Cyclized oligomer of tetracyanoquinodimethane-tetrathiafulvalene (TCNQ-TTF): a versatile macrocyclic molecule by DFT calculations

Journal of Inclusion Phenomena and Macrocyclic Chemistry - The combination of the electron donor and acceptor into a donor–acceptor system can transform the intermolecular charge transfer...     

A novel approach to synthesize dichlorobenzonitriles by selective ammoxidation

Research on Chemical Intermediates - Dichlorobenzonitriles are important organic intermediates for the production of many fine chemicals and are produced most economically and environment-friendly...     

Competitive Photoisomerization and Energy Transfer Processes in Fluorescent Multichromophoric Systems

Multichromophoric systems showing both fluorescence and photoisomerization are fascinating, with complex interchromophoric interactions. The experimental and theoretical study of a series of compounds, bearing a variable number of 4-dicyanomethylene-2-tert-butyl-6-(p-(N-(2-azidoethyl)-N-methyl)aminostyryl)-4H-pyran (DCM) units are reported. The photophysical properties of multi-DCM derivatives, namely 2DCM and 3DCM , were compared to the single model azido-functionalized DCM , in the E and Z isomers. The (EE)- 2DCM and (EEE)- 3DCM were synthesized via the click reaction. Steady-state spectroscopy and photokinetics experiments under UV or visible irradiation indicated the presence of intramolecular energy transfer processes among the DCM units. Homo- and hetero-energy transfer processes between adjacent chromophores were confirmed by fluorescence anisotropy and decays. Molecular dynamics simulations for 2DCM were carried out and analyzed using a Markov state model, providing geometrical parameters (orientation and distance between chromophores) and energy transfer efficiency. This work contributes to a better understanding and rationalization of multiple energy transfer processes occuring within multichromophoric systems.     

Insight mechanism of nano iron difluoride cathode material for high-energy lithium-ion batteries: a review

Journal of Solid State Electrochemistry - Iron(II) fluoride (FeF2) is a promising candidate as the cathode material for lithium-ion batteries (LIBs) due to its quite high theoretical energy density...     

Insulating Polymers as Additives to Bulk-Heterojunction Organic Solar Cells: The Effect of Miscibility

Adding insulating polymers to conjugated polymers is an efficient strategy to tailor their mechanical properties for flexible organic electronics. In this work, we selected two insulating polymers as additives for high-performance photoactive layers and investigated the mechanical and photovoltaic properties in organic solar cells (OSCs). The insulating polymers were found to reduce the electron mobilities in the photoactive layers, and hence the power conversion efficiencies were significantly decreased. More importantly, we found that the insulating polymers exhibited negative effect on the mechanical properties of the photoactive layers, with reduced Young's modulus and low crack onset strains. Further studies revealed that the insulating polymers had poor miscibility with the photoactive layers, providing large domains and more cavities in blend thin films, which act as negative effect for the tensile test. The studies indicate that rational selection of insulating polymers, especially enhancing the non-covalent interaction with the photoactive layers, will be critically important for the stretchable OSCs.     

Solvent terminated natural deep eutectic solvent microextraction for concentration of curcuminoids in Curcumae Longae Rhizoma and turmeric tea

A novel solvent terminated microextraction method based on a natural deep eutectic solvent (L-menthol and lactic acid at a molar ratio of 1:2) coupled with high-performance liquid chromatography was proposed, which was utilized for the separation and enrichment of bisdemethoxycurcumin, demethoxycurcumin and curcumin in Curcumae Longae Rhizoma and turmeric tea. The effects of independent parameters on extraction efficiency were optimized by single-factor analysis. Subsequently, four predominated parameters affecting the extraction procedure, including extractant volume, salt concentration, demulsifier consumption, and demulsification time, were further evaluated by a central composite design. Under the optimized conditions, the linear ranges of calibration curves were 0.005–0.5 μg/mL for bisdemethoxycurcumin, 0.004–0.4 μg/mL for demethoxycurcumin, and 0.0045–0.45 μg/mL for curcumin, respectively. In addition, the developed method provided low detection limits (0.1–0.4 ng/mL) and high enrichment factors (279–350). Its intra-day and inter-day precision were carried out by relative standard deviation ranging from 2.2 to 9.2%. Finally, the applicability of this method was assessed by the analysis of Curcumae Longae Rhizoma and turmeric tea samples. The results showed that these samples were detected successfully and the spiked recoveries over the range of 85.3-108.9% with relative standard deviations of 1.6-8.9% were attained, indicating its high relative recoveries with good precision in real sample analysis.     

SO2 Resisting Pd-doped Pr1-xCexMnO3 Perovskites for Efficient Denitration at Low Temperature

H₂-SCR is served as the promising technology for the controlling of NO_x emission, and the Pd-based derivative catalyst exhibited high NO_x reduction performance. Effectively regulating the electronic configuration of the active component is favorable to the rational optimization of noble Pd. In this work, a series of Pr_1-xCe_xMn_1-yPd_yO₃@Ni were successfully synthesized and exhibited superior NO conversion efficiency at low temperatures. 92.7 % conversion efficiency was achieved at 200 °C over Pr_0.9Ce_0.1Mn_0.9Pd_0.1O₃@Ni in the presence of 4 % O₂ with a GHSV of 32000 h⁻¹. Meanwhile, the outstanding performance was obtained in the resistance to SO₂ (200 ppm) and H₂O (8 %). Deduced from the results of XRD, Raman, XPS, and H₂-TPR, the modification of d orbit states in palladium was confirmed originating from the incorporation in the B site of Pr_0.9Ce_0.1Mn_0.9Pd_0.1O₃. The existence of higher valence (Pd³⁺ and Pd⁴⁺) than the bivalence in Pr_0.9Ce_0.1Mn_0.9Pd_0.1O₃ catalyst was evidenced by XPS analysis. Our research provides a new sight into the H₂-SCR through the higher utilization of Pd.     

An insight into the electrocatalytic properties of porous La0.3Sr0.7Fe0.7Cr0.3O3−δ electrodes towards oxygen reduction reaction

Journal of Solid State Electrochemistry - The electrocatalytic properties of porous La0.3Sr0.7Fe0.7Cr0.3O3−δ electrodes towards oxygen reduction reaction were investigated as a function...     

Natural killer cell-derived extracellular vesicle significantly enhanced adoptive T cell therapy against solid tumors via versatilely immunomodulatory coordination

Science China Chemistry - Insufficient tumor tropism, MHC class I molecules (MHC-I) defects of tumor cells, and immunosuppressive tumor micro-environment (TME) seriously imperil the efficacy of...     

Optimization of detection device geometry for NIR spectroscopy using a three-layered model of stone fruit

The influences of detection device geometry and fiber optic parameters on near infrared spectroscopy measurements were assessed using stone fruit models based on Monte Carlo simulation. The stone fruit was modeled as concentric spherical layered tissues including the skin, the flesh and the core. The choices of the detection angle, the diameter of the detection fiber, the numerical aperture, and the height of the probe were discussed. Receiving diffuse reflectance signals at detection angles in the range of 35°–50° and normalizing the detection signals by the collection area and the solid acceptance angle prior to use are suggested. Fiber probes with diameters D = 0.06 cm or 0.1 cm, NA = 0.20 or 0.30, and height h ≤ 0.8 cm are preferred. The probe deflection angle should be limited to within ±5° to guarantee measurement accuracy.