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A general approach to constructing room temperature phosphorescence (RTP) materials involves the incorporation of a phosphorescent emitter into a rigid host or polymers with high glass transition temperature. However, these materials often suffer from poor processability and suboptimal mechanical properties, limiting their practical applications. In this work, we developed benzothiadiazole-based dialkene (BTD-HEA), a multifunctional phosphorescent emitter with a remarkable yield of intersystem crossing (Φ ISC , 99.83 %). Its high triplet exciton generation ability and dialkene structure enable BTD-HEA to act as a photoinitiator and crosslinker, efficiently initiating the polymerization of various monomers within 120 seconds. A range of flexible phosphorescence gels, including hydrogels, organogels, ionogels, and aerogels were fabricated, which exhibit outstanding stretchability and recoverability. Furthermore, the unique fluorescent-phosphorescent colorimetric properties of the gels provide a more sensitive method for the visual determination of the polymerization process. Notably, the phosphorescent emission intensity of the hydrogel can be increased by the formation of ice, allowing for the precise detection of hydrogel freezing. The versatility of this emitter paves the way for fabricating various flexible phosphorescence gels with diverse morphologies using microfluidics, film-shearing, roll coating process, and two/three-dimensional printing, showcasing its potential applications in the fields of bioimaging and bioengineering., (© 2024 Wiley‐VCH GmbH.)

Organic near-infrared room temperature phosphorescence (RTP) materials offer remarkable advantages in bioimaging due to their characteristic time scales and background noise elimination. However, developing near-infrared RTP materials for deep tissue imaging still faces challenges since the small band gap may increase the non-radiative decay, resulting in weak emission and short phosphorescence lifetime. In this study, fused-ring pyrrole-based structures were employed as the guest molecules for the construction of long wavelength emissive RTP materials. Compared to the decrease of the singlet energy level, the triplet energy level showed a more effectively decrease with the increase of the conjugation of the substituent groups. Moreover, the sufficient conjugation of fused ring structures in the guest molecule suppresses the non-radiative decay of triplet excitons. Therefore, a near-infrared RTP material (764 nm) was achieved for deep penetration bioimaging. Tumor cell membrane is used to coat RTP nanoparticles (NPs) to avoid decreasing the RTP performance compared to traditional coating by amphiphilic surfactants. RTP NPs with tumor-targeting properties show favorable phosphorescent properties, superior stability, and excellent biocompatibility. These NPs are applied for time-resolved luminescence imaging to eliminate background interference with excellent tissue penetration. This study provides a practical solution to prepare long-wavelength and long-lifetime organic RTP materials and their applications in bioimaging., (© 2023 Wiley-VCH GmbH.)

The development of flexible, room-temperature phosphorescence (RTP) materials remains challenging owing to the quenching of their unstable triplet excitons via molecular motion. Therefore, a polymer matrix with T g higher than room temperature is required to prevent polymer segment movement. In this study, a RTP material was developed by incorporating a 4-biphenylboronic acid (BPBA) phosphor into a poly(vinylidene fluoride) (PVDF) matrix (T g =-27.1 °C), which exhibits a remarkable UV-light-dependent oxygen consumption phosphorescence with a lifetime of 1275.7 ms. The adjustable RTP performance is influenced by the crystallinity and polymorph (α, β, and γ phases) fraction of PVDF, therefore, the low T g of the PVDF matrix enables the polymeric segmental motion upon microwave irradiation. Consequently, a reduction in the crystallinity and an increase in the α phase fraction in PVDF film induces RTP after 2.45 GHz microwave irradiation. These findings open up new avenues for constructing crystalline and phase-dependent RTP materials while demonstrating a promising approach toward microwave detection., (© 2023 Wiley-VCH GmbH.)

Photodynamic immunotherapy is a promising treatment strategy that destroys primary tumors and inhibits the metastasis and relapse of distant tumors. As reactive oxygen species are an intermediary for triggering immune responses, photosensitizers (PSs) that can actively target and efficiently trigger oxidative stress are urgently required. Herein, pyrrolo[3,2-b]pyrrole as an electronic donor is introduced in acceptor-donor-acceptor skeleton PSs (TP-IS1 and TP-IS2) with aggregation-induced emission properties and high absorptivity. Meanwhile, pyrrolo[3,2-b]pyrrole derivatives innovatively prove their ability of type I photoreaction, indicating their promising hypoxia-tolerant advantages. Moreover, M1 macrophages depicting an ultrafast delivery through the cell-to-cell tunneling nanotube pathway emerge to construct TP-IS1@M1 by coating the photosensitizer TP-IS1. Under low concentration of TP-IS1@M1, an effective immune response of TP-IS1@M1 is demonstrated by releasing damage-associated molecular patterns, maturating dendritic cells, and vanishing the distant tumor. These findings reveal insights into developing hypoxia-tolerant PSs and an efficient delivery method with unprecedented performance against tumor metastasis., (© 2022 Wiley-VCH GmbH.)

Monotonous luminescence has always been a major factor limiting the application of organic room-temperature phosphorescence (RTP) materials. Enhancing and regulating the intermolecular interactions between the host and guest is an effective strategy to achieve excellent phosphorescence performance. In this study, intermolecular halogen bonding (CN⋅⋅⋅Br) was introduced into the host-guest RTP system. The interaction promoted intersystem crossing and stabilized the triplet excitons, thus helping to achieve strong phosphorescence emission. In addition, the weak intermolecular interaction of halogen bonding is sensitive to external stimuli such as heat, mechanical force, and X-rays. Therefore, the triplet excitons were easily quenched and colorimetric multi-stimuli responsive behaviors were realized, which greatly enriched the luminescence functionality of the RTP materials. This method provides a new platform for the future design of responsive RTP materials based on weak intermolecular interactions between the host and guest molecules., (© 2022 Wiley-VCH GmbH.)

Multicomponent spiropolymerization (MCSP) provides an efficient synthetic tool for the construction of spiropolymers based on nonspiro monomers. In this study, a method of MCSP using diisocyanides 1, diethyl acetylenedicarboxylate 2, and halogenated quinones 3 is developed for the in situ construction of bis-spiropolymers with high molecular weights (M w up to 29 200) and good yields (up to 87.7%) under mild reaction conditions. The structure of the obtained bis-spiropolymers is confirmed by gel permeation chromatography, Fourier transform infrared spectroscopy, and nuclear magnetic resonance analysis. Halogenated bis-spiropolymers show good thermal stability, good solubility, and film-forming ability. The photosensitizer rhodamine B is used as a doping agent to induce the photodegradation of the polymer P1a3c into small-molecule segments, which results in the slow release of halogenated spiro-groups under irradiation with simulated sunlight. This finding reveals that P1a3c has the potential to be applied in pesticides. Therefore, this MCSP is a novel method for preparing halogen-containing bis-spiropolymers, which accelerates the development of multifunctional polymer materials., (© 2021 Wiley-VCH GmbH.)

Polymers containing iminofuran (PIFs) are rarely reported due to the lack of simple and effective synthesis methods. In this work, a novel multicomponent cyclopolymerization (MCCP) of diisocyanides, activated alkynes, and 1,4-dibromo-2,3-butanedione using catalyst-free one-pot reactions under mild conditions to prepare PIFs containing bromomethyl groups is reported. PIFs with good solubility and thermal stability are obtained with high M w s (up to 19 600) and good yields (up to 89.5%) under optimized polymerization conditions. The structure of the PIFs is characterized by nuclear magnetic resonance, Fourier transform infrared spectroscopy, and gel permeation chromatography. The photophysical properties indicate that polymers P1a2b3 and P1c2b3 have cluster-triggered emission characteristics. Thin films made from PIFs quickly degrade under UV irradiation. Moreover, the obtained polymers are decorated with bromomethyl and carboxylate groups in the side chain, which can be postfunctionalized to prepare multifunctional materials, such as star branched polymers and biomedical carrier materials. Thus, this work not only enriches the field of polymerization based on isocyanates and activated alkynes but also provides a facile strategy toward functional iminofuran polymers., (© 2020 Wiley-VCH GmbH.)

Dual/multi-component organic doped systems with room-temperature phosphorescence (RTP) properties have been developed. However, the unknown luminescence mechanism still greatly limits the development of the doped materials. Herein, a new doped system exhibiting phosphorescence/fluorescence dual emission (Φ phos =4-24 % and τ phos =101-343 ms) is successfully constructed through prediction and design. A series of isoquinoline derivatives with different alkoxy chains were selected as the guests. Benzophenone was chosen as the host owing to the characteristics of low melting point and good crystallinity. The alkoxy chain lengths of the guests are first reported to be used to control the fluorescence and phosphorescence intensities of the doped materials, which results in different prompt emission colors. Additionally, the doped ratio of the guest and host can also control the luminous intensities of the materials. In particular, the doped materials still exhibit phosphorescent properties even if the ratio of the guest/host is as low as 1:100 000., (© 2020 Wiley-VCH GmbH.)

Increasing the quantum yield of near-infrared (NIR) emissive dyes is critical for biological applications because these fluorescent dyes generally show decreased emission efficiency under aqueous conditions. In this work, we designed and synthesized several multiarylpyrrole (MAP) derivatives, in which a furanylidene (FE) group at the 3-position of the pyrrole forms donor-π-acceptor molecules, MAP-FE, with a NIR emissive wavelength and aggregation-enhanced emission (AEE) features. Different alkyl chains of MAP-FEs linked to phenyl groups at the 2,5-position of the pyrrole ring resulted in different emissive wavelengths and quantum yields in aggregated states, such as powders or single crystals. Powder XRD data and single crystal analysis elucidated that the different lengths of alkyl chains had a significant impact on the regularity of MAP-FEs when they were forced to aggregate or precipitate, which affected the intermolecular interaction and the restriction degree of the rotating parts, which are essential components. Therefore, an increasing number of NIR dyes could be developed by this design strategy to produce efficient NIR dyes with AEE. Moreover, this method can provide general guidance for other related fields, such as organic solar cells and organic light-emitting materials, because they are all applied in the aggregated state., (© 2020 Wiley-VCH GmbH.)

Organic materials with long-lived, color-tunable phosphorescence are potentially useful for optical recording, anti-counterfeiting, and bioimaging. Herein, we develop a series of novel host-guest organic phosphors allowing dynamic color tuning from the cyan (502 nm) to orange red (608 nm). Guest materials are employed to tune the phosphorescent color, while the host materials interact with the guest to activate the phosphorescence emission. These organic phosphors have an ultra-long lifetime of 0.7 s and a maximum phosphorescence efficiency of 18.2 %. Although color-tunable inks have already been developed using visible dyes, solution-processed security inks that are temperature dependent and display time-resolved printed images are unprecedented. This strategy can provide a crucial step towards the next-generation of security technologies for information handling., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Heteroatom-containing spiropolymers were constructed in a facile manner by a catalyst-free multicomponent spiropolymerization route. P1a2b as the most potent of these spiropolymers, demonstrates cluster-triggered emission resulting from strong interactions with the MDM2 protein. By preventing the anti-apoptotic p53/MDM2 interaction, P1a2b triggers apoptosis in cancerous cells, while demonstrating a good biocompatibility and non-toxicity in non-cancerous cells. The combined results from solution and cell-based cluster-triggered emission studies, docking, protein expression experiments and cytotoxicity data strongly support the MDM2-binding hypothesis and indicate a potential application as a fluorescent cancer marker as well as therapeutic for this spiropolymer., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Cryosurgery has attracted much attention for the treatment of tumors owing to its clear advantages. However, determining the volume of frozen tissues in real-time remains a challenge, which greatly lowers the therapeutic efficacy of cryosurgery and hinders its broad application for the treatment of cancers. Herein, we report a freezing-induced turn-on strategy for the selective real-time imaging of frozen cancer cells. As a type of aggregation-induced emission (AIE) fluorogen, TABD-Py molecules interact specifically with ice crystals and form aggregates at the ice/water interface. Consequently, bright fluorescent emission appears upon freezing. TABD-Py molecules are enriched mostly in the cancer cells and exhibit high biocompatibility as well as low cytotoxicity; therefore, a freezing-induced turn-on imaging modality for cryosurgery is developed, which will certainly maximize the therapeutic efficacy of cryosurgery in treating tumors., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Fast deposition of aligning ambipolar polymers for high-performance organic field-effect transistors (OFETs) and inverter circuits are highly desired for both scientific studies and industry applications. Here, large-area and ordered polymer films are prepared by a bar-coating method at a rate of 120 mm s -1 in air. Atomic force microscopy and grazing-incidence wide-angle X-ray scattering analysis indicate uniform edge-on poly(fluoroisoindigo-difluorobithiophene-fluoroisoindigo-bithiophene) (PFIBI-BT) in 11.7 ± 1 nm film (≈5 layers). The elongated, uniformly oriented grains can reduce the adverse effects of the grain boundaries and facilitate charge transport in polymers. Furthermore, OFETs based on parallel film show high hole/electron mobilities up to 5.5/4.5 cm 2 V -1 s -1 , which are approximately nine times of the devices prepared by spin-coating. The gain of the inverter is as high as 174, which is one of the highest values in polymer inventers currently. These results demonstrate that the excellent bipolar performance of few-layer PFIBI-BT can be ensured while achieving the compatibility of the experimental process with industrial preparation., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Organic electronics generally deals with bulk, statistically averaged electrical properties of organic materials. Single-molecule electronic devices can then be viewed as linkers to these bulk properties. However, controlling charge transport in single-molecule systems still remains a formidable task and has prevented proliferation of these systems from research laboratories to household electronics. This Concept article provides a general overview of the recent advances made by our group in the field. We will describe several concepts in designing molecular functions towards controlling charge transport through molecular systems. It should be noted, however, that this Concept article is by no means comprehensive and readers should look elsewhere for a more comprehensive picture of molecular electronics., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Organic functional materials, including conjugated molecules and fluorescent dyes, have been intensely developed in recent years because they can be applied in many fields, such as solar cells, biosensing and bioimaging, and medical adjuvant therapy. Organic functional materials with aggregation-induced emission or aggregation-enhanced emission (AIE/AEE) characteristics have increasingly attracted attention due to their high quantum efficiency in the aggregated or solid state. A large variety of AIE/AEE materials have been designed and applied during the exponential growth of research interest in the abovementioned fields. Multiphenyl-substituted 1,3-butadiene (MPB), as a core structure that includes tetraphenyl-1,3-butadiene, hexaphenyl-1,3-butadiene and their derivatives, show a typical AIE/AEE feature and can be potentially used in all the above-mentioned fields. This review summarizes the design principles, the corresponding syntheses, and the structure-property relationships of MPBs, as well as their excellent innovative functionalities and applications. This review will be useful for scientists conducting chemistry, materials, and biomedical research in AIE/AEE-related fields., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Development of facile and economic approaches for assembling organic semiconductors into more ordered structures toward high charge mobilities is highly demanding for the fabrication of organic circuits. Here a simple and facile approach is reported to prepare conjugated polymer thin films with improved crystallinities and charge mobilities by self-assembling semiconducting polymers on water. The formation of polymer thin films with more ordered structures is attributed to coffee ring effect induced by solvent-evaporation on water, and the hydrophobic nature of conjugated polymers that forces the polymer chains to pack densely and orderly on water surface. This approach is applicable to typical semiconducting polymers, and charge mobilities of their thin films are boosted remarkably. Finally, this new method can be utilized to easily fabricate the array of field-effect transistors with high charge mobilities in an economic way.

2,3,4,5-Tetraphenyl-1H-pyrrole (TePP) was synthesized by a simple one-step reaction. The compound showed a balanced emission in both the solution and solid state with the absolute quantum yield of Φ F/THF =65.6 % and Φ F/solid =74.3 %, respectively. Temperature and viscosity variation measurements demonstrated that the phenyl group at the 1-position (N-position) of the pyrrole core can act as a rotor in pyrrole-based molecules, which can consume the excited energy and reduce the molecular emission in solution. TePP without the phenyl group at the 1-position can effectively enhance the emission in solution. Single-crystal analysis showed that the phenyl groups at the 2,5-positions of pyrrole extend the molecular conjugation and lock the conformation. The phenyl groups at the 3,4-positions with a twisted conformation prevent their molecules from close packing and are helpful for aggregated emission. A delicate balance between the twisting conformation and rigid conjugation takes advantage of both ACQ and AIE luminogens. The strategy can tune the AIE, ACQ, or solution and solid dual-state emission properties of pyrrole-based molecules by simply altering the position of phenyl groups, which provides a great opportunity to explore the luminescent mechanism in greater detail and to facilitate practical applications., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

We describe the synthesis as well as the optical and charge-transport properties of a series of donor-acceptor (D-A) ladder-type heteroacenes. These molecules are stable, soluble, and contain up to 24 fused rings. Structural analyses indicated that the backbones of S 10r and Se 10r are bent in single crystals. The three 10-ring heteroacenes were functionalized with thiol anchoring groups and used for single-molecular conductance measurements. The highest conductance was observed for molecular wires containing a benzoselenadiazole (BSD) moiety, which exhibits the narrowest band gap. Multiple charge-transport pathways were observed in molecular wires containing either benzothiadiazole (BTD) or BSD. The conductance is a complex function of both energy gap and orbital alignment., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Eight donor-π-acceptor (D-π-A) compounds employing triphenylpyrrole isomers (TPP-1,2,5 and TPP-1,3,4) as donors, malononitrile (CN) and 1H-indene-1,3(2H)-dione (CO) as acceptors, pyridone (P) and benzopyran (B) as π-linking groups were synthesized. The compounds exhibited aggregation-induced emission and piezochromic properties. Compared with previously reported donors, triphenylpyrroles induced all the compounds to have more remarkable photophysical properties. The compounds containing TPP-1,2,5 and P moieties displayed stronger fluorescence intensities, shorter emission wavelengths, and more distinct piezochromic properties. However, the same phenomenon was observed in the TPP-1,3,4-containing system if B was as π-linker. Moreover, the CN acceptor endowed the compound to have a relatively strong fluorescent intensity, in which CO induced a relatively long emission wavelength. That is, the photophysical properties of D-π-A compounds can be controlled by adjusting the structure of donor, linker and acceptor., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Single-molecular electronics is a potential solution to nanoscale electronic devices. While simple functional single-molecule devices such as diodes, switches, and wires are well studied, complex single-molecular systems with multiple functional units are rarely investigated. Here, a single-molecule AND logic gate is constructed from a proton-switchable edge-on gated pyridinoparacyclophane unit with a light-switchable diarylethene unit. The AND gate can be controlled orthogonally by light and protonation and produce desired electrical output at room temperature. The AND gate shows high conductivity when treated with UV light and in the neutral state, and low conductivity when treated either with visible light or acid. A conductance difference of 7.3 is observed for the switching from the highest conducting state to second-highest conducting state and a conductance ratio of 94 is observed between the most and least conducting states. The orthogonality of the two stimuli is further demonstrated by UV-vis, NMR, and density function theory calculations. This is a demonstration of concept of constructing a complex single-molecule electronic device from two coupled functional units., (© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Due to their high electron affinities, chemical and thermal stabilities, π-conjugated molecules with imide/amide frameworks have received considerable attentions as promising candidates for high-performance optoelectronic materials, particularly for organic semiconductors with high carrier mobilities. The purpose of this Research News is to give an overview of recent advances in development of high performance imide/amide based organic semiconductors for field-effect transistors. It covers naphthalene diimide-, perylene diimide- and amide-based conjugated molecules and polymers for organic semiconductors., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Two conjugated molecules, TADPP3 and TADPP2-TT, are reported, in which three and two dithienyldiketopyrrolopyrrole (DPP) moieties, respectively, are substituted at the meta positions of benzene. Based on cyclic voltammetry and absorption data, TADPP3 and TADPP2-TT possess similar HOMO and LUMO energies of about -5.2 and -3.4 eV, respectively. Thin films of TADPP3 and TADPP2-TT exhibit p-type semiconducting behavior with hole mobilities of 2.36×10(-3) and 3.76×10(-4)  cm(2)  V(-1)  s(-1) after thermal annealing. Molecules TADPP3 and TADPP2-TT were utilized as p-type photovoltaic materials to fabricate organic solar cells after blending with phenyl C71 butyric acid methyl ester (PC71BM) and phenyl C61 butyric acid methyl ester (PC61BM). The relatively low JSC and fill factor values can be attributed to poor film morphologies based on AFM and XRD studies. A solar cell with a thin film of TADPP3 with PC71BM in a weight ratio of 1:2 exhibits a high open-circuit voltage (VOC) of 0.99 V and a power conversion efficiency (PCE) of 2.47 %. Interestingly, TADPP3 can also be employed as an n-type photovoltaic material. The blended thin film of TADPP3 with P3HT in a weight ratio of 1:2 gave a high VOC of 1.11 V and a PCE of 1.08 % after thermal annealing., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Two diketopyrrolopyrrole (DPP)-based donor-acceptor (D-A) conjugated molecules, DPP-F and DPP-2F, which contain E-(1,2-difluorovinyl) moieties, are reported. The LUMO energies of DPP-F and DPP-2F were estimated to be -3.49 and -3.70 eV, respectively, based on their redox potentials and absorption spectral data; these values were clearly lowered because of the incorporation of electron-withdrawing E-(1,2-difluorovinyl) moieties. Organic field-effect transistors (OFETs) with thin films of DPP-F and DPP-2F were successfully fabricated with conventional techniques. Based on the respective transfer and output characteristics measured in an inert atmosphere, thin films of DPP-2F display ambipolar semiconducting behavior with hole and electron mobilities reaching 0.42 and 0.80 cm(2) V(-1) s(-1), respectively. The as-prepared OFET of DPP-2F already shows high hole and electron mobilities that are not influenced remarkably by thermal annealing. For thin films of DPP-F, only p-type semiconducting behavior was observed in both an inert atmosphere and air, and the hole mobility increased to 0.1 cm(2) V(-1) s(-1) after thermal annealing. XRD and AFM studies were performed with thin films of DPP-F and DPP-2F after annealing at different temperatures., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The simple one-pot syntheses of sulfur-rich thiepin-fused heteroacences with an alkylidene-fluorene framework, THA1 and THA6 (thiepin-fused heteroacene 1 or 6, in which the thiepin is conjugated at both ortho positions with SCH3 or SC6 H13 , respectively), is reported. Based on electrochemical studies and theoretical calculations, their LUMO energies are relatively low (-3.26 eV), and their HOMO and HOMO-1 orbitals are nearly degenerate. The thiepin ring contributes mainly to HOMO-1 and LUMO orbitals, however, HOMO orbitals dominantly reside on thienoacence rings. Within the crystal of THA1, the molecules adopt a herringbone arrangement and multiple intermolecular interactions lead to the formation of a 2D network. Interestingly, THA6 shows totally different intermolecular arrangements. Organic field-effect transistor (OFET) devices show both compounds exhibiting p-type semiconducting behavior. Thin films or microcrystals of THA1 possess relatively high hole mobility. Moreover, the mobilities of the microcrystal of THA1 along three directions are in the same order, thus the hole-carrier transporting within the hexagonal-plane of microcrystal of THA1 exhibits less anisotropic behavior. In comparison, both thin films and microrods of THA6 show low hole mobilities. This agrees well with the intermolecular arrangements and interactions within crystal of THA6. Further theoretical calculations reveal that significant intermolecular electronic coupling among HOMO-1 orbitals and sulfur atoms play an important role in intermolecular electronic coupling for THA1., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)