ORCID Profile
0000-0002-5213-7063
Current Organisation
Hong Kong University of Science and Technology
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Wiley
Date: 05-10-2021
Abstract: Stimuli‐responsive crystals capable of energy conversion have emerged as promising materials for smart sensors, actuators, wearable devices, and robotics. Here, a novel ferrocene‐based organic molecule crystal (Fc‐Cz) that possesses anisotropic piezoelectric, optical, and mechanical properties is reported. It is demonstrated that the new crystal Fc‐Cz can be used as an ultrasensitive piezoelectric material in fabricating strain sensors. The flexible sensor made of crystal Fc‐Cz can detect small strains/deformations and motions with a fast response speed. Analysis based on density functional theory (DFT) indicates that an external pressure can affect the dipole moment by changing the molecular configuration of the asymmetric single crystal Fc‐Cz in the crystalline state, leading to a change of polarity, and thereby an enhanced dielectric constant. This work demonstrates a new artificial organic small molecule for high‐performance tactile sensors, indicating its great potential for developing low‐cost flexible wearable sensors.
Publisher: Wiley
Date: 09-05-2021
Abstract: Development of simple and efficient red emissive luminogens is desirable yet challenging for optoelectronic devices due to the limited molecular design and the difficulties of synthesis. Red emitting molecules possess large π‐conjugated systems, which permit quenching in the solid state due to π–π stacking and are detrimental to the performance of devices. Furthermore, traditional red emitters usually exhibit emission far from pure red in the standard red, green, and blue (sRGB) gamut. Herein, two red luminogens, DCMa and DCIs, with aggregation‐induced emission (AIE) characteristics based on simple donor–acceptor (D–A) structures are explored. They show high fluorescence quantum yields (QYs) of 13.2% and 7.8% in the film state. Efficient nondoped solution‐processed organic light emitting diodes (OLEDs) with a configuration of indium tin oxide (ITO) oly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) oly[(9,9‐dioctylfluorenyl‐2,7‐diyl)‐ co ‐(4,40‐( N ‐(4‐sec‐butylphenyl)diphenylamine)] (TFB)/DCMa or DCIs/(1,3,5‐tris(2‐ N ‐phenylbenzimidazolyl)benzene) (TPBi)/LiF/Al are fabricated, which emit red electroluminescence at 652 and 711 nm, respectively. Furthermore, they exhibit International Commission on Illumination (CIE) coordinates of (0.63, 0.36) and (0.64, 0.35), respectively, which are close to the value of the primary red color (0.63, 0.34) according to the digital television standard. These results of small molecules DCMa and DCIs suggest future methods for designing new red emitters for nondoped solution‐processed OLEDs.
Publisher: Springer Science and Business Media LLC
Date: 30-05-2023
DOI: 10.1038/S41467-023-38769-Y
Abstract: Exploring approaches to utilize abundant water to synthesize functional molecules and polymers with efficient clusteroluminescence properties is highly significant but has yet to be reported. Herein, a chemistry of water and alkyne is developed. The synthesized products are proven as nonaromatic clusteroluminogens that could emit visible light. Their emission colors and luminescent efficiency could be adjusted by manipulating through-space interaction using different starting materials. Besides, the free-standing polymeric films with much high photoluminescence quantum yields (up to 45.7%) are in situ generated via a water-involved interfacial polymerization. The interfacial polymerization-enhanced emission of the polymeric films is observed, where the emission red-shifts and efficiency increases when the polymerization time is prolonged. The synthesized polymeric film is also verified as a Janus film. It exhibits a vapor-triggered reversible mechanical response which could be applied as a smart actuator. Thus, this work develops a method to synthesize clusteroluminogens using water, builds a clear structure-property relationship of clusteroluminogens, and provides a strategy to in situ construct functional water-based polymeric films.
Publisher: American Chemical Society (ACS)
Date: 28-01-2021
Publisher: Wiley
Date: 07-12-2022
Abstract: We mapped the entire visible range of the electromagnetic spectrum and achieved white light emission (CIE: 0.31, 0.34) by combining the intrinsic ns‐fluorescence with ultralong ms‐phosphorescence from purely organic dual emitters. We realized small molecular materials showing high photoluminescence quantum yields (Φ L ) in the solid state at room temperature, achieved by active exploration of the regioisomeric substitution space. Chromophore stacking‐supported stabilization of triplet excitons with assistance from enhanced intersystem crossing channels in the crystalline state played the primary role for the ultra‐long phosphorescence. This strategy covers the entire visible spectrum, based on organic phosphorescent emitters with versatile regioisomeric substitution patterns, and provides a single molecular source of white light with long lifetime (up to 163.5 ms) for the phosphorescent component, and high overall photoluminescence quantum yields (up to Φ L =20 %).
Publisher: American Chemical Society (ACS)
Date: 20-01-2022
DOI: 10.1021/JACS.1C11480
Abstract: Long-persistent luminescence (LPL), also known as afterglow, is a phenomenon in which the material shows long-lasting luminescence after the cessation of the excitation source. The research of LPL continues to attract much interest due to its fundamental nature and its potential in the development of the next generation of functional materials. However, most of the current LPL materials are multicomponent inorganic systems obtained after harsh synthetic procedures and often use rare-earth metals. Recently, metal free organic long-persistent luminescence (OLPL) has gained much interest because it can bypass many of the disadvantages of inorganic systems. To date, the most successful method to generate OLPL systems is to access charge-separated states through binary donor-acceptor exciplex systems. However, it has been reported that the ratios of the binary systems affect OLPL properties, complicating the reproducibility and large-scale production of OLPL materials. Simpler OLPL systems can overcome these issues for the benefit of the development and adoption of OLPL systems. Here, we report on the rational design and synthesis of a single-component OLPL system with detectable afterglow for at least 12 min under ambient conditions. This work exemplifies an easy design principle for new OLPL materials. The investigation of the material provides valuable insights toward the generation of OLPL from a single-component system.
Publisher: Chinese Chemical Society
Date: 14-07-2022
Publisher: Wiley
Date: 27-07-2023
Abstract: Although photodynamic therapy (PDT) for thorough cancer treatment is hindered by the limited generation of reactive oxygen species (ROS) with short lifetime from photosensitizers, PDT‐induced antitumor immune response remedies the defects. Previous studies show that inducing immunogenic cell deaths is an attractive approach to activate antitumor immunity, which confers a robust adjuvanticity to dying cancer cells. In this work, hiphilic luminogens with aggregation‐induced emission characteristics (AIEgens) are rationally designed and synthesized. By modulating the hydrophobic π ‐bridge and zwitterionic functional groups, these AIEgens exhibit tunable organelle specificity to lysosome, endoplasmic reticulum, and plasma membrane and enhance ROS generation ability. Notably, the membrane‐targeting AIEgen namely TPS‐2 induces cell death and membrane rupture via PDT to facilitate the release of antigens and activation of immune cells. Furthermore, the size‐controlled TPS‐2 nanoaggregates are found to serve as an adjuvant, promoting antigen accumulation and delivery to sufficiently boost the in vivo antitumor immunity by only one dose injection in a prophylactic tumor vaccination model. This work thus provides new insights into optimizing AIE photosensitizers via a hydrophobicity–hydrophilicity balance strategy for evoking an antitumor immunity and directly suppressing the distanced tumor. A single small‐molecular system for PDT‐stimulated antitumor immunity is envisioned.
Publisher: Wiley
Date: 28-04-2021
Publisher: Springer Science and Business Media LLC
Date: 24-06-2023
DOI: 10.1038/S41467-023-39479-1
Abstract: Proximity effect, which refers to the low-lying ( n ,π*) and (π,π*) states with close energy levels, usually plays a negative role in the luminescent behaviors of heterocyclic luminogens. However, no systematic study attempts to reveal and manipulate proximity effect on luminescent properties. Here, we report a series of methylquinoxaline derivatives with different electron-donating groups, which show different photophysical properties and aggregation-induced emission behaviors. Experimental results and theoretical calculation reveal the gradually changed energy levels and different coupling effects of the closely related ( n ,π*) and (π,π*) states, which intrinsically regulate proximity effect and aggregation-induced emission behaviors of these luminogens. With the intrinsic nature of heterocycle-containing compounds, they are utilized for sensors and information encryption with dynamic responses to acid/base stimuli. This work reveals both positive and negative impacts of proximity effect in heterocyclic aggregation-induced emission systems and provides a perspective to develop functional and responsive luminogens with aggregation-induced emission properties.
Publisher: Research Square Platform LLC
Date: 17-01-2023
DOI: 10.21203/RS.3.RS-2465343/V1
Abstract: Water is always used by nature to construct complex species. Learning from nature, the exploration of artificial approaches to utilize abundant water to synthesize functional molecules and polymers with efficient clusteroluminescence properties (CLgens) is highly significant but has yet to be reported. Herein, a new chemistry of water and alkyne was developed. The synthesized products were proved as nonaromatic CLgens that could emit visible light. Their emission colors and luminescent efficiency could be adjusted by manipulating through-space interaction via using different water and alkyne. Besides, the free-standing polymeric films with much high photoluminescence quantum yields (up to 45.7%) were in situ generated via a new H 2 O-involved interfacial polymerization. The interfacial polymerization-induced emission of the polymeric films was observed, where the emission red-shifted and efficiency increased when the polymerization time was prolonged. The synthesized polymeric film was also verified as a "Janus film". It exhibits a vapor-triggered reversible mechanical response which could be applied as a smart actuator. Thus, this work develops a new method to synthesize CLgens using water, builds a clear structure-property relationship of CLgens, and provides a novel strategy to in situ construct functional H 2 O-based polymeric films.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1BM00044F
Abstract: With the morphological transformation of fluorescent self-assembled nanostructures, their functions can be varied simultaneously.
Publisher: American Chemical Society (ACS)
Date: 21-06-2022
Abstract: Hydrogen bonds not only play a crucial role in the life sciences but also endow molecules with fantastic physical and chemical properties, which help in the realization of their high-tech applications. This work presents an efficient strategy for achieving highly efficient solid-state dual-emission blue emitters with mechanical force-induced enhanced emission properties via intermolecular hydrogen bonds via novel pyrene-based intermediates, namely, 1,3,6,8-tetrabromo-2,7-dihydroxypyrene (
Publisher: Wiley
Date: 03-08-2022
Abstract: Dynamic patterns based on luminescent materials play an essential role in the digital age. However, it is still challenging to develop highly emissive photofluorochromic materials with dynamic behaviors to store information with multiple characteristics. Here, we report a series of dihydroazulene‐based compounds which show typical aggregation‐induced emission (AIE) effect. Moreover, the photo‐switching ability of the dihydroazulene units, undergoing light‐induced ring‐opening, enables photofluorochromic properties. The photofluorochromism also shows quantitively described responses to time and temperature via a reverse ring‐closing process. Ultimately, a rewritable 4D information system, embedded with a quick response code, dot matrix with microstructures, color matrix of fluorescence, and time/temperature‐dependent intensity change, is established with dynamic patterns. This work not only develops a dynamic AIE skeleton with photofluorochromic properties but also provides a new strategy for information encryption and cybernetics.
Publisher: Wiley
Date: 22-03-2023
Abstract: Functional materials with multi‐responsive properties and good controllability are highly desired for developing bioinspired and intelligent multifunctional systems. Although some chromic molecules have been developed, it is still challenging to realize in situ multicolor fluorescence changes based on a single luminogen. Herein, we reported an aggregation‐induced emission (AIE) luminogen called CPVCM, which can undergo a specific amination with primary amines to trigger luminescence change and photoarrangement under UV irradiation at the same active site. Detailed mechanistic insights were carried out to illustrate the reactivity and reaction pathways. Accordingly, multiple‐colored images, a quick response code with dynamic colors, and an all‐round information encryption system were demonstrated to show the properties of multiple controls and responses. It is believed that this work not only provides a strategy to develop multiresponsive luminogens but also develops an information encryption system based on luminescent materials.
Publisher: American Chemical Society (ACS)
Date: 11-06-2021
DOI: 10.1021/JACS.1C03882
Publisher: Wiley
Date: 16-11-2021
Abstract: Owing to their versatile functionality and tunable energy dissipation, aggregation‐induced emission luminogens (AIEgens) have emerged as a potential platform for multimodal theranostics. Nevertheless, the construction of AIE‐active phototheranostic agents in the second near‐infrared window (NIR‐II, 1000–1700 nm), which allows superior resolution and minimized photodamage, is still a formidable challenge. Herein, benzo[ c ]thiophene serves as an electron‐rich and bulky donor (D)/π‐bridge, which can enlarge the conjugation length and distort the backbone of an AIEgen. By precise D/π‐bridge engineering, highly stable NIR‐II AIEgen DPBTA‐DPTQ nanoparticles are obtained with acceptable NIR‐II fluorescence quantum yield and excellent photothermal conversion efficiency. In addition, the spatial conformation of DPBTA‐DPTQ is determined for the first time by X‐ray single crystal diffraction and theoretical simulations. DPBTA‐DPTQ NPs have good biocompatibility and show efficient photothermal therapeutic effects in in vitro tests. Furthermore, DPBTA‐DPTQ NPs were used in fluorescence‐photoacoustic‐photothermal trimodal imaging‐guided photothermal eradication of tumors in HepG2 and B16‐F10 tumor‐xenografted mice.
Publisher: American Chemical Society (ACS)
Date: 22-07-2021
DOI: 10.1021/JACS.1C05647
Abstract: Molecular motions are essential natures of matter and play important roles in their structures and properties. However, owing to the ersity and complexity of structures and behaviors, the study of motion-structure-property relationships remains a challenge, especially at all levels of structural hierarchy from molecules to macro-objects. Herein, luminogens showing aggregation-induced emission (AIE), namely, 9-(pyrimidin-2-yl)-carbazole (PyCz) and 9-(5-R-pyrimidin-2-yl)-carbazole [R = Cl (ClPyCz), Br (BrPyCz), and CN (CyPyCz)], were designed and synthesized, to decipher the dependence of materials' structures and properties on molecular motions at the molecule and aggregate levels. Experimental and theoretical analysis demonstrated that the active intramolecular motions in the excited state of all molecules at the single-molecule level endowed them with more twisted structural conformations and weak emission. However, owing to the restriction of intramolecular motions in the nano/macroaggregate state, all the molecules assumed less twisted conformations with bright emission. Unexpectedly, intermolecular motions could be activated in the macrocrystals of ClPyCz, BrPyCz, and CyPyCz through the introduction of external perturbations, and synergic strong and weak intermolecular interactions allowed their crystals to undergo reversible deformation, which effectively solved the problem of the brittleness of organic crystals, while endowing them with excellent elastic performance. Thus, the present study provided insights on the motion-structure-property relationship at each level of structural hierarchy and offered a paradigm to rationally design multifunctional AIE-based materials.
Publisher: Wiley
Date: 16-06-2023
Abstract: Clusteroluminescence (CL) and through‐space interactions (TSIs) of non‐conjugated molecules have drawn more attention due to their unique photophysical behaviors that are different from largely conjugated luminogens. However, achieving red and even near‐infrared (NIR) emission from such systems is still challenging due to the intrinsic drawbacks of non‐conjugated molecules and the lack of theories for structure–property relationships. In this work, six phenolic resins are designed and synthesized based on two molecule‐engineering strategies: increasing the number of TSIs units and introducing electron‐donating/‐withdrawing groups. All phenolic resins are verified as luminogens with CL property (CLgens), and the first ex le of CLgens with NIR emission (maximum emission wavelength ≥680 nm) and high absolute quantum yield (47 %) is reported. Experiments and theoretical analysis reveal that two TSIs types, through‐space locally excited state and through‐space charge transfer state, play essential roles in achieving CL from these non‐conjugated polymers, which could be manipulated via changing structural conformation and electron density or altering electron transition behaviors. This work not only provides an approach to manipulate TSIs and CL of non‐conjugated polymers but also endows commercially available phenolic resins with high practical value as luminescence materials.
Publisher: Wiley
Date: 04-12-2022
Abstract: Efficient theranostic systems can realize better outcomes in disease treatment because of precise diagnosis and the concomitant effective therapy. Aggregation‐induced emission luminogens (AIEgens) are a unique type of organic emitters with intriguing photophysical properties in the aggregate state. Among the AIEgens studied for biomedical applications, so far, metal‐based AIE systems have shown great potential in theranostics due to the enhanced multimodal bioimaging ability and therapeutic effect. This research field has been growing rapidly, and many rationally designed systems with promising activities to cancer and other diseases have been reported recently. In this review, we summarized the recent progress of metal‐based AIE materials in bioimaging and biological theranostics, and deciphered the pertinent design strategies. We hope that this review can offer new insights into the development of this growing field.
Publisher: American Chemical Society (ACS)
Date: 22-11-2022
Abstract: It remains a great challenge to design and synthesize organic luminescent molecules with strong emission in both dilute solution and aggregate state. Herein, an organic cage with dodecadansyl groups (D-RCC1) from an easy sulfonation reaction displays strong emissive behavior in dilute organic solution with a quantum yield of 42%. Moreover, D-RCC1 exhibits an ultrahigh quantum yield of 92% in the solid state, which is more than 3 times that of 27% for the model compound D-DEA. The results of the experiment and theoretical calculation show that the three-dimensional symmetrical skeleton of the organic cage anchored evenly by multiple dye molecules effectively satisfies both high local density and a symmetrical distribution of chromophores, which prevents the interaction of dye molecules and ensures that dye molecules have strong emission in both single-molecule and aggregate states.
Publisher: Wiley
Date: 07-12-2022
Abstract: We mapped the entire visible range of the electromagnetic spectrum and achieved white light emission (CIE: 0.31, 0.34) by combining the intrinsic ns‐fluorescence with ultralong ms‐phosphorescence from purely organic dual emitters. We realized small molecular materials showing high photoluminescence quantum yields (Φ L ) in the solid state at room temperature, achieved by active exploration of the regioisomeric substitution space. Chromophore stacking‐supported stabilization of triplet excitons with assistance from enhanced intersystem crossing channels in the crystalline state played the primary role for the ultra‐long phosphorescence. This strategy covers the entire visible spectrum, based on organic phosphorescent emitters with versatile regioisomeric substitution patterns, and provides a single molecular source of white light with long lifetime (up to 163.5 ms) for the phosphorescent component, and high overall photoluminescence quantum yields (up to Φ L =20 %).
Publisher: Wiley
Date: 16-02-2021
DOI: 10.1002/AGT2.36
Publisher: American Chemical Society (ACS)
Date: 21-06-2021
DOI: 10.1021/JACS.1C02594
Publisher: American Chemical Society (ACS)
Date: 25-05-2021
Publisher: American Chemical Society (ACS)
Date: 27-12-2022
DOI: 10.1021/JACS.2C10076
Publisher: American Chemical Society (ACS)
Date: 13-04-2021
DOI: 10.26434/CHEMRXIV.14400953.V1
Abstract: Apart from the traditional through-bond conjugation (TBC), through-space conjugation (TSC) is gradually proved as another important interaction in photophysical processes, especially for the recent observation of clusteroluminescence from nonconjugated molecules. Herein, simple and nonconjugated triphenylmethane (TPM) and its derivatives with electron-donating and electron-withdrawing groups were synthesized, and their photophysical properties were systematically studied. TPM was characterized with visible clusteroluminescence due to the intramolecular TSC. Experimental and theoretical results showed that the introduction of electron-donating groups into TPM could red-shift the wavelength and increase the efficiency of clusteroluminescence simultaneously, due to the increased electronic density and stabilization of TSC. However, TPM derivatives with electron-withdrawing groups showed inefficient or even quenched clusteroluminescence caused by the vigorous excited-state intramolecular motion and intermolecular photoinduced electron transfer process. This work provides a reliable strategy to manipulate TSC and clusteroluminescence.
Publisher: American Chemical Society (ACS)
Date: 05-09-2023
Publisher: American Chemical Society (ACS)
Date: 15-09-2023
DOI: 10.1021/JACS.3C08164
Publisher: American Chemical Society (ACS)
Date: 10-08-2022
DOI: 10.1021/JACS.2C07443
Abstract: Fluorescence imaging in the second near-infrared window (NIR-II, 1000-1700 nm) using small-molecule dyes has high potential for clinical use. However, many NIR-II dyes suffer from the emission quenching effect and extremely low quantum yields (QYs) in the practical usage forms. The AIE strategy has been successfully utilized to develop NIR-II dyes with donor-acceptor (D-A) structures with acceptable QYs in the aggregate state, but there is still large room for QY improvement. Here, we rationally designed a NIR-II emissive dye named TPE-BBT and its derivative (TPEO-BBT) by changing the electron-donating triphenylamine unit to tetraphenylethylene (TPE). Their nanoparticles exhibited ultrahigh relative QYs of 31.5% and 23.9% in water, respectively. By using an integrating sphere, the absolute QY of TPE-BBT nanoparticles was measured to be 1.8% in water. Its crystals showed an absolute QY of 10.4%, which is the highest value among organic small molecules reported so far. The optimized D-A interaction and the higher rigidity of TPE-BBT in the aggregate state are believed to be the two key factors for its ultrahigh QY. Finally, we utilized TPE-BBT for NIR-II photoluminescence (PL) and chemiluminescence (CL) bioimaging through successive CL resonance energy transfer and Förster resonance energy transfer processes. The ultrahigh QY of TPE-BBT realized an excellent PL imaging quality in mouse blood vessels and an excellent CL imaging quality in the local arthrosis inflammation in mice with a high signal-to-background ratio of 130. Thus, the design strategy presented here brings new possibilities for the development of bright NIR-II dyes and NIR-II bioimaging technologies.
Publisher: Wiley
Date: 03-08-2022
Abstract: Dynamic patterns based on luminescent materials play an essential role in the digital age. However, it is still challenging to develop highly emissive photofluorochromic materials with dynamic behaviors to store information with multiple characteristics. Here, we report a series of dihydroazulene‐based compounds which show typical aggregation‐induced emission (AIE) effect. Moreover, the photo‐switching ability of the dihydroazulene units, undergoing light‐induced ring‐opening, enables photofluorochromic properties. The photofluorochromism also shows quantitively described responses to time and temperature via a reverse ring‐closing process. Ultimately, a rewritable 4D information system, embedded with a quick response code, dot matrix with microstructures, color matrix of fluorescence, and time/temperature‐dependent intensity change, is established with dynamic patterns. This work not only develops a dynamic AIE skeleton with photofluorochromic properties but also provides a new strategy for information encryption and cybernetics.
Publisher: American Chemical Society (ACS)
Date: 09-10-2023
DOI: 10.1021/JACS.3C08627
Publisher: American Chemical Society (ACS)
Date: 08-08-2023
DOI: 10.1021/JACS.3C04027
Publisher: Wiley
Date: 11-02-2021
Publisher: Wiley
Date: 13-07-2022
Abstract: The proposed concept of aggregation‐induced emission (AIE) has offered an efficient strategy to design high‐performance luminescent materials. Herein, three blue emitters containing a pyrene core decorated with either triphenylamine or tetraphenylethylene units are presented. The designed compounds Py‐TPA and Py‐2TPE are AIE or active materials with blue emission from 464 to 478 nm in the solid state, whereas Py‐2TPA is not. Moreover, the enhanced thermal stability of compounds Py‐TPA and Py‐2TPE allows for their utilization as emitter layers for the fabrication of blue organic light‐emitting diode (OLED) devices. The devices exhibit excellent electroluminescence emission with maximum λ max em in the range 456–482 nm with a maximum external quantum efficiency of 7.27%, high exciton utilization efficiency (77.3%), and low turn‐on voltage (≤3.1 V), as well as low‐efficiency roll‐off. Theoretical calculations reveal that the high exciton utilization efficiency ( ƞ r ) originates from the triplet excitons at T 2 to the lowest single excited (S 1 ) state via a reverse intersystem crossing process following the principle of the “hot exciton” mechanism. This article not only provides powerful evidence revealing the advantages of pyrene‐based AIEgens for OLED applications, but also offers a new approach for designing pyrene‐based “hot exciton” materials for next‐generation OLEDs.
Publisher: Wiley
Date: 10-01-2022
Abstract: Phototheranostic agents have thrived as promising tools for cancer theranostics because of the integration of sensitive in situ fluorescence imaging and effective multi‐model synergistic therapy. However, how to manipulate the intangible photon energy transfer to balance the competitive radiative and nonradiative processes is still challenging. Although numerous phototheranostic molecules are reported, their complicated molecular design and tedious synthesis often stumble further their development. Herein, three simple molecules with electron donating−accepting structures are developed. The electron acceptor engineering on molecules by introducing acridinium unit gives rise to TPEDCAc with aggregation‐induced second near‐infrared emission (AIE NIR‐II), high reactive oxygen species generation capability, and excellent photothermal conversion efficiency (44.8%) due to the drastic intramolecular motion of large acridinium rotor and balanced AIE effect. Experimental analysis and calculation on the controlled molecules suggested that large torsional angle and the strong electron‐withdrawing ability of the acridinium unit are keys for NIR‐II emission and balanced photodynamic hotothermal conversion. Impressively, the positively charged TPEDCAc shows mitochondria‐targeting capability and high performance in in vivo multi‐modal cancer theranostics under NIR laser irradiation. Hence, this work not only provides a single NIR‐II AIE‐based multi‐modal cancer theranostic system but inspires new insights into future development of new theranostic platforms.
Publisher: Wiley
Date: 13-01-2023
Abstract: Photoswitches with multiple fluorescence states known as photofluorochromism upon photo‐induced isomerization show practical applications in information storage, anticounterfeiting, and sensors. However, it is still challenging to realize rapid isomerization, efficient fluorescence, and gradient signal output simultaneously. Herein, by incorporating luminogenic units with aggregation‐induced emission (AIE) features into photo‐responsive hydrazone, a series of novel photofluorochromic AIE compounds are developed. These newly designed compounds exhibit quantum yields of up to 38.4% and could undergo reversible and swift photo‐isomerization upon 450/365 nm irradiation. Accordingly, the fabricated photopatterns based on them are utilized as quantitatively described images for information storage, which show excellent rewritability and intensity‐variable fluorescence with a high resolution of 10 µm. This work provides a new strategy to develop intelligent photopattern systems with continuous gradient fluorescence for information storage and cybernetics.
Publisher: Wiley
Date: 31-10-2022
Abstract: Molecular aggregates with environmental responsive properties are desired for their wide practical applications such as bioprobes. Here, a series of smart near‐infrared (NIR) luminogens for hyperlipidemia (HLP) diagnosis is reported. The aggregates of these molecules exhibit a twisted intramolecular charge‐transfer effect in aqueous media, but aggregation‐induced emission in highly viscous media due to the restriction of the intramolecular motion. These aggregates, which can autonomously respond to different environments via switching the aggregation state without changing their chemical structures are described, as “smart aggregates”. Intriguingly, these luminogens demonstrate NIR‐II and NIR‐III luminescence with ultralarge Stokes shifts ( nm). Both in vitro detection and in vivo imaging of HLP can be realized in a mouse model. Linear relationships exist between the emission intensity and multiple pathological parameters in blood s les of HLP patients. Thus, the design of smart aggregate facilitates rapid and accurate detection of HLP and provides a promising attempt in aggregate science.
Publisher: Chinese Chemical Society
Date: 05-08-2022
Publisher: Wiley
Date: 24-01-2022
Abstract: Molecular motions are ubiquitous in nature and they immutably play intrinsic roles in all actions. However, exploring appropriate models to decipher molecular motions is an extremely important but very challenging task for researchers. Considering aggregation‐induced emission (AIE) luminogens possess their unique merits to visualize molecular motions, it is particularly fascinating to construct new AIE systems as models to study molecular motion. Herein, a novel quinolizine (QLZ) AIE system was constructed based on the restriction intramolecular vibration (RIV) mechanism. It was demonstrated that QLZ could act as an ideal model to visualize single‐molecule motion and macroscopic molecular motion via fluorescence change. Additionally, further elaborate tailoring of this impressive core achieved highly efficient reactive oxygen species production and realized fluorescence imaging‐guided photodynamic therapy applications, which confirms the great application potential of this new AIE‐active QLZ core. Therefore, this work not only provides an ideal model to visualize molecular motion but also opens a new way for the application of AIEgens.
Publisher: Springer Science and Business Media LLC
Date: 14-08-2023
DOI: 10.1038/S41929-023-01005-3
Abstract: Support-induced strain engineering is useful for modulating the properties of two-dimensional materials. However, controlling strain of planar molecules is technically challenging due to their sub-2 nm lateral size. Additionally, the effect of strain on molecular properties remains poorly understood. Here we show that carbon nanotubes (CNTs) are ideal substrates for inducing optimum properties through molecular curvature. In a tandem-flow electrolyser with monodispersed cobalt phthalocyanine (CoPc) on single-walled CNTs (CoPc/SWCNTs) for CO 2 reduction, we achieve a methanol partial current density of mA cm −2 with % selectivity, surpassing wide multiwalled CNTs at 16.6%. We report vibronic and X-ray spectroscopies to unravel the distinct local geometries and electronic structures induced by the strong molecule–support interactions. Grand canonical density functional theory confirms that curved CoPc/SWCNTs improve *CO binding to enable subsequent reduction, whereas wide multiwalled CNTs favour CO desorption. Our results show the important role of SWCNTs beyond catalyst dispersion and electron conduction.
Publisher: American Chemical Society (ACS)
Date: 16-11-2202
Abstract: Utilizing nonplanar conjugated molecules as building blocks facilitates the development of self-assembly but is fundamentally challenging. To study the self-assembly behavior, we herein demonstrate the self-assembly process of a nonplanar conjugated molecule with aggregation-induced emission (AIE) feature from an isolated molecule to an irregular cluster to a well-defined vesicle driven by hiphiles. The superhigh aggregation-sensitive emission affords more precise and detailed information about the self-assembly process than traditional dyes. Meanwhile, the arrangements of the AIE-active molecule change from disordered to well-organized forms by reducing the twisted configuration during the transformation process, and the strong hydrophobicity of hiphiles is crucial for such configuration and morphology transformations. Owing to the thermophilic bacteria-mimetic membranes, the obtained vesicles exhibit a property of superhigh thermal stability. They also display promising light-harvesting applications. This work not only deciphers the self-assembly of AIE molecules but also provides a strategy for nonplanar molecules to build well-organized self-assemblies.
Location: Hong Kong
No related grants have been discovered for Jianyu Zhang.