Latest ArticlesThe design and synthesis of a phenoxazine-based metal-organic tetrahedron (Zn4L4) as biomimetic lectin for selectively recognition of glucosamine (GlcN) was reported. Different from the free phenoxazine-based ligand (L), Zn4L4 displayed the highest fluorescent intensity enhancement efficiency toward GlcN over other related natural mono- and disaccharides. Fluorescence titration demonstrated a 1:1 stoichiometric host-guest complex was formed with an association constant about 4.03×104 L/mol. 1H NMR spectroscopic studies confirmed this selectivity resulted from the multiple hydrogen bonding interactions formed between GlcN and Zn4L4. The present results suggested that rational arrangement of recognition sites in the confined space of metal-organic cage is crucial for the selectivity toward target guests.
Transition metal-catalyzed carbene transfer reaction is one of the most notable advances for C−C bond formation reactionsduring the past decade, which has been widely employed in the preparation of C3-substituted indoles. Here, we described an efficient example of catalyst- and metal-free aminoboration of alkynes and C−C bond formation with diazo compounds to produce C3-substituted indoles. Diverse alkynylanilines and diazo compounds can be utilized for this tandem transformation under mild reaction conditions, resulting in broad functional group compatibility. Additionally, this metal-free strategy can be extended to construct substituted benzofurans.
The effect of cucurbit[7]uril (CB[7]) on fluorescence properties and biocompatibility of the bis-viologen biphenyl molecule (BPV22+) was investigated by using 1H NMR spectroscopy, fluorescence emission titration, and in vitro cytotoxicity experiments. CB[7] can be combined with BPV22+ in a stoichiometric ratio of 1:1 and 2:1. After the formation of host-guest complex, the fluorescence emission intensity of BPV22+ increased significantly, and the emission spectrum blue shifted. Meanwhile, the host-guest complexes showed better biocompatibility than BPV22+ in cell cytotoxicity studies. Results of this paper lay a foundation for the development of host-guest type of fluorescent probes, biological imaging and so forth.
As a new type of two-dimensional material, MXene's unique layered structure, outstanding electrical conductivity, low density, tunable surface chemistry, and solution processability make it receive extensive attention in various fields, especially for the lightweight shielding materials since the report on electromagnetic interference (EMI) shielding of 2D Ti3C2Tx in 2016. In this review, the progress on the MXenes material including their synthetic strategies, properties and EMI application is highlighted. First, the recent advance on the different synthesis methods and properties of MXene is summarized. According to their intrinsic characteristics, the application of MXene in EMI fields is then discussed. Finally, the challenges and perspective on the future development of MXene in low-cost preparation and practical application are proposed.
A new family of isostructural 3d-4f polymetallic complexes, formulated as [Cu6Ln5(μ3−OH)9 (C4H8O2N)6(C5H4ON)6(H2O)9]·(ClO4)6·(H2O)22 (Ln = Pr, 1; Nd, 2; Sm, 3; Eu, 4; Gd, 5), was successfully isolated through the simple hydrolysis reaction of 2-aminoisobutyric acid, 2-hydroxypyridine, Cu(CH3COO)2·H2O, and Ln(ClO4)3·6H2O. Notably, the [Cu6Ln5] clusters with high molecular symmetry of D3h are rare examples of 2-aminoisobutyric acid-based 3d-4f clusters. The successful theoretical modeling of 5 yielded that the Gd-Gd exchange is of order 0.2 K, whereas the Gd-Cu exchange is an order of magnitude larger. Magnetization data collected for complex 5 yield a magnetic entropy change (−ΔSm) of 19.6 J kg−1 K−1 at 3 K and 7 T, which may be attributed to the weak magnetic interactions between the component metal ions.
The abuse of antibiotics will cause an increase of drug-resistant strains and environmental pollution, which in turn will affect human health. Therefore, it is important to develop effective detection techniques to determine the level of antibiotics contamination in various fields. Compared with traditional detection methods, electrochemical sensors have received extensive attention due to their advantages such as high sensitivity, low detection limit, and good selectivity. In this mini review, we summarized the latest developments and new trends in electrochemical sensors for antibiotics. Here, modification methods and materials of electrode are discussed. We also pay more attention to the practical applications of antibiotics electrochemical sensors in different fields. In addition, the existing problems and the future challenges ahead have been proposed. We hope that this review can provide new ideas for the development of electrochemical sensors for antibiotics in the future.
A novel Pd-Fe/α-Al2O3 catalyst was synthesized by incipient-wetness impregnation method with bayberry tannin as chelating promoter and commercial hollow column Raschig ring α-Al2O3 as support for the synthesis of diethyl oxalate from CO and ethyl nitrite. A variety of characterization techniques including N2 physical adsorption, optical microscopy, scanning electron microscopy and energy dispersive system (SEM-EDS), inductively coupled plasma optical emission spectroscopy (ICP-OES), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), were employed to explore the relationship between the physicochemical properties and activity of catalysts. It indicated that a large number of phenolic hydroxyl groups in bayberry tannin can efficiently anchor the active component Pd, reduce the particle size and make the active Pd as a multi-ring distribution on the commercial α-Al2O3 support, which were beneficial to improve the catalytic activity for the production of diethyl oxalate from CO and ethyl nitrite. 0.3 wt% Pd-Fe/α-Al2O3 showed excellent catalytic activity and selectivity in a continuous flow, fixed-bed reactor with the loading amount of 10 mL catalysts. Under the mild reaction conditions, the space-time yield of diethyl oxalate was 978 g L-1 h-1 and CO conversion was 44% with the selectivity to diethyl oxalate of 95.5%.
A simultaneous C2-H arylation and C8-H alkylation of naphthalene ring has been achieved by palladium-catalyzed cascade reaction of N-(2-halophenyl)-2-(naphthalen-1-yl)acrylamides with aryl iodides, which provides an efficient method for synthesizing various aryl-substituted spirocyclic oxindoles. The protocol enables three CC bonds formation via an intramolecular Heck reaction and sequentially regioselective CH bond activation.
The series of heterodinuclear metal oxide carbonyls in the form of TaNiO(CO) n- (n = 5–8) are generated in the pulsed-laser vaporization source and characterized by mass-selected photoelectron velocity-map spectroscopy. During the consecutive CO adsorption, the μ2-O-bent structure initially is the most favorable for TaNiO(CO)5-, and subsequently both μ2-O-bent and μ2-O-linear structures are degenerate for TaNiO(CO)6-, then the μ2-O-linear structure is most preferential for TaNiO(CO)7-, and finally the η2-CO2-tagged structure is the most energetically competitive one for TaNiO(CO)8-, i.e., the CO oxidation occurs at n = 8. In contrast to the literature reported CO oxidation on heteronuclear metal oxide complexes generally proceeding via Langmuir–Hinshelwood-like mechanism, complementary theoretical calculations suggest that both Langmuir–Hinshelwood-like and Eley–Rideal-like mechanisms prevail for the CO oxidation reaction on TaNiO(CO)8- complex. Our findings provide new insight into the composition-selective mechanism of CO oxidation on heteronuclear metal complexes, of which the composition be tailored to fulfill the desired chemical behaviors.
An unprecedented chiral secondary amine-catalyzed [3 + 3] annulation of isatin N,N'-cyclic azomethine imines with α,β-unsaturated aldehydes was developed. This strategy allowed the construction of structurally novel spiro N-heterocyclic oxindole derivatives in good yields (up to 91%) and good to excellent enantioselectivities (up to >99% ee), albeit with modest diastereoselectivities (up to 3.1:1 dr).
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62199257
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
