycyclic frameworks and establish a versatile design roadmap for high‐performance full‐color MR luminescent materials.