Triphenylamine Research Articles

Versatile aza‐BODIPY‐based low‐bandgap conjugated small molecule for light harvesting and near‐infrared photodetection

AbstractThe versatile nature of organic conjugated materials renders their flawless integration into a diverse family of optoelectronic devices with light‐harvesting, photodetection, or light‐emitting capabilities. Classes of materials that offer the possibilities of two or more distinct optoelectronic functions are particularly attractive as they enable smart applications while providing the benefits of the ease of fabrication using low‐cost processes. Here, we develop a novel, multi‐purpose conjugated small molecule by combining boron‐azadipyrromethene (aza‐BODIPY) as electron acceptor with triphenylamine (TPA) as end‐capping donor units. The implemented donor–acceptor–donor (D–A–D) configuration, in the form of TPA‐azaBODIPY‐TPA, preserves ideal charge transfer characteristics with appropriate excitation energy levels, with the additional ability to be used as either a charge transporting interlayer or light‐sensing semiconducting layer in optoelectronic devices. To demonstrate its versatility, we first show that TPA‐azaBODIPY‐TPA can act as an excellent hole transport layer in methylammonium lead triiodide (MAPbI3)‐based perovskite solar cells with measured power conversion efficiencies exceeding 17%, outperforming control solar cells with PEDOT:PSS by nearly 60%. Furthermore, the optical bandgap of 1.49 eV is shown to provide significant photodetection in the wavelength range of up to 800 nm where TPA‐azaBODIPY‐TPA functions as donor in near‐infrared organic photodetectors (OPDs) composed of fullerene derivatives. Overall, the established versatility of TPA‐azaBODIPY‐TPA, combined with its robust thermal stability as well as excellent solubility and processability, provides a new guide for developing highly efficient multi‐purpose electronic materials for the next‐generation of smart optoelectronic devices.image

Fluorinated/non-fluorinated triphenylamine axially substituted silicon phthalocyanine: Synthesis and photophysical properties

Three novel fluorinated/ non-fluorinated triphenylamine axially substituted silicon phthalocyanines with AIE character were synthesized. They shows typical emission for phthalocyanine moieties at 678–688 nm as well as an emission at 396 nm for TPA moieties. • Three fluorinated/ non-fluorinated triphenylamine substituted silicon phthalocyanines with AIE character were synthesized and characterized. • Three molecules showed an typical emission for phthalocyanine moieties at 678–688 nm as well as an emission at 396 nm for TPA moieties. • Silicon phthalocyanines with fluorinated and triphenylamine substitutions possessed the highest fluorescence intensity, fluorescence quantum yield and singlet oxygen yield. • Silicon (IV) phthalocyanine with only triphenylamine (TPA) substitutions exhibited obviously AIE character in THF/water mixtures. Three novel fluorinated/non-fluorinated triphenylamine axially substituted silicon phthalocyanines (TPA-FBPA-SiPc, TPA-BPA-SiPc and TPA-SiPc) with aggreagtion-induced emission (AIE) character were synthesized by using silicon phthalocyanine (SiPc) as a core, triphenylamine (TPA) moieties as terminal groups, and fluorinate or non-fluorinate-bisphenol A as bridge groups. Such designed molecules showed typical emissions for SiPc at 675–688 nm as well as emissions for TPA moieties at 396 nm. Their photophysical and photochemical properties are affected by both the fluorinate-bisphenol A substitutions and TPA substitutions. TPA-FBPA-SiPc with both fluorinate-bisphenol A and TPA substitutions possessed the highest fluorescence intensity, fluorescence quantum yield as well as singlet oxygen yield. Besides, TPA-SiPc with only TPA substitutions could not only avoid the aggregation-caused quenching of phthalocyanines but also exhibite obvious AIE character in THF/water mixtures due to the presence of TPA moieties. This work could provide some useful structure and photophysical properties relationship for design novel phthalocyanine for photodynamic therapy.

Noncovalent π–π dimerization based on acridine and acid-responsive luminescence switching

Noncovalent dimerization usually can induce distinct luminescence properties from those of monomer, but it is quite difficult to achieve in solid state, especially in films. Two acridine (AC) derivatives pTPA-AC and mTPA-AC were designed and synthesized with the chemical modification of AC by electron-donating triphenylamine (TPA) substituent at para- and meta-positions of TPA unit, respectively. Their crystals were resolved with antiparallel π–π dimeric AC stacking, demonstrating green fluorescence. Their doped films in a polymer matrix exhibited a distinct emission color change from blue to green with increasing doping percentage of pTPA-AC and mTPA-AC, indicating a facile noncovalent dimerization of AC in neat films. Upon protonation, a high-contrast acid-responsive luminescence switching was observed in these films with increasing doping ratio, which possesses not only a significant color change but also an on-off switch characteristic. This work provides a new molecular design strategy to develop the dimer materials of organic heterocycles, facilitating the antiparallel π–π dimer stacking in the film for both novel functions and practical applications.

Dual Emission, Aggregation, and Redox Properties of Boron Difluoride Hydrazones Functionalized with Triphenylamines

Abstractπ‐Conjugated molecular materials often exhibit interesting photoluminescence, redox, and optoelectronic properties that grant them utility as light‐harvesting materials in solar cells, as the emissive component of organic light‐emitting diodes, and as fluorescence sensors. Preparing dye conjugates by appending multiple dyes together to generate π‐conjugated molecules is a common strategy to enhance the properties of these materials as it often imparts traits that cannot be achieved by the building blocks independently. Herein, we report molecular materials that incorporate boron difluoride hydrazone (BODIHY) and triphenylamine (TPA) units that exhibit charge‐transfer character, dual‐emission, and aggregation‐induced emission. The title compounds have low‐energy absorption bands (λabs=455–493 nm) that are red‐shifted relative to BODIHYs with smaller π‐systems and exhibit dual‐emission in the solution, solid, and aggregate states. TPA–BODIHY (donor‐acceptor) conjugates show multiple reversible redox events and, in combination, the data presented herein indicate that there is electronic communication throughout the donor‐acceptor and acceptor‐donor‐acceptor π‐systems. These results are rationalized with the use of computational chemistry and solid‐state structural analysis. This study provides new opportunities for the design of molecular materials that are comprised of redox‐active photoluminescent dyes, including BODIHY, and their potential applications.

Origin of Red-Shifted Phosphorescence from Triphenylamines: Triplet Excimer or Impurity?

Triphenylamine (TPA) was reported to exhibit temperature-dependent dual phosphorescence, where the red-shifted band was assigned as the excimeric phosphorescence with an energy shift of >3000 cm-1 (J. Phys. Chem. 1991, 95, 7189). Here we show that purified TPA (purity: >99.97 %) shows a single phosphorescence band with a small energy shift of <200 cm-1 under the same experimental conditions. The new experimental results, along with theoretical calculations, suggest that the previously reported triplet excimer of TPA is probably not valid and is most likely due to an unidentified impurity. As-received TPA samples, however, do exhibit temperature-dependent dual phosphorescence bands, and the wavelength, relative intensity, and temperature dependence of the lower-energy phosphorescence band vary significantly depending on dopant structures. It was found that dopant phosphorescence could still become dominant even in dilute third-party solutions of the host at low temperature.

Flexible Organic Photovoltaics with Star‐Shaped Nonfullerene Acceptors End Capped with Indene Malononitrile and Barbiturate Derivatives

The design and synthesis of three star-shaped nonfullerene (NFA) acceptors, TPA-2T-INCN, TPA-2T-BAB, and TPA-T-INCN, based on a triphenylamine (TPA) core and linked through π-conjugated thiophene (T) spacers to different terminal units (3-oxo-2,3-dihydro-1H-inden-1-ylidene) malononitrile, INCN, and 1,3-dimethylbarbituric acid, BAB), are reported. These materials are blended with the widely used poly(3-hexylthiophene-2,5-diyl) (P3HT) donor polymer and tested in flexible organic photovoltaics (OPVs). The NFAs capped with the strong electron-withdrawing INCN unit perform best in OPVs. Both P3HT:TPA-T-INCN and P3HT:TPA-2T-INCN blends also show the highest photoluminescence quenching efficiency (95.8% and 92.6%, respectively). Surprisingly, when reducing the number of T spacers from 2 to 1, the solubility of the NFAs in o-dichlorobenzene increases, leading to easier processing during the OPV fabrication and better surface morphology. This explains the best performance of TPA-T-INCN-based blends in OPVs, with a champion power conversion efficiency of 1.13%.

Efficient red hybridized local and charge-transfer OLEDs by rational isomer engineering

Developing highly efficient red emitters with emission beyond 600 nm is full of challenges for organic light-emitting diodes (OLEDs). Herein, two novel red isomers of 11-DTPA-BBI and 3-DTPA-BBI manifesting hybridized local and charge-transfer (HLCT) state were designed and synthesized, based on triphenylamine (TPA) as donor and 7H-benzo[de]benzo[4,5]imidazo[2,1-a]isoquinolin-7-one (BBI) as acceptor. The charge-transfer (CT) component in HLCT state ensures their red emission and high excitons utilization, while the locally excited (LE) component guarantees the high fluorescence radiative rate. Further, the non-radiative transition is suppressed through regulating molecular vibration modes by isomer engineering, resulting in the high fluorescence quantum efficiency of 53% for 3-DTPA-BBI. Consequently, a maximum external quantum efficiency of 3.0% is achieved with emission peak at 604 nm in 3-DTPA-BBI based OLEDs. This contribution demonstrates a comprehensive structure-property relationship which may provide an effective guidance to design high performance red electroluminescent emitters.

Designing the optoelectronic properties of BODIPY and their photovoltaic applications for high performance of organic solar cells by using computational approach

A series of four novel pi-conjugated chromophores named BDP1-BDP4 have been designed in quest to enhance the PCE of organic photovoltaic cells. These chromophores were developed by using 4,4-difluroboradiaza-s-indacene (BODIPY) as a core, Triphenylamine (TPA) as donor and different end-capped acceptors i.e., 2-ethylidene malononitrile (BDP1), methyl-2-cyanobut-2-enoate (BDP2), 4-ethylidene-2-methyl-5-thiooxoisothiazolidin-3-one (BDP3), 2-(2-ethylidene-5,6-difluoro-3-oxo-2,3-dihydroinden-1-ylidene) malononitrile (BDP4). DFT and TD-DFT approach using B3LYP functional was employed to assess the photophysical, as well as opto-electronic properties of designed chromophores BDP1-BDP4. FMOs and Transition Density Matrix evaluations were executed to get insights about charge distribution, chemical reactivity, and stability of all molecules under investigation. Exciton binding energy and reorganization energy values have been computed to investigate exciton dissociation and charge carrier mobilities, respectively. All the newly developed molecules exhibit reduced band gap, red shift absorption bands, low exciton binding energy, small reorganization energy values and moderate Voc value in comparison to reference molecule which demonstrate that these newly developed molecules can be utilized as favorable photovoltaic materials. BDP4 considered to be promising acceptor molecule with highest λmax (883 nm), narrow band gap (1.22eV) and lowest λe value (0.01136). This theoretical and computational study revealed that the designed chromophores could be employed as efficient acceptors, in order to upsurge the quantum efficiency of organic photovoltaic devices.

Hydroxy-Tetraphenylimidazole Derivatives as Efficient Blue Emissive Materials for Electroluminescent Devices.

Herein, three hydroxy-tetraphenylimidazole (HPI)-based fluorophores (HPI-TPA, HPI-PCz, and HPI-CzP) are designed and synthesized by disubstituted HPI core with arylamine units of triphenylamine (TPA), phenyl carbazole (PCz), and carbazole phenyl (CzP) at 3,5-positions of the N-phenyl ring of HPI, respectively. Their photophysical properties are theoretically and experimentally examined. HPI-TPA shows a hybridized local and charge transfer (HLCT) excited state characteristic and emits deep blue color via an HLCT mechanism, while both HPI-PCz and HPI-CzP exhibit excited-state intramolecular proton transfer (ESIPT) property and display pure keto form emissions. They possess high thermal stability and are successfully fabricated as emitters in organic light-emitting diodes (OLEDs). All devices exhibit intense blue color emissions with low turn-on voltages (3.5-3.7 V). Particularly, HPI-TPA-based OLED emits light in the deep-blue region with a high maximum external quantum efficiency (EQEmax ) of 3.77% and a decent efficiency roll-off.

Highly Crystalline Graphene as the Atomic 2D Blanket of a Perovskite Absorber for Enhanced Photovoltaic Performance.

Perovskite solar cells (PSCs) have demonstrated enormous potential for next-generation low-cost photovoltaics. However, due to the intrinsically low bond energy of the perovskite lattice, the long-term stability is normally undermined by ion migration initiated by the electric field and atmospheric conditions. Therefore, ideal ion migration inhibition is important to achieve an enhanced stability of PSCs. Herein, we first introduce a chemical vapor deposition (CVD) fabricated highly crystalline graphene as an atomic 2D blanket directly for the perovskite absorber of PSCs. Iodine and lithium ion migration is effectively inhibited for perovskite solar cells under a continuous static electric field. The water and oxygen corrosion of the unencapsulated device has been dramatically mitigated with atomic graphene blanketing on the perovskite film. With triphenylamine (TPA) molecule modification, the photoconversion efficiencies (PCEs) of the blanketed devices reach 21.54%. The sample with blanket graphene maintains 85% of the initial efficiency, in comparison to 52% of the control sample under voltage bias. After 600 h of aging at 25 °C and 55 RH%, 86% in comparison to <30% of the PCE for the control device is obtained for the sample with a graphene blanket. Thus, we propose that crystalline graphene has an excellent and effective ion-blocking blanket potential for highly stable perovskite devices.

Deep‐Red Fluorescence from AIE‐Active Luminophore: High‐Brightness and Wide‐Range Piezochromism**

AbstractDriven by the rapidly increasing demand for intelligent materials, the sensitivity of organic materials to pressure has been intensively investigated in recent years. Many examples describe material responses to both mechanical grinding and hydrostatic pressure, but only few materials have been identified with clear colour difference as well as strong penetrability, especially under high pressure, limiting development of pressure sensors. In this work, an asymmetric luminophore, MTBA was developed by end‐capping a (Z)‐3‐(benzo[c][1,2,5]‐thiadiazol‐4‐yl)‐2‐phenylacrylonitrile (TPAN) core with propeller‐like triphenylamine (TPA) and rigid 12b‐methyl‐5,12b‐dihydroindeno[1,2,3‐kl]acridine (MeIAc) units, revealing aggregation‐induced emission (AIE) behaviour. In high‐pressure and grinding experiments, MTBA exhibits a dramatically large colour difference of up to 164 nm and 112 nm in deep‐red and near‐infrared regions, respectively, for piezochromic performance that is among the best reports for pure organic materials. The experimental and theoretical analyses indicated that the excellent piezochromic performance of MTBA is due to its highly twisty and rigid conformation, which weakens intermolecular π‐π interaction and obstructs emission quenching during compression.

Symmetrical end-capped molecular engineering of star-shaped triphenylamine-based derivatives having remarkable photovoltaic properties for efficient organic solar cells.

In the present research work, four novel triphenylamine (TPA)-based acceptor molecules have been architectured to step up the solar efficiency of organic solar cells. The four designed molecules abbreviated as T1-T4 have a common TPA donor core and different strong electron pulling peripheral acceptor groups connected through thiophene spacers. Computational simulations of T1-T4 were performed to compute and compare their optoelectronic properties with well-known reference molecule S(TPA-DPP) designated as R in the current project. For geometric optimizations of designed molecules, MPW1PW91 functional along with a basis set of 6-31G (d, p) was enforced. Assessment of the optoelectronic features of newly reported 3-D molecules (T1-T4) has been executed through density functional theory (DFT) and time-dependent density functional theory (TD-DFT) computations. Transition density matrix (TDM) and density of state (DOS) evaluations were performed for the investigation of exciton dynamics and electronic contribution between two states. All the derived molecules exhibited admirable photovoltaic features when compared to that of the reference molecule. Amidst all these newly modified molecules, T3 manifested itself as the finest candidate having the least energy band gap (1.84eV) and the highest λmax (865nm) in dichloromethane solvent. Also, T1 molecule has the lowest hole reorganization energy (0.0036eV) value. These designed candidates (T1-T4) confirm that peripheral acceptor tempering is an effectual approach for the attainment of the desirable optoelectronic properties.

An efficient solution-processable hybridized local and charge-transfer (HLCT)-based deep-red fluorescent emitter for simple structured non-doped OLED

The development of highly efficient deep-red fluorescent emitters is still a challenging task due to their intrinsic low bandgap characteristics resulting in low fluorescence emission in solid-state. Moreover, most of efficient deep-red organic light-emitting diodes (OLEDs) have complex device structures and are fabricated by high-cost vacuum deposition techniques. Herein, a novel solution-processable hybridized local and charge-transfer (HLCT) deep-red fluorescent molecule, TPA-NZF, is designed and synthesized as an emitter for low-cost and simple-structured OLEDs. TPA-NZF comprises a strong electron-deficient naphthothiadiazole (NZ) functionalized with triphenylamine (TPA) as a donor and dioctylfluorene as a solubilizing moiety. The photophysical results and theoretical calculations reveal a strong donor-acceptor feature and deep-red fluorescent emission with a solid-state photoluminescence quantum yield as high as 44%, decent hole-transporting mobility, good film morphology, and thermal and electrochemical stabilities. TPA-NZF is successfully fabricated as a solution-processed non-doped emitter in simple structured OLEDs. The device shows excellent electroluminescence (EL) performance (maximum external quantum efficiency (EQEmax) of 3.59%) and a deep-red emission with CIE coordinates of (0.66, 0.33).

Topological Design of Highly Anisotropic Aligned Hole Transporting Molecular Bottlebrushes for Solution-Processed OLEDs.

Polyvinyl polymers bearing pendant hole transport functionalities have been extensively explored for solution-processed hole transport layer (HTL) technologies, yet there are only rare examples of high anisotropic packing of the HT moieties of these polymers into substrate-parallel orientations within HTL films. For small molecules, substrate-parallel alignment of HT moieties is a well-established approach to improve overall device performance. To address the longstanding challenge of extension from vapor-deposited small molecules to solution-processable polymer systems, a fundamental chemistry tactic is reported here, involving the positioning of HT side chains within macromolecular frameworks by the construction of HT polymers having bottlebrush topologies. Applying state-of-the-art polymer synthetic techniques, various functional subunits, including triphenylamine (TPA) for hole transport and adhesion to the substrate, and perfluoro alkyl-substituted benzyloxy styrene for migration to the air interface, were organized with exquisite control over the composition and placement throughout the bottlebrush topology. Upon assembling the HT bottlebrush (HTB) polymers into monolayered HTL films on various substrates through spin-casting and thermal annealing, the backbones of HTBs were vertically aligned while the grafts with pendant TPAs were extended parallel to the substrate. The overall design realized high TPA π-stacking along the out-of-plane direction of the substrate in the HTLs, which doubled the efficiency of organic light-emitting diodes compared with linear poly(vinyl triphenylamine)s.

A NIR Aggregation-Induced Emission Fluoroamphiphile as Visually Trackable and Serum-Tolerant Nonviral Gene Carrier

Functional fluorescence (FL) nonviral gene vectors with high serum tolerance bear broad application prospects in gene delivery. Fluorination has been widely utilized as an effective strategy to enhance serum tolerance. Herein, we show the combination of fluorination and aggregation-induced emission (AIE) for the construction of a nonviral gene vector with low cytotoxicity, visual tracking ability, and high serum tolerance. Large π-conjugation triphenylamine (TPA) derivative with a characteristic D-π-A structure was modified with two polar [12]aneN3 heads and a long fluorocarbon tail, giving the vector molecule FluoTPA. FluoTPA features near-infrared (NIR) emission, large Stokes shift, and strong binding affinity toward nucleic acids. Liposomes consisting of FluoTPA and dioleoylphosphatidylethanolamine (DOPE) (FluoTPA/DOPE) can effectively deliver both plasmid DNAs (pDNAs) and siRNAs into cells. Impressively, FluoTPA/DOPE showed comparable transfection efficiency (TE) in the presence of serum content up to 30% with that in the serum-free condition and achieved 7.4 times higher TE than the commercial transfection agent lipofectamine 2000 at the same condition. Finally, spatiotemporal tracking of the delivery process in cells was demonstrated. The results in this work suggest that FluoTPA could be a reliable theranostic platform for the nonviral delivery of nucleic acid therapeutics in serum condition.

Facile Preparation of Cost‐Effective Triphenylamine‐Based Nanoporous Organic Polymers for CO2, I2, and Organic Solvents Capture

AbstractSeeking cost‐effective construction of nanoporous organic polymers for CO2 and I2 capture and organic solvents adsorption remains challenging. Two triphenylamine‐based nanoporous organic polymers, ANOP‐1 and ANOP‐2, have been prepared successfully by Friedel–Crafts (F–C) hydroxyalkylation from low‐cost triphenylamine (TPA) with commercial terephthalaldehyde and isophthalaldehyde, respectively. The effect of isomers of phenyl dialdehydes on the structure of porous architecture is investigated. The as‐prepared ANOPs exhibit a moderate uptake of CO2, I2, and organic solvents because of the electron‐rich TPA unit and nanometer‐scale pore size of &lt;2 nm. These findings demonstrate that F–C hydroxyalkylation is a cost‐effective strategy for producing large amounts of triphenylamine‐enriched, high specific BET surface area materials to develop commercial organic materials for industrial use.

Aggregation-induced emission enhancement (AIEE)-active donor-acceptor type fluorophores based on the 1,3-diaryl pyrazole unit: Conspicuous mechanochromic fluorescence and biosensing of iodide ions

Two type luminophore 1 and 2, with the same triphenylamine (TPA) and malonitrile-functionalized 1,3-diaryl pyrazole (MDP) units but with different π-conjugated spacer, were designed and synthesized. The crystals solid-state emission behavior and mechanical stimuli-responsive fluorescence characteristics of 1 and 2 were investigated. Interestingly, the fluorophores 1 and 2 exhibited yellow-green and yellow crystals solid-state fluorescent, respectively. Furthermore, 1 and 2 also exhibited obvious mechanochromic fluorescence behavior with repeated four cycles. Compared to 1 with an 80 nm red-shift, 2 is more sensitive to mechanical stimuli and exhibits a large red-shift emission of 85 nm. The powder XRD experiments demonstrated that the mechanochromic fluorescence behavior of 1 and 2 were related to the morphology transformation from crystalline state to amorphous state. In addition, based on the MDP moiety as I− receptor, 1 and 2 were qualified for sensing of I− with low limit of detection (89.0 nM, 149.9 nM). The biosensing of I− based on the better detection performance of the probe 1 was achieved in A549 cells and zebrafish. These results certify the great potential of MDP as a strong electron-deficient unit for designing D-A type mechanochromic fluorescence materials and biosensors for the detection of I− in organism.

Single Conjugated Polymer with Four Stepwise HOMO Levels for Effective Hole Injection Across Large Barrier 1.4 eV to Core–Shell Quantum Dot Layer for Electroluminescence in Inverted QLED

AbstractA novel graded‐HOMO‐level hole transport polymer (g‐HTP) is proposed for the first time with spiro‐polyfluorene (sPF) as the main chain and the three hole‐transporting moieties triphenyl amine (TPA), carbazole (Cz), and N,N′‐dicarbazolyl‐3,5‐benzene (mCP) as side chains for effective hole injection across the large barrier 1.4 eV into the green‐emission core–shell quantum dot (QD) CdSe/ZnS emission layer in inverted QD light‐emitting diode (i‐QLED): ITO/ZnO/QD/HTP/MoO3/Al, in which both oleophilic ligands (OA and TOP) in the QD are partially removed from QD surface by annealing at 270 °C for preventing dissolution by solvent in subsequent coating of hole transport material (HTM) solutions atop and also improving electron and hole mobilities, especially the former. The proposed g‐HTP with various m:n mole ratios of mCP to TPA/Cz moieties along with various reported HTMs (PVK, Poly‐TPD and TFB) are investigated. Among them, the proposed g‐HTP with the comonomer mole ratio 1:1 gives the best performance ηmax 36.1 cd A−1 and Bmax 208 600 cd m−2, which is the highest performance among the reported i‐QLEDs with single hole‐transport layer ever documented. In addition, its efficiency roll off is low from 35.8 cd A−1 at 10 000 cd m−2 to 31.1 cd A−1 at 100 000 cd m−2.

Triphenylamine-based conjugated microporous polymers as dye adsorbents and supercapacitors

Background: Conjugated microporous polymers CMPs have unique position among porous materials thus they are studied widely. Realistically, triphenylamine (TPA) derivatives generally possess high aromaticity, redox capabilities, high charge motilities, and outstanding electronic features, therefore designing CMPs based on TPA derivatives could result in fantastic properties.Methods: We performed one-pot coupling and polycondensation of a boronated triphenylamine derivative (TPA-3Bor) with bromobenzene (Bz-4Br) and bromopyrene (Py-4Br) derivatives to obtain two new TPA-based conjugated microporous polymers (TPA-Bz and TPA-Py CMPs, respectively). The successful synthesis of two TPA CMPs and their features were examined via Fourier transform infrared (FTIR) and 13C solid state NMR spectroscopies.Significant Findings: These two CMPs displayed attractive adsorptive properties toward the small dye molecule rhodamine B (RhB) from an aqueous solution. Outstanding adsorption performance, rapid kinetics, and good reusability suggest that our CMPs could function as effective adsorbents for RhB and, perhaps, other pollutants from wastewater. Moreover, our TPA-based CMPs displayed effective and stable performance when introduced as electrodes for supercapacitors, with capacitances as high as 78 F g–1 at a current density of 1 A g–1 as well as high stability. This study emphasizes the importance of conjugation and planarity in the future design of such materials.

New donor–π–acceptor AIEgens: Influence of π bridge on luminescence properties and electroluminescence application

Aggregation-induced emission (AIE) offers a solution to harvest strong solid-state fluorescence, which is crucial to achieving efficient organic light-emitting diodes (OLEDs). In this study, two novel AIE luminogens (AIEgens) were designed by integrating the advantages of triphenylamine (TPA) and phenanthroimidazole (PI), which exhibited excellent electron-donating ability of TPA and bipolar characteristics and suitable carrier transporting ability of PI. The two structural units were connected by a π bridge of tris/tetrastyrene group with a different number of benzene rings. Intra-/inter-molecular charge transfer can be obtained by adjusting the conjugation of the π bridge, and the AIE activity is also manipulated accordingly. The dilute solutions of TPE-TPAPPI present concentration- and polarity-dependent emission, demonstrating emission Adjustability by controlling the ratio of intramolecular and intermolecular charge transfer. It is found that intermolecular charge transfer dominates in film state. A non-doped OLED based on TPE-TPAPPI shows a maximum external quantum efficiency (EQE) of 4.01% with a low turn-on voltage of 3.2 V. The efficiency roll-off is only 4.75% even at a high brightness of 1000 cd m−2, demonstrating the superiority of our AIEgens in OLED application.