Latest ArticlesHerein, an intense electrochemiluminescence (ECL) was achieved based on Pt hollow nanospheres/rubrene nanoleaves (Pt HNSs/Rub NLs) without the addition of any coreactant, which was employed for ultrasensitive detection of carcinoembryonic antigen (CEA) coupled with an M-shaped DNA walker (M-DNA walker) as signal switch. Specifically, in comparison with platinum nanoparticles (Pt NPs), Pt HNSs revealed excellent catalytic performance and pore confinement-enhanced ECL, which could significantly amplify ECL intensity of Rub NLs/dissolved O2 (DO) binary system. Then, the tracks and M-DNA walker were confined on the Pt HNSs simultaneously to promote the reaction efficiency, whose M-structure boosted the interaction sites between walking strands and tracks and reduced the rigidity of their recognition. Once the CEA approached the sensing interface, the M-DNA walker was activated based on highly specific aptamer recognition to recover ECL intensity with the assistance of exonuclease Ⅲ (Exo Ⅲ). As proof of concept, the "on-off-on" switch aptasensor was constructed for CEA detection with a low detection limit of 0.20 fg/mL. The principle of the constructed ECL aptasensor also enables a universal platform for sensitive detection of other tumor markers.
Developing efficient photosensitizers for C–P bond construction is highly important and remains a challenge due to the urgently needed for the synthesis of modified nucleosides, nucleotides, and other phosphine-containing ligands. Herein, two pyrene-tethered bismoviologen derivatives (Py-BiV2+) were designed and synthesized for visible-light-induced C–P bonds formation. The photochemical and electrochemical properties of Py-BiV2+ were studied systemically, certifying fine-tunable opto-electronic properties through the number of pyrene groups (4, n = 1; 6, n = 2). The prepared Py-BiV2+ showed strong light absorption, while retaining good redox features and chromic response features that were inherent to viologens. 4 exhibited accelerated photoinduced electron transfer in the presence of the electron donor (pyrene) and the generated 4' (radical cation) showed higher stability. Accordingly, Py-BiV2+ directly served as photosensitizers for the first time in the visible-light-induced C(sp3)–P and C(sp2)–P bonds formation. As expected, these novel viologen derivatives exhibited good catalytic performance and good substrate expansibility under ambient conditions.
Metal-based catalysis, including homogeneous and heterogeneous catalysis, plays a significant role in the modern chemical industry. Heterogeneous catalysis is widely used due to the high efficiency, easy catalyst separation and recycling. However, the metal-utilization efficiency for conventional heterogeneous catalysts needs further improvement compared to homogeneous catalyst. To tackle this, the pursing of heterogenizing homogeneous catalysts has always been attractive but challenging. As a recently emerging class of catalytic material, single-atom catalysts (SACs) are expected to bridge homogeneous and heterogeneous catalytic process in organic reactions and have arguably become the most active new frontier in catalysis field. In this review, a brief introduction and development history of single-atom catalysis and SACs involved organic reactions are documented. In addition, recent advances in SACs and their practical applications in organic reactions such as oxidation, reduction, addition, coupling reaction, and other organic reactions are thoroughly reviewed. To understand structure-property relationships of single-atom catalysis in organic reactions, active sites or coordination structure, metal atom-utilization efficiency (e.g., turnover frequency, TOF calculated based on active metal) and catalytic performance (e.g., conversion and selectivity) of SACs are comprehensively summarized. Furthermore, the application limitations, development trends, future challenges and perspective of SAC for organic reaction are discussed.
Difluorocarbene has emerged as a valuable intermediate to synthesize fluorides. However, difluorocarbene-derived synthesis of 19F/18F-trifluoromethyl triazoles has not been explored. Herein, we reported the Cu(I)-promoted difluorocarbene-derived 19F/18F-trifluoromethylation of iodotriazoles using KF/K18F as the fluorine source. This approach rapidly generated a wide range of 5-trifluoromethyl-1, 2, 3-triazoles in good yields showing high functional group compatibility. The reaction was effective for late-stage functionalization of bioactive molecules and 18F-trifluoromethylation of iodotriazoles. This work provides a practical synthetic methodology for the development of triazole drugs and 18F-radiotracers for positron emission tomography.
Artificial photosynthesis of valuable chemicals from CO2 is a potential way to achieve sustainable carbon cycle. The CO2 conversion activity is still inhibited by the sluggish charge kinetics and poor CO2 activation. Herein, Ag nanoparticles coupled BiOBr have been constructed by in-situ photoreduction strategy. The crafting of interface between Ag nanoparticles and BiOBr nanosheets, achieving an ultra-fast charge transfer. The BiOBr semiconductor excited electrons and plasmonic Ag nanoparticles generated high-energy hot electrons synchronous accelerates the C=O double bond activation. Thus, the optimized Ag/BiOBr-2 heterostructure shows excellent CO2 photoreduction activity with CO production of 133.75 and 6.83 µmol/g under 5 h of 300 W Xe lamp and visible light (λ > 400 nm) irradiation, which is 1.51 and 2.81 folds versus the pristine BiOBr, respectively. The mechanism of CO2 photoreduction was in-depth understood through in-situ FT-IR spectrum and density functional theory calculations. This study provides some new perspectives into efficient photocatalytic CO2 reduction.
Developing an efficient Zn-based catalyst modified with Trifluoromethanesulfonic acid (TfOH) ligand is extremely desirable for the acetylene hydration reaction. In this paper, with the use of a simple impregnation method, a series of Zn-TfOH/AC catalysts were synthesized, and the Zn-1.5TfOH/AC catalyst demonstrated the optimal catalytic performance with 96% acetylene conversion in the hydration of acetylene. The X-ray absorption fine structure (XAFS) spectra of the fresh Zn-1.5TfOH/AC catalysts demonstrated the establishment of the Zn-O4 coordination structure. According to the characterization results, TfOH ligands effectively inhibited carbon accumulation and Zinc loss, improved acidic sites and the dispersion of active metal, and produced more catalytic active site. Furthermore, the hydration reaction mechanism of Zn-TfOH/AC catalyst with Zn(OTf)2, TfO-ZnCl, and TfO-ZnOH complex configurations was explored by the Density Functional Theory (DFT) method, which showed that the activation barrier increased sequentially TfO-ZnOH < Zn(OTf)2 < TfO-ZnCl. Importantly, the OH− in TfO-ZnOH is involved in the reaction and regenerated by the dissociation of H2O, which lowers the energy barrier. This will provide a reference to design more efficient nonmercury catalysts for acetylene hydration.
The NO gas is easily oxidized to form toxic by-products (NO2) during the oxidation process, which are adsorbed on the catalyst surface and inhibit the subsequent reaction. For photocatalytic NO removal, a significant challenge is to achieve catalytic stability while maintaining high conversion efficiency. Here, we fabricated a (BiO)2CO3/β-Bi2O3 heterostructure that enables efficient charge transfer and promotes the NO removal. We propose that the catalytic stability depends on the heterojunction structure, which is able to generate interfacial charge transfer channels. In addition, we further introduce graphene quantum dots on the heterojunction structure, which further strengthens the interfacial charge transfer dynamics and finally realizes that the NO2 byproduct could gain electrons and convert to the final product (nitrite or nitrate). This composite structure not only exhibits high activity for NO removal but also maintains long-term stability under visible light.
Designing single-atom nanozymes with densely exposed metal atom active sites and enhancing catalytic activity to detect pollutants remain a serious challenge. Herein, we reported a single-atom nanozyme with layered stacked Fe/Cu dual active sites (Fe/Cu-NC SAzyme) synthesized via hydrothermal and high-temperature pyrolysis using folic acid as a template. Compared with Fe-NC and Cu-NC SAzyme, Fe/Cu-NC SAzyme has higher peroxidase-like activity, which indicates that the doping of synthesized Fe/Cu bimetals can improve the catalytic activity and that the atomic loading of Fe and Cu in Fe/Cu-NC is 5.5 wt% and 2.27 wt%, respectively. When S2− is added to the Fe/Cu-NC catalytic system, a high-sensitivity and high-selectivity S2− colorimetric sensing platform can be established, with a wide linear range (0.09–6 µmol/L) and a low detection limit (30 nmol/L), which can be used to detect S2− in environmental water samples. What's more, the Fe/Cu-NC SAzyme can activate peroxymonosulfate (PMS) to degrade 99.9% of rhodamine B (RhB) within 10 min with a degradation kinetics of 0.5943 min−1. This work details attractive applications in Fe/Cu-NC SAzyme colorimetric sensing and dye degradation.
Sodium-ion batteries (SIBs) have received significant attention in large-scale energy storage due to their low cost and abundant resources. To obtain high-performance SIBs, many intensive studies about electrode materials have been carried out, especially the cathode material. As various types of cathode material for SIBs, a 3D open framework structural Na3V2(PO4)2F3 (NVPF) with Na superionic conductor (NASICON) structure is a promising cathode material owing to its high operating potential and high energy density. However, its electrochemical properties are severely limited by the poor electronic conductivity due to the insulated [PO4] tetrahedral unit. In this review, the challenges and strategies for NVPF are presented, and the synthetic strategy for NVPF is also analyzed in detail. Furthermore, recent developments of modification research to enhance their electrochemical performance are discussed, including designing the crystal structure, adjusting the electrode structure, and optimizing the electrolyte components. Finally, further research and application for future development of NVPF are prospected.
A family of the 3, 6-branched Fuzi α-glucans including the pentasaccharide repeating unit as well as its di- and trimers were efficiently achieved via a one-pot and convergent glycosylation strategy. All the protected α-glucans up to 15-mer were assembled with high yields and excellent α-stereoselectivity, which was secured by the synergistic α-directing effects of the TolSCl/AgOTf promotion system and the steric β-facial shielding of bulky saccharide residues linked at the 6-O-position of glucosyl donors. Moreover, the 3, 6-branched architecture of glycosyl donor was revealed to be more favorable for the α-selective glucosidation of primary hydroxyl group, especially in the case of large oligosaccharide acceptor. The structurally well-defined synthetic α-glucans would be useful for various biological studies.