Latest ArticlesAn efficient approach to functionalized 4, 6-disubstituted-and 4, 6, 6-trisubstituted-1, 3-oxazinan-2-ones skeleton has been developed through the reaction of semicyclic N, O-acetals 4a and 4b with 1, 1- disubstituted ethylenes 5 or 8. As a result of such a [4 + 2] cycloaddition process, 4, 6, 6-trisubstituted- 1, 3-oxazinan-2-ones 6aa, 6af-6au, 7ba, 7bf-7bw and 6, 6-spiro containing 1, 3-oxazinan-2-ones 9ad, 9ae, 10ba-10bg were obtained in 36%-96% yields and with moderate to excellent diastereoselectivities. In addition, the synthesis of (±)-norallosedamine 12 could be conveniently achieved from the cycloadduct 7bf.
Functional dicyclophanes with various substituents (e.g., NO2, Br, OCH3 and OH) were synthesized via one-pot SN2 reaction. Dicyclophanes can form nanospheres via the head-to-tail self-assembly between the cavities and the TPE units to exhibit aggregation-induced emission (AIE) in aqueous solution. These AIE-active nanospheres with cationic feature exhibited selective recognition with fluorescence response for anionic ATP via electrostatic interactions and hydrophobic effects in water.
A photoinduced reaction of potassium alkyltrifluoroborates, sulfur dioxide, and para-quinone methides under visible light irradiation at room temperature is developed, giving rise to diarylmethyl alkylsulfones in moderate to good yields. This reaction works well under photocatalysis with a broad substrate scope by using DABCO·(SO2)2 as the source of sulfur dioxide. Mechanistic study shows that this transformation is initiated by alkyl radicals generated in situ from potassium alkyltrifluoroborates in the presence of photocatalyst. The subsequent insertion of sulfur dioxide and radical 1, 6-addition of para-quinone methides with alkylsulfonyl radical intermediates afford the corresponding diarylmethyl alkylsulfones.
The mixture of p-(methoxy)calix[n]arenes (n = 6, 7 or 8) was prepared in one step from p-methoxyphenol under basic conditions, and their fully methylated derivatives p-(dimethyloxy)calix[n]arenes (n = 6, 7 or 8) were also prepared and purified by column chromatography to indentify their structures. In this process, the single crystal of p-(dimethyloxy)calix[7]arene was obtained and its structure was confirmed. The proportion of p-(methoxy)calix[6]-, [7]- and [8]-arenes in the mixture obtained from the reaction was investigated under different reaction conditions, and p-(methoxy)calix[6]- and [8]-arenes could be separated from the mixture by solvent extraction. In addition, the host-guest interaction of p-(dimethyloxy)calix[6]arene with methyl-4, 4′-bipyridinium hexafluorophosphate in organic solvents was investigated.
A condition-controlled strategy for selectively synthesis of 2-acylbenzothiazoles and bibenzo[b][1, 4]thiazines from aryl methyl ketones and disulfanediyldianilines was realized using I2/DMSO or I2/MeCN systems, respectively. The desired products were synthesized in only 15 min with moderate to excellent yields (50%-90%) under microwave-assisted, metal-free conditions. The strategy provides a great advantage for selective synthetic applications in the efficient synthesis of benzothiazoles and bibenzothiazines heterocycle compounds.
Solid oxide fuel cells (SOFCs) can directly convert renewable biogas into electricity with high efficiency at high temperature, however the long-term stability of SOFCs is significantly affected by the carbon deposition on the anode during cell operation. Herein, we report a novel carbon removal approach by high temperature infrared light driven photocatalytic oxidation. Upon the comparison of electrochemical performance of Ni-YSZ anode and TiO2 modified Ni-YSZ anode in the state-of-the-art single cell (Ni-YSZ/YSZ/LSCM), the modified anodes exhibit markedly improved peak powder density with simulated biogas fuel (70% CH4+ 30% CO2) at 850 ℃ with less coking after 40 h operation. The high activity and carbon deposition resistance of the modified anode is possibly attributed to the in situ generated hydroxyl radical from the reduced TiOx powder under high temperature infrared light excitation, which is supported by detailed analysis of microstructural information of anodes and the powder-based thermo-photocatalytic experiments.
Although transition metal phospho-sulfides deliver outstanding electrochemical performance, complex preparation methods hindered their further development. Herein, we report a facile one-step electrodeposition approach to deposit interconnected nanowalls-like nickel cobalt phospho-sulfide (Ni-Co-P-S) nanosheets onto the surface of carbon cloth. The thin Ni-Co-P-S nanosheets with multi-components and synergetic effects delivered rich active sites, further enhancing reversible capacitance. Therefore, the as-prepared Ni-Co-P-S electrode materials exhibit excellent electrochemical performance in a three-electrode system, showcasing a high specific capacitance of 2744 F/g at 4 A/g. The full supercapacitors based on Ni-Co-P-S as positive electrode and active carbon as negative electrode showcase a high specific capacitance of 110.9 F/g at 1 A/g, impressive energy density of 39.4 Wh/kg at a power density of 797.5 W/kg in terms of excellent cycling stability (91.87% retention after 10, 000 cycles). This simple electrode position strategy for synthesizing Ni-Co-P-S can be extended to prepare electrode materials for various sustainable electrochemical energy storage/conversion technologies.
Material stability is always the key factor for applied materials especially the working environment that requires higher temperature sensitivity or temperature fluctuation range. In which, the stimulus-response perovskite materials are just sensitive to stability to ensure the accuracy and stability of the signals, in the applied devices of batteries and memory storage devices and so on. However, it is still a tremendous challenge to improve the stability of perovskite materials, and maintain reliability in the devices. Here, a novel ABX2X'1 (X-site doping in an ABX3) compound [CEMP]-[CdBr2(SCN)] (1, CEMP = 1-(2-chloro-ethyl)-1-methyl-piperidine) with remarkable high-temperature reversible dielectric switching behavior was proposed. The strategy of [SCN]− doping in perovskite for improving the stability was successfully achieved. Meanwhile, the steric hindrance is increased while the energy barrier is also increased by replacing hydrogen with flexible groups, which leads to a high-temperature reversible phase transition. The new finding provides a new direction to enrich new applications and design ideas of perovskite materials. Especially the X-site strategy of doping or substitution in the ABX3, it will promote ingenious and perfect experimental results in material synthesis and performance improvement by chemistry disciplines.
Hydrogen isotope separation is a challenging task due to their similar properties. Herein, based on the chemical affinity quantum sieve (CAQS) effect, the D2/H2 separation performance of M2(m-dobdc) (M = Co, Ni, Mg, Mn; m-dobdc4− = 4,6-dioxido-1,3-benzenedicarboxylate), a series of honeycomb-shaped MOFs with high stability and abundant open metal sites, are studied by gases sorption and breakthrough experiments, in which two critical factors, gas uptake and adsorption enthalpy, are taken into consideration. Among these MOFs, Co2(m-dobdc) exhibits the longest D2 retention time of 180 min/g (H2/D2/Ne: 1/1/98) at 77 K because of its second-highest adsorption enthalpy (10.7 kJ/mol for H2 and 11.8 kJ/mol for D2) and the best sorption capacity (5.22 mmol/g for H2 and 5.49 mmol/g for D2) under low pressure of 1 kPa and 77 K), which make it a promising material for industrial hydrogen isotope separation. Moreover, the results indicate that H2 and D2 capacities under low pressure (about 1 kPa) dominate the final D2/H2 separation property of MOFs.
In this work, two aza-BODIPY derivatives, 3,5-diphenyl-1,7-di(p-dodecyloxyphenyl)-aza-BODIPY (CJF) and 3,5-di(p-bromophenyl-1,7-di(p-dodecyloxyphenyl)-aza-BODIPY (2Br-CJF) acted as model molecules to form the self-assembly monolayers on the solid-liquid interface. With the utilizing of scanning tunnelling microscope (STM), we demonstrated that intermolecular Br…F—BF interactions existed in 2Br-CJF self-assembly structure and played an important role in strengthening the stability of 2Br-CJF self-assembly structure. This result is supported by density functional theory (DFT) calculation.
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62662699(Operation and Technical Support)
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
