Latest ArticlesHerein, we report the NHC-Ru catalyst system that realizes the chemo-selective transformation of ketones with methanol. By simply changing the base, a broad range of structurally diverse ketones, could be selectively and efficiently converted to the corresponding β-methylated secondary alcohols or secondary alcohols. Remarkably, this catalytic system was very effective for the synthesis of bio-related molecules and deuterated alcohols, as well as the three-component coupling between methyl ketones, primary alcohols, and methanol. The reaction mechanism was further revealed by experiment and DFT mechanistic investigations.
Chemodynamic therapy (CDT) combined with dual phototherapy (photothermal therapy (PTT) and photodynamic therapy (PDT)) is an efficient way to synergistically improve anti-tumor efficacy. However, the combination of multiple modes often makes the composition of the system more complex, which is not conducive to clinical application. In this study, a dual phototherapy ligand carboxyl-modified Aza-BODIPY (BOD-COOH) and metal active center Cu2+ were used to construct multiple-modes metal-photosensitizer nanoparticles (BOD-Cu NPs) via one-step coordination self-assembly for combination therapy of CDT/PDT/PTT. In order to improve delivery efficiency, the targeted hydrophilic molecule pyridine-modified glucose derivative (G-Py) was synthesized and coated onto the BOD-Cu NPs to form a glycosylated nano metal-photosensitizer BOD-Cu@G by electrostatic interaction. The Cu2+ in BOD-Cu@G could not only be used as a coordination node for metal-driven self-assembly but also consume intracellular glutathione (GSH), and then catalyze Fenton-like reaction to generate hydroxyl radical (·OH) for CDT. In vitro and in vivo studies revealed that BOD-Cu@G could achieve excellent anti-tumor efficiency by CDT-enhanced dual phototherapy.
Herein, we report the migratory hydroarylation of unactivated alkenes with aryl iodides using native and weakly coordinating amide directors under mild conditions. Synergistic coordination of the monodentate directing group and the ligand enable the highly regioselective migratory hydroarylation via a chain walking process to form the thermodynamically stable five-membered nickelacyle intermediate. The protocol provides a variety of valuable α-aryl-substituted alkylamine products, and exhibited good functional group tolerance. The modification of bioactive compounds such as fenofibrate and indomethacin further highlights the synthetic value of this protocol.
The kinetic of low-temperature carrier and lattice of lead-halide perovskite is yet to be fully understood. In this work, we investigate the steady-state photoluminescences (PLs) of CsPbI3 at the environmental temperature (Te) ranging from 20 K to 300 K, and observed anomalous behaviors at cryogenic temperatures: The carrier temperature (Tc) of pure CsPbI3 exhibits a negative correlation with Te, accompanied by an expansion in Urbach tails of absorption spectra (Abs.) and excessive red-shifts at peak energy of PLs. These phenomena are also observed in those samples containing a certain amount of Cs4PbI6, but to a lesser extent and occurs at lower temperatures. It is attributed to the intensified hot phonon bottleneck effect (HPB) in CsPbI3 at cryogenic Te, which hinders the energy transfer from hot carriers, via longitudinal optics (LO) phonons to longitudinal acoustic (LA) phonons, to the ambient. For samples under continuous-wave laser excitation, in specific, the barrier induced by the enhanced HPB at low Te prevents the effective thermalization among carriers, LO and LA phonons, which, therefore, form thermally isolated ensembles with different temperatures. At cryogenic Te range, the elevated temperatures of carrier and LO phonon expand the high-energy side of PLs and the low-energy tail of Abs., respectively. For those samples in which the CsPbI3 is mixed with Cs4PbI6, the interfacial LO-LO interaction across them provides a bypass for heat dissipation, mitigating the heat accumulation in LO-phonons of CsPbI3. The results suggest that a strong HPB effect may break the thermal equilibrium among different branches of phonons in the lattice under certain extreme conditions.
The stable coordinated metallo-complexes based on 2,2′:6′,2″-terpyridine (tpy) and its derivatives have been widely researched for various wide-ranging applications in photoelectronics, catalysis, sensor, photoluminescence, and so on. However, the most reported studies ignored the comprehensive comparison between structures modified by different positions and photoluminescence. Herein, we design a series of metallo-complexes which were assembled with tpy substituted triphenylamine (TPA) at different positions and metal ions and explored their photophysical properties. In the solution state, MLE2 based on the 5,5″-positions modification showed the highest PLQYs and PL intensity. With the increase of solvent polarity, MLB2 exhibit the largest redshift. In the solid state, from MLA2 to MLE2, the emission colours are gradually red-shifted from yellow to red. The findings in this work may pave a new way to design functional metallo-complexes, not just for PL properties.
COVID-19 is a major event with worldwide influences. Since the beginning of the epidemic, pharmaceutical chemists have paid attention to the therapeutic effect of a variety of small molecule medicines on COVID-19 infection. A series of organic molecules are designed and found to be effective in the treatment of COVID-19 infection. In fact, no matter how effective they are, with the development of the COVID-19 epidemic, various small molecule medicines are gradually recognized by people. This is equivalent to a good science popularization of pharmaceutical chemistry. This review aims to introduce the molecules for COVID-19 treatment on the basis of their chemical structures, synthetic methods as well as their effects.
Effective adjustment and control of the oxidation state of plutonium (Pu) and neptunium (Np) is an indispensable component of Np/Pu separation in spent nuclear fuel reprocessing. Some hydrazine derivatives including methylhydrazine (CH3N2H3) effectively achieves the reduction of Np(Ⅵ) to Np(Ⅴ) without reducing Pu(Ⅳ). Herein, we explored the reduction mechanisms of Pu(Ⅳ) and Np(Ⅵ) by CH3N2H3 in HNO3 solution using scalar-relativistic density functional theory. We elucidated the difference in the reduction mechanism between Np(Ⅵ) and Pu(Ⅳ) ions by CH3N2H3. The energy barrier for the reduction of [NpⅥO2(H2O)5]2+ and [NpⅥO2(NO3)(H2O)3]+ by CH3N2H3 is largely different due to the coordination of nitrate ion. Moreover, the energy barrier of the reduction of [NpⅥO2(H2O)5]2+ is apparently lower than that of [PuⅣ(NO3)2(H2O)7]2+, which is in line with the experimental observations. The results of Mayer bond order and localized molecular orbitals clarify the structural evolution of the reaction pathways. Analysis of the spin density demonstrates that the first Np(Ⅵ) and Pu(Ⅳ) reduction belongs to the outer-sphere electron transfer and the second Np(Ⅵ) and Pu(Ⅳ) reduction is the hydrogen transfer. This study explains theoretically why CH3N2H3 reduces Np(Ⅵ) but not Pu(Ⅳ), and helps to design promising reductants for the Np/Pu separation in spent nuclear fuel reprocessing.
Herein, we report the first visible-light photoredox-catalyzed carboxylation of aryl epoxides with CO2 to synthesize hydroxy acid derivatives. A variety of valuable β-, γ-, δ-, ε-hydroxy acid derivatives are obtained in moderate to high yields under mild conditions. This protocol shows noteworthy functional-group compatibility, high chemo- and regioselectivities under transition-metal-free conditions with an inexpensive organo-dye as photosensitizer. Mechanistic studies indicate that the benzylic carbanion is generated as an intermediate via the sequential single electron transfer (SSET) process.
Herein, the degradation of florfenicol (FLO) over zero-valent iron (ZVI) enhanced by SiC was systematically investigated. It was found that 5 g/L of ZVI/SiC (1:3) at pH 3.0 could completely degrade 20 mg/L of FLO within 1 h, with a Kobs value of 0.0873 min−1, 12.5 times greater than that of pure ZVI (0.0069 min−1). Vibrating sample magnetometer (VSM) characterizations revealed that the use of SiC supporter reduces the magnetic intensity of ZVI, which mitigates iron particle agglomeration, increases Brunauer-Emmett-Teller (BET) surface area, and enhances FLO degradation efficiency. Furthermore, ZVI/SiC exhibits a much lower hydrogen evolution potential (HEP) and significantly higher corrosion currents compared to pure ZVI. FLO was proposed to undergo degradation via reductive dechlorination, involving a hydrogenolysis mechanism that entails the cleavage of the σ bond. This study provides new insights into the reduction hydrogenation mechanism of ZVI.
Utilizing CO2 for the production of bulky and valuable chemicals presents an attractive solution to address environmental and fossil energy crises. Among the various approaches, direct carboxylation of alcohols with CO2 stands out as an eco-friendly process capable of efficiently producing carboxylic acids in a sustainable manner. However, the high dissociation energy of the C-O bond poses a significant challenge in this process. Over the past few decades, several strategies have been developed to activate alcohols and establish efficient catalytic systems for carboxylation with CO2. Nevertheless, the sporadic nature of reported approaches makes it difficult to determine the most effective one. This perspective aims to provide an overview of the current state-of-the-art catalytic protocols for carboxylating alcohols with CO2, encompassing esterification, halogenation, and photocatalysis, while considering their respective advantages and limitations. We aim to discern the most promising avenues for future development in this field. The insights presented in this perspective will contribute to the advancement of efficient and sustainable carboxylation methods using CO2, leading to the production of valuable chemicals in future.
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
