Latest ArticlesAn efficient and scalable electrochemical asymmetric protocol with metal-free catalysts and even without additional oxidants for the cross-dehydrogenative coupling reaction (CDC) of two C(sp3)-H bonds is reported. A series of aldehydes including natural products and various substrates containing C(sp3)-H bonds including xanthenes, acridines, cycloheptatrienes and even diarylmethane have been shown to undergo asymmetric CDC to afford a series of carbon-carbon bond coupling products with up to 94% yield and 98% ee. Mechanistic studies such as radical clock experiment suggest that the reaction proceeds via nucleophilic attack by enamine under electrochemical conditions.
A simple and additive-free protocol has been developed for the preparation of β-keto phosphorodithioates through the three-component reaction of easily available sulfoxonium ylides, P4S10, and alcohols. The present geminal hydro-phosphorodithiolation reaction was performed at room temperature to construct a series of β-keto phosphorodithioates in the absence of any metal reagents, bases, or additives.
Biomass absorbing materials have received increasing attention for electromagnetic wave (EMW) absorption field absorbing materials due to its low density and high dielectric loss. However, the biomass EMW absorbing materials often suffer from the insufficient magnetic loss and impedance matching. In this work, a facile ZIF-8/ZIF-67-derived biomass composites (CoZnO@BPC) was prepared for high-performance EMW absorption based on multi-component micro, nano structures metal particles and xanthoce sorbifolia bunge shells-derived biomass porous carbon (BPC). The dielectric loss and/or magnetic loss abilities of CoZnO@BPC composites were adjusted by changing the mass ratio of Zn2+ to Co2+ ions. Under the filled amount of 20 wt%, CoZnO@BPC exhibited excellent EMW absorption with the minimum reflection loss (RL) at 15.84 GHz is -50.2 dB, and the matching thickness is only 1.7 mm. By adjusting the ZIFs mass ratio, the effective absorption bandwidth (EAB) can be up to 5.92 GHz (from 12.08 GHz to 18 GHz), and the matching thickness is only 1.9 mm. The results provide a new insight for the economical and efficient preparation of lightweight and advanced microwave absorbing materials.
Semiconductor-molecule surface-enhanced Raman scattering (SERS), especially the stronger interfacial charge transfer process (ICTP), represents a frontier in the field of SERS with spectral reproducibility and unparalleled selectivity. Herein, through a laser microfabrication method in situ, the free-standing, super hydrophilic and vacancy-rich TiO2-x/Ti is successfully synthesized. Using blue TiOx/Ti (B-TiOx/Ti) as pre-concentrated substrate, a nanomolar-level limit of detection of 12 nmol/L at 1385 cm–1, is confirmed using crystal violet (CV) bacteriostat as a model under 532 nm excitation. Furthermore, the results demonstrate that the SERS enhancement mechanism is via the moderate adulteration of oxygen vacancy, which leads to a narrow value of band gap and increases the ICTP of substrate to molecules. Using a hand-held extractor assembled with B-TiOx/Ti microfiber, the operando analysis of mixtures distributed information excited in different parts of Asian carp is facilely achieved. This work guides the controlled synthesis of vacancy-rich TiO2-x/Ti nanostructure and its application in ultrasensitive extraction-SERS detection. It also provides the direction for the rapid and operando transmission of biological information with temporal and spatial concentration distribution in human tissues by highly sensitized materials.
We describe a versatile electrophile addition/SPR sequence of readily available cyclopropyl carbinols that affords multi-substituted carbonylated cyclopropanes with high stereo-fidelity. This approach tolerates various heteroatom electrophiles, migration of carbon moiety of all possible hybridization states, facile ring reorganization and natural compound valorization. The examples represent an unprecedented version of SPR wherein migration to a non-benzylic bulky tertiary carbo-cation is realized with promising enantiocontrol.
The Na-deficient P3-type layered oxide cathode material usually experience complex in-plane Na+/vacancy ordering rearrangement and undesirable P3-O3 phase transitions in the high-voltage region, leading to inferior cycling performance. Additionally, they exhibit unsatisfactory stability when exposed to water for extended periods. To address these challenges, we propose a Cu/Ti co-doped P3-type cathode material (Na0.67Ni0.3Cu0.03Mn0.6Ti0.07O2), which effectively mitigates Na+/vacancy ordering and suppresses P3-O3 phase transitions at high voltages. As a result, the as-prepared sample exhibited outstanding cyclic performance, with 81.9% retention after 500 cycles within 2.5–4.15 V, and 75.7% retention after 300 cycles within 2.5–4.25 V. Meanwhile, it demonstrates enhanced Na+ transport kinetics during desodiation/sodiation and reduced growth of charge transfer impedance (Rct) after various cycles. Furthermore, the sample showed superb stability against water, exhibiting no discernible degradation in structure, morphology, or electrochemical performance. This co-doping strategy provides new insights for innovative and prospective cathode materials.
Multicharged supramolecular assemblies based on luminescent macrocycle play an important role in extending their optical properties and functions. Herein, we reported macrocyclic supramolecular assemblies based on luminescent terphen[3]arene sulfate (TP[3]AS) and tetraphenylethylene pyridinium (TPE-4Py) through electrostatic interactions, host-guest encapsulation and π-π stacking interactions. Förster resonance energy transfer (FRET) process from TP[3]AS to TPE-4Py was achieved with the energy transfer efficiency of 99.9%, accompanied by TPE-4Py fluorescence emission bathochromic shifted of 15 nm and enhanced by 1.68 times in PBS solution. In contrast, other non-luminescent sulfato-β-cyclodextrin and sulfobutylether-β-cyclodextrin only can enhance the fluorescence intensity of TPE-4Py without bathochromic shift. Due to the strong fluorescence and good stability of TPE-4Py@TP[3]AS, it can be used for optical imaging in living cells, which provided an effective approach for the construction of assembling-confined luminescent biomaterials.
A highly site-selective intermolecular trifluoromethylimination of activated and unactivated olefins was reported under transition-metal- and photosensitizer-free conditions. This newly developed strategy provides straightforward and efficient access to diverse value-added vicinal trifluoromethyl amines without resorting to the pre-functionalized reagents. Mechanistic experiments demonstrate that the approach proceeded through CF3 and iminyl two-radicals process, which were generated directly from commercially available benzophenone imine in a novel electron-donor mode via a SET process activated by the bifunctional hypervalent iodine reagents. The synthetic potential of the protocols was further showcased via the condensation/amination sequential cascade, and transformations to access β-CF3 primary amines.
In this work, we established an exceptionally facile method for the preparation of Ni-CeO2 nanorods in a kind of deep eutectic solvents (DESs) composed of L-proline and Ce(NO3)3·6H2O. First, Ni-CeO2 nanorods were successfully prepared by adding Ni(NO3)3·6H2O to DESs. Then, we found that Ni-CeO2 nanorods prepared in DESs have more prominent oxidase-like activity than pure CeO2. The outstanding catalytic activity of Ni-CeO2 could be ascribed to its high Ce3+/Ce4+ ratio. As a proof-of-concept application, the Ni-CeO2 nanorods were successfully acted as a colorimetric platform for the sensitive determination of ascorbic acid and α-glucosidase activity, which displays excellent analytical performance. Moreover, this sensing platform was applied for screening natural α-glucosidase inhibitors, such as terpenoids from natural products. The results indicated that ursolic acid and oleanolic acid had good inhibitory rates. This strategy not only provides a new way to construct more kinds of nanomaterials from DESs, but also offers a facile and effective tool to screen the α-glucosidase natural inhibitors as potential anti-diabetic drugs.
Photosynthesis is the process through which living plants utilize photosynthetic pigments, such as chlorophyll, to convert CO2 and water into organic compounds and release O2 under visible light. In this study, we have successfully constructed a fluorescent supramolecular polymer (P5Py2/Zn/Gen)n by employing orthogonal pillar[5]arene-based molecular recognition and metal ion coordination. Within the supramolecular polymer, the guest molecule Gen unit acts as a light-harvesting moiety, as the ACQ effect is inhibited by host-guest interactions, while the (Py)2/Zn center serves as a catalytic site. By employing this orthogonal self-assembly strategy, we have enhanced the stability of both the donor and acceptor in catalyzing the reduction of p-nitrophenol to p-aminophenol. Moreover, this photocatalyst can be reused at least 5 times without significant conversion loss. These findings provide a pathway for constructing a recyclable artificial LHS that mimics the entire photosynthesis process.