Electron-donating Ability Research Articles

Planar Chiral Charge-Transfer Cyclophanes: Convenient Synthesis, Circularly Polarized Light-Responsive Photothermal Conversion and Supramolecular Chiral Assembly.

We report herein a series of macrocycles in which the densely π-stacked charge-transfer (CT) donor/acceptor with naphthalenediimides (NDIs) or perylene diimide (PDI) as acceptor moiety pairing various donor moieties are locked by covalent bond. The X-ray crystallography of C8BDT-NDI reveals a short intramolecular π-stacking distance around 3.4 Å and the existence of intermolecular donor/acceptor π-stacking (3.7 Å). The intramolecular CT is highly dependent on the electron-donating ability of donor moiety and replacing carbazole (C8KZ) with benzo[1,2-b:4,5-b']dithiophene (C8BDT) or dihydroindolo[3,2-b]indole (C8DN) redshift CT absorption into NIR region. Notably, both C8BDT-NDI and C8DN-NDI demonstrate excellent photothermal performance, which is a result of the active non-radiative pathways. Interestingly, the different molecular symmetry between donor and acceptor moiety in cyclophanes endow C8BDT-NDI and C8DN-NDI with intrinsic planar chirality. The enantiomeric C8BDT-NDI shows chiral selectivity for incident light, i.e., when irradiated by left-circularly polarized light, (R)-C8BDT-NDI is more sensitive and a higher maximum stable temperature is achieved. While, enantiomeric C8DN-NDI pack with different orientations forming M- and P-handedness helix, respectively, demonstrating molecular planar chirality being transferred and amplified through molecular assembly. These results provide insight into the intramolecular charge transfer in enforced D/A π-stacks in which CT interactions and planar chirality would be engineered through structural control.

Preparation, Characterization, In Vitro Biological Evaluation, DFT Calculations, and Molecular Docking Investigations of 1H-Imidazole-2-Carboxylic acid and Histidine-Based Mixed-Ligand Complexes.

Mixed-ligand complexes incorporating 1H-Imidazole-2-Carboxylic acid (IMCA) and Histidine (LHIS) show promise for biomedical and biotechnological applications. This study synthesizes and characterizes FeIMCALHIS, CoIMCALHIS, and NiIMCALHIS coordination compounds using metal chloride salts (FeCl3.6H2O, CoCl2.6H2O, NiCl2.6H2O) in ethanolic solutions. The complexes are characterized by spectroscopic methods (IR, UV-vis, and mass spectra), elemental analysis, conductivity, magnetic, and thermal analysis. Molar conductivity indicates their non-electrolytic nature. UV-vis spectra reveal absorption bands with pathochromic shifts, and electronic spectra show characteristic metal-ligand transitions, indicating their structural configuration and coordination geometry. 3D geometry optimization shows six-coordination around Fe(III) and Co(II) in FeIMCALHIS and CoIMCALHIS, and four-coordination around Ni(II) in NiIMCALHIS. Analysis of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) suggests decreased electron donation ability upon coordination. Electronic structure parameters (HOMO, LUMO, ionization potential, energy gap, electron affinity, chemical potentials, and electronegativity) provide further insights into stability and reactivity. The metal complexes exhibit enhanced antimicrobial, antioxidant, and anti-inflammatory activity compared to individual ligands, with FeIMCALHIS showing notable antimicrobial activity. Molecular docking analysis reveals strong binding interactions with target proteins, highlighting their potential therapeutic applications.

Exploring the Vital Role of Vitamins in Disease Prevention and Health Maintenance

The human body relies on vitamins to carry out fundamental functions, yet it is unable to produce them on its own. Certain nutrients, like phytochemicals, are considered essential as the body cannot produce them in sufficient quantities. While ideally vitamins are obtained through a healthy diet, supplements are often necessary. Vitamins are crucial for growth, metabolism, and overall health, with vitamin D being the only one the body can produce. Vitamers, related molecules with similar vitamin activity, make up the bulk of vitamins. Vitamin C is a potent antioxidant drug used in dermatology to treat photoageing and hyperpigmentation. L-ascorbic acid is the active form, with limited oral absorption, making topical application more effective. Its electron-donating ability is crucial for various physiological processes, and its deficiency can lead to scurvy. Vitamin E (tocopherols and tocotrienols) has demonstrated significant biological effects on enhancing human health and play a promising role in food systems Supplementation of α-tocopherol up to 0.2% in oils provides higher oxidative stability, making vitamin E a valuable functional ingredient for food preservation and nutritional quality enhancement.This study investigates the roles of vitamins C and E in disease prevention and management, highlighting their antioxidant properties and physiological functions. Both vitamins are crucial for neutralizing free radicals, thereby reducing oxidative stress linked to various diseases, including cardiovascular conditions, cancer, and neurodegenerative disorders. Vitamin C supports immune function and collagen synthesis, while Vitamin E contributes to cellular integrity and skin health. The research underscores the synergistic effects of these vitamins, which enhance each other's antioxidant capabilities and may improve overall health outcomes. By addressing their roles in disease processes, the study emphasizes the importance of adequate vitamin intake for promoting health and preventing illness

Theoretical Study of Three Ratiometric 1,8-naphthalimide Fluorescent Probes for Hydrogen Sulfide Detection.

Three ratiometric 1,8-naphthalimide fluorescent probes for hydrogen sulfide detection have been studied theoretically by using density functional theory and time-dependent functional theory. From the detailed comparison of the optimized geometries, it is found that the change of substituents has a slight effect on the structure of 1,8-naphthalimide fluorophore, and the effect is mainly located in the part attached to the changed substituent. The change of the electron-withdrawing or electron-donating ability of the substituents on the 1,8-naphthalimide has an effect on the electronic spectra. Based on the analysis of frontier molecular orbital, the intramolecular charge transfer process was found for the three probes and their corresponding products. Finally, the analysis of the energy gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital was elaborated. This work provides a theoretical explanation of the experimental results and thus contributes to the development of novel fluorescent probes in the future.

Electrochromic conjugated polymers: The relationship of gradient band gap and electrochromic performance

In the pursuit of high-performance electrochromic materials, in this paper, six donor-acceptor type with different gradient band gaps electrochromic conjugated polymers, named PBTz-T, PBTz-TT, PBTz-DT, PTBTO8-T, PTBTO8-TT, and PTBTO8-DT, were synthesized via direct (hetero) arylation polymerization, employing two benzothiadiazole derivatives with varying electron-accepting capabilities and three thiophene derivatives with different electron-donating capacities. The structures, optical, electrochemical, and electrochromic properties of the six polymers were investigated. As the number of fused thiophene increases, enhancing the electron-donating ability, a growth trend of electrochemical stability is observed for all polymers. Meanwhile, enhance electron-accepting capabilities of acceptors (from benzotriazole to benzothiadiazole) significantly lower the electronic band gap and improve electrochemical stability. PBTz-DT boasts a bleaching time of 0.3 s, outperforming most reported electrochromic polymers. PBTz-T, at 530 nm, exhibits exceptionally high coloration efficiency, reaching 916 cm2 C⁻1, and demonstrates higher electron utilization and lower energy consumption, making it an excellent candidate for high-performance electrochromic devices. This work compared studies the relationship of gradient band gaps of electrochromic conjugated polymers and their electrochemical and electrochromic performance, offers new insights into enhancing the electrochemical stability and synthesizing high coloration efficiency electrochromic materials.

Leveraging graph neural networks to predict Hammett’s constants for benzoic acid derivatives

The Hammett constants, σm and σp, reflect the electron-withdrawing and electron-donating abilities of substituents on aromatic compounds, and have been successfully used in various structure-activity relationship studies. However, determining these constants experimentally is both resource-intensive and time-consuming approach. In this study, we explore the use of graph neural networks (GNNs) to predict Hammett constant parameters using graph-based features. This innovative approach aims to provide rapid and efficient predictions of σm and σp values, eliminating the need for extensive computational and experimental setups. By leveraging the power of GNNs, we hope to streamline the process of obtaining these critical parameters, thereby facilitating more efficient reaction design and enhancing the applicability of linear free energy relationship studies in chemical research.

Enhanced Treatment of Antimony Mine Wastewater by Sulfidated Micro Zerovalent Iron (S-mZVI).

Commercial micron zerovalent iron (mZVI) and sulfur were used to prepare sulfidated micro zerovalent iron (S-mZVI) through ball milling. The corrosion potentials of mZVI and S-mZVI were -0.01 and -0.37 V, respectively, indicating S-mZVI possessed a stronger electron-donating ability. The practical antimony mine wastewater (C0(Sb(V)) = 3.8296 mg/L, pH = 8.29) was treated. If meeting the national discharge standard of 5 μg/L, 2.0 g/L mZVI and 1.6 g/L S-mZVI were required within 120 min. Passing N2 or reducing wastewater pH enhanced the treatment of Sb(V) by S-mZVI, in which the wastewater acidification was more effective. Once the wastewater pH was adjusted to 3.00, only 0.7 g/L S-mZVI and 40 min long time were needed to achieve the emission below 5 μg/L. Even S-mZVI underwent four cycles, and the final concentration of Sb(V) was as low as 4.67 μg/L. As the pHzpc value was 4.09 and the corrosion potential was -0.56 V at pH 3.0, the electron-donating ability of S-mZVI as well as the electrostatic attraction between the surface of S-mZVI and Sb(V) increased. Sulfidation of mZVI and then application under the acid condition significantly improved the treatment efficiency of Sb(V).

Reversibly Compressible Silanated Cellulose Nanofibril Aerogel for Triboelectric Taekwondo Scoring Sensors.

The integration of bio-based materials into triboelectric nanogenerators (TENGs) for energy harvesting from human body motions has sparked considerable research attention. Here, a silanated cellulose nanofibril (SCNF) aerogel is reported for structurally reliable TENGs and reversely compressible Taekwondo scoring sensors under repeated impacts. The preparation of the aerogel involves silanizing cellulose nanofibers (CNFs) with vinyltrimethoxysilane (VTMS), following by freeze-drying and post-heating treatment. The SCNF aerogel with crosslinked physico-chemical bonding and highly porous network is found to exhibit superior mechanical strength and reversible compressibility as well as enhanced water repellency and electron-donating ability. The TENG having a tribo-positive SCNF layer exhibits exceptional triboelectric performances, generating a voltage of 270V, current of 11µA, and power density of 401.1mWm-2 under an applied force of 8N at a frequency of 5Hz. With its inherent merits in material composition, structural configuration, and device sensitivity, the SCNF TENG demonstrates the capability to seamlessly integrate into a Taekwondo protection gear, serving as an efficient self-powered sensor for monitoring hitting scores. This study highlights the significant potential of a facilely fabricated SCNF aerogel for the development of high-performance, bio-friendly, and cost-effective Bio-TENGs, enabling their application as self-powered wearable devices and sports engineering sensors.

Enhanced CO2 Electroreduction to ethylene on Cu nanocube coated with nitrogen-doped carbon shell in-situ electro-derived from metal-organic framework

Electrochemical CO2 reduction reaction (CO2RR) to ethylene is one of the most promising technologies to achieve efficient use of carbon resources and sustainable development, in which the development of an efficient and stable electrocatalyst is particularly important. In this work, we develop a catalyst in situ electro-derived from Cu-based MOF for CO2RR to ethylene. We prepared nano Cu-MOF by microwave synthesis and supported it on a Cu foil substrate as a working electrode (denoted as MOF/Cu foil). During in situ electrolysis, Cu-MOF was converted into a highly dispersed nitrogen-doped carbon-coated Cu nanocube (denoted as Cu-cube/CN), which inhibited particle agglomeration and enhanced active site exposure. At a potential of −1.15 V vs. RHE, the Faradaic efficiency (FE) of the Cu-cube/CN catalyst for ethylene is 49.6 %, significantly higher than that of the original Cu foil electrode and Cu-MOF supported on the gas diffusion layer (GDL) prepared working electrode (denoted as MOF/GDL). In situ attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) and density functional theory (DFT) calculations studies indicate that due to the electron-donating ability of the CN coating, the adsorption of *CO is enhanced, increasing the *CO coverage, lowering the reaction free energy of *CO dimerization, promoting C-C coupling and ethylene generation. This work provides new insights for the development of efficient and stable electrocatalysts for CO2RR-to-ethylene production.

Dual-donor D-A-D types electrochromic conjugated polymers employed quinoxaline as the acceptor: Synthesis, electrochemistry, and electrochromism

In this work, two donor-acceptor-donor (D-A-D) type electrochromic conjugated polymers were prepared upon electrochemical oxidation through their precursors employed dual-thiophene derivatives as the donor units and quinoxaline as the acceptor unit. The effects of different donor substituents on the polymers’ electrochemical and electrochromic properties were carefully examined. Owing to the introduction of stronger electron donor ability of 3,4-ethylenedioxythiophene (EDOT), P(Q-T-E) demonstrated good coplanarity and dense surface morphology, outstanding redox activity and stability (retained 97 % after 1000 cycles), low optical band gap (1.45 eV). P(Q-T-T) exhibited excellent electrochromic performance of above 30 % transmittance changes in both the NIR region and the visible region, as fast as 0.75 s response time, and high coloration efficiency value of 212.8 cm2 C−1. The Dual-donor strategy may provide a new research idea to achieve high-performance electrochromic D-A-D conjugated polymers.

A derivative of 3,3′,5,5′-tetramethylbenzidine for highly robust colorimetric sensing of nitrite in food samples

As an approved additive, nitrite has been widely used in food processing, but excessive intake can lead to serious health issues. Griess assay is currently the worldwide standard method for nitrite detection in food samples. However, the required highly acidic media (pH = 1) makes the use of corrosive strong acids unavoidable. 3,3′,5,5′-tetramethylbenzidine (TMB), the most widely used chromogenic substrate in ELISA, was proved to be nitrite-responsive in a buffered media (pH 2–3). However, the TMB-based nitrite assay suffered from signal instability that may be problematic for quantitative detection. Herein, we found that a TMB derivative, 3,3′-dimethoxy-5,5′-dimethylbenzidine (2OCH32CH3), allowed colorimetric sensing of nitrite with much improved stability over TMB. Detailed mechanistic analysis indicated both TMB and 2OCH32CH3 could be diazotized with nitrite. However, the product of 2OCH32CH3 is more stable due to the higher electron-donating ability of the methoxyl group that can stabilize the cationic diazotization product. Compared with the Griess assay (2 reagents, LOD 0.1 μM), the proposed 2OCH32CH3-based nitrite assay exhibited similar sensitivity (only one reagent, LOD 0.2 μM), but much lower acidity (pH = 3, buffered media). The practical application of the 2OCH32CH3-based assay was validated through detection of nitrite in various food samples. Moreover, to facilitate on-site monitoring, a self-assembled nitrite test kit was constructed and confirmed for nitrite testing in food samples.

Exploring the DNA-binding and anticancer potential of polypyridyl ruthenium(II) complexes

Organometallic medicines based on ruthenium (Ru) have attracted interest as chemotherapeutic and bioimaging agents due to their low toxicity and superior physical optical characteristics. However, there are still no ideal candidates in clinical trials due to the lack of understanding of the structure-activity relationships (SARs) of polypyrodyl Ru(II) complexes. Though increasing the electron-donating ability of the ligands has been proven to benefit bioactivity due to the fast hydroxylation rate between chlorine and DNA, the total electronic effects are much more important, especially for the binding modes between Ru(II)-polypyridyl complexes and DNA. By evaluating the electron-donating ability of the ligand complexes 1 - 4 through density functional theory (DFT) calculations, bioactivities tests, and docking studies, we investigated the relationship between the structures of Ru(II) complexes and cytotoxicity. Our findings showed that it was insufficient to merely consider the impact of electron-donating effects on biological activities in place of interaction modes. Furthermore, the cellular imaging study investigated the complex with phenyl substituents (1) and confirmed that the main target was DNA. Besides, the “off-on” emission phenomena of complex 1 indicated that there is also covalent interaction with DNA. These findings offer valuable insight into the development of SARs of polypyrodyl Ru(II) complexes.

Thiourea enhanced oxidase-like activity of CeO2/CuxO nanozyme for fluorescence/colorimetric detection of thiourea and glutathione

A novel fluorescence/colorimetric dual-mode sensor, based on enhancement of the oxidase-like activity of CeO2/CuxO nanozyme towards the oxidation of o-phenylenediamine (OPD) induced by thiourea (TU), has been proposed for TU detection. The catalytic activity enhancement on CeO2/CuxO can be attributed to the strong electron-donation ability of TU, which promoted hydroxyl radical generation and amplified OPD oxidization with enhanced dual-signal readout. By integrating a portable paper-chip and smartphone system, this CeO2/CuxO-OPD system achieved on-site visual colorimetric analysis of TU. The dual-mode sensor demonstrated high sensitivity and specificity in recognizing TU, with a detection limit (LOD) of 1.90 μM and a linear range (LR) 2.5–80 μM in fluorescent mode; as well as an LOD of 6.69 μM and an LR 10–250 μM in colorimetric mode. Furthermore, the CeO2/CuxO-TU-OPD system has been designed for dual-mode glutathione (GSH) detection with enhanced sensitivity, achieving an LOD of 0.19 μM and an LR 0.5–10 μM in fluorescent mode; as well as an LOD of 1.24 μM and an LR 1.25–25 μM in colorimetric mode. Additionally, GSH discrimination (fluorescent mode) was successfully achieved in different biological samples, showing good consistency with the standard method. The recoveries ranged from 96.8 % to 116.7 % in serum samples and from 97.3 % to 107.7 % in cell lysates, with RSDs less than 2 %. This work not only introduced a novel approach to enhance oxidase-like activity of nanozymes but also provided an efficient field-suitable tool for enhanced dual-mode response towards TU and GSH.

Precise intramolecular-charge-transfer property modulation of D-A-type fluorescent probes for bifunctional detection of phosgene and nerve agent

Chemical warfare agents such as phosgene and nerve agents pose severe threats to national defense and public safety, yet the development of bifunctional ratiometric fluorescent probes for them is still in its infancy. Aimed at this target, an intramolecular-charge-transfer (ICT) modulation strategy via incorporating donors with varied electron-donating ability, is put forward. Based on it, a series of donor(D)-acceptor(A)-type fluorescent probes are designed and synthesized. It is found that as the ICT strength of probes weakens, a ratiometric fluorescent probe with bi-analyte identification of phosgene and diethylchlorophosphate (DCP, the mimic of nerve agent sarin) is gained. Upon exposure to phosgene and DCP, 3-(benzo[d]thiazol-2-yl)-4′-(1,2,2-triphenylvinyl)-[1,1′-biphenyl]-4-amine (BTTPE), with the weakest ICT property, presents discriminative bathochromic shifts (Δλem = 58 nm for phosgene and Δλem = 152 nm for DCP) and favorable limits of detection (LODs in solution: 6.42 nM for phosgene; 6.80 µM for DCP). Besides, the prepared BTTPE-based paper test strips combined with a smartphone can detect phosgene vapor under the colorimetric-fluorescent dual-mode sensing and enable the visual recognition and quantitative detection of DCP vapor, with LODs in the vapor phase of 0.29 ppm for phosgene and 0.49 ppm for DCP. Hereby, this work not only provides the ICT modulation strategy for the first time to realize the ratiometric fluorescence detection of phosgene/DCP but also opens up a new avenue for tailoring multifunctional fluorescent probes.

A new perspective on contaminants as "activators": Aromatic amine groups promoted degradation of tetracycline by ferrate(VI)

Occasionally, our group found that the degradation of tetracycline by ferrate(VI) could be promoted by four co-exist contaminants, containing aromatic amines (ofloxacin, diatrizoic acid, sulfadiazine and alachlor). This study investigated the promotion of aromatic amine groups on tetracycline degradation by ferrate(VI) by using aniline as a model compound. The results implied that the presence of aniline increased the degradation rate of tetracycline by 2.76 times, and the enhancement was weakened gradually with the decrease of pH from 10 to 7.5. The generation of Fe(IV) and·OH by the reaction between ferrate(VI) and aniline was proposed to enhance the degradation of tetracycline, supported by quenching experiments, electron paramagnetic resonance (EPR) and theoretical calculations. A positive correlation was found between the rate constant of tetracycline degradation and the electron-donating ability of the substituted amines (quantified by the Hammett substituent constants). In addition, the degradation of tetracycline was remarkably inhibited by HA and some inorganic ions such as NO3-, SO42-, Cl-, Ca2+, and Mg2+, and the inhibition also happened in the Songhua River water and the secondary effluent. The present study provided an insight into the complex oxidation process for the degradation of micropollutants containing aromatic amine by ferrate in water treatment.

Introduction of methoxy and trifluoromethyl groups into zinc porphyrin sensitizers applications in self-assembled dye-sensitized solar cells

In this study, we have successfully constructed two novel self-assembled composites, the ZnPx-ZnPAc (x = 1,2), which based on zinc porphyrin derivatives, and applied them to the development of dye-sensitized solar cells. The upper dye of these self-assembly’s features zinc porphyrin (ZnPx) as the core unit, while two different electron donors, methoxy (P1) and trifluoromethyl (P2), are introduced to enhance their photovoltaic properties. Photoelectrochemical studies showed that the power conversion efficiency of ZnP1-ZnPAc was superior to that of ZnP2-ZnPAc because ZnP1-ZnPAc had larger Jsc and Voc, which could be attributed to the stronger electron-donating ability of methoxy than trifluoromethyl. To further validate the photoelectrochemical results, we also characterized the assembly mode by spectroscopy, theoretical calculations and electrochemical impedance spectroscopy. And the measurements were consistent with the conclusions.

Electrochemical membrane systems for remediating ammonium-containing wastewater via coupling capacitance adsorption and oxygen reduction

As the main nitrogen-containing pollutant of industrial and agricultural wastewater, ammonium (NH4+) is obtainable from the natural nitrogen cycle and industrial emission. Electrochemical recovering nitrogen (N) from nitrate-polluted wastewater to produce ammonia (NH3) is a promising route to mitigate pollution risks and create economic values. Since side reactions at the electrodes are inevitable, and the competition mechanism between electric double layer capacitance (EDLC) behavior and side reactions is still unclear. Herein, electrochemical selective NH4+ recovery from wastewater was achieved by coupling NH4+ adsorption and side oxygen reduction reaction (ORR) in a novel electrochemical membrane extraction system using Ti3C2TX-based gas-diffusion cathodes. Batch experiments showcase simultaneous NH4+ removal and recovery, with TiOX/TiC-C exhibiting the highest removal capability of 408 mgN g−1. In situ Raman spectroscopy revealed the critical role of the four-electron transfer ORR reaction in the conversion of NH4+ to NH3. Density functional theory (DFT) showed that excellent electron-donating ability for NH4+ of TiOX/TiC-C electrode (1.97 eV) facilitated NH4+ diffusion onto electrode interface. The study sheds light on the intricate interplay between NH4+ adsorption and ORR, highlighting the significance of tailored support and vacancy engineering in advancing wastewater treatment and resource recovery.

In situ anchoring of bimetal (Cu, Fe) sulfides featured by sulfur vacancy and phosphorus doping within porous carbon nanocubes derived from Prussian blue analogs to activate peroxymonosulfate for the efficient degradation of organic pollutants

In this work, Prussian blue analogues (CuFe-PBA) derived copper-iron sulfides/N-doped porous carbon composite (CuFe-NC-SP-x) was prepared as an effective peroxymonosulfate (PMS) activator to degrade sulfadiazine (SDZ). A strategy that kills two birds with one stone was proposed to construct CuFe-NC-SP-x, i.e., S-etched CuFe-PBA (CuFe-PBA-S) was annealed with NaH2PO2 in N2 atmosphere to simultaneously introduce sulfur vacancy (Sv) and phosphorus doping. 40 μM SDZ was completely removed by CuFe-NC-SP-2/PMS in 20 min (0.2 g/L catalyst and 0.5 mM PMS). The kobs value obtained by CuFe-NC-SP-2 (0.48 min−1) was nearly 33 and 17 times higher than that of CuFe-PBA (0.014 min−1) and CuFe-PBA-S (0.028 min−1), respectively. Quenching tests, electron paramagnetic resonance (EPR) analysis indicated that PMS activation in the system involved radical pathway (26.1 % OH and 22.7 % SO4–) and non-radical pathway (17.8 % 1O2 and 33.4 % electron transfer process). OH, SO4– and 1O2 were mainly produced by S enhanced metal sites for PMS activation. The synergistic effect of Sv and P doping enabled the powerful electron transfer mechanism. Electrochemical tests and DFT calculations demonstrated that Sv existing in CuFe-NC-SP-x improved the electron donor ability and increased the adsorption energy toward PMS, and phosphorus doping accelerated the electron transport from SDZ to PMS. This work not only provides a novel strategy to synthesize a high effective PMS activator by introducing Sv and phosphorous doing in one step, but also manages to comprehensively understand the electron transfer activation mechanisms of PMS facilitated by Sv and phosphorous doping.

Ultrafast response of diketo-pyrrolo-pyrrole dyes with large two-photon absorption enhancement as well as AIE property

To study the effect of terminal groups substituent on the two-photon absorption (TPA) properties of [Formula: see text]-[Formula: see text]-[Formula: see text]-[Formula: see text]-[Formula: see text] structural dyes with diketo-pyrrolo-pyrrole (DPP) as central electron acceptor group, linear/transient absorption spectroscopy, one/two-photon fluorescence spectra, open-aperture [Formula: see text]-scan, and excited states quantum chemical calculations have been performed to systematically study the intermediate product electron acceptor J0 as well as three [Formula: see text]-[Formula: see text]-[Formula: see text]-[Formula: see text]-[Formula: see text] structural dyes using benzene, triphenylamine and 2,3-methoxy-triphenylamine as terminal electron donors, named as J1, J2, and J3, respectively. The intermediate product electron acceptor itself exhibits a relatively large TPA response, which indicates the DPP group has a large conjugated system. J2, with strong electron-donating ability groups triphenylamine as terminal groups, shows a large TPA cross-section of 534[Formula: see text]GM, which is approximately 10 times larger than that of J1 with weak electron pushing/pulling abilities groups benzene as terminal groups (51[Formula: see text]GM). The result indicates that the electron-donating abilities of terminal groups do play a key role in TPA response. Furthermore, methoxy substituent on the terminal triphenylamine groups can further effectively increase the TPA response, J3exhibits a 15-fold enhancement compared with that of J1. Transient absorption spectra and quantum chemical calculation results are well accorded with the experimental results. Terminal substituents with strong electron donor groups are beneficial for the formation of intramolecular charge transfer (ICT) process. Besides, methoxy substituent in the terminal of triphenylamine groups can further enhance the degree of ICT and induce AIE characteristics in the molecule.

Synthesis and Aggregation-Induced Emission Properties of New Carbazole-Based Pyranones and their Ring-Transformed Derivatives

AbstractA new series of N-phenyl-carbazole (N-phCbz) appended pyranones were designed and synthesized using α-oxo-ketene-S,S-acetal under mild reaction conditions in good yields. The reactivity of donor-acceptor (D-A)-based 2H-pyranones was utilized to develop their ring-transformed benzene-cored N-phenyl-carbazole derivatives. All the synthesized carbazole-based pyranones showed aggregation-induced emission (AIE) characteristics in 80–99% water fraction (f w) in DMSO. Among all the synthesized compounds, 6-(4-(9H-carbazol-9-yl)phenyl)-4-(methylthio)-2-oxo-2H-pyran-3-carbonitrile exhibited excellent AIE behavior with ca. 70-fold increase in fluorescence in 80% fw at 550nm. Furthermore, this compound showed exceptionally high fluorescence in nonpolar solvent (THF) as compared to polar solvents such as DMSO (ca. 200-fold increase in fluorescence). The DFT, DSC, and TGA analyses of the synthesized D-π-A compounds suggested the strong electron-donor ability of N-phCbz, with good thermal stability in the range of 231–393 °C. These N-phenyl-carbazole-appended pyranones with interesting AIE properties have great potential as probes for bioimaging applications as well as for optoelectronic materials.