Latest ArticlesTwo novel 2-(4-(9, 9-disubstitued-9H-fluoren-2-yl)phenyl)-9, 9-diethyl-1-phenyl-1, 9-dihydrofluoreno-[2, 3-d]imidazole derivatives 2a and 2b were synthesized and characterized. Their photophysical and electrochemical properties, thermal stability property, and electroluminescence (EL) performance of 2b were investigated. The fabricated device based on 2b doping into 4, 4'-N, N'-dicarbazole-biphenyl (5%) as an emitter present a maximum brightness of 1272 cd/m2 at 4 V with the CIE coordinate of (0.1590, 0.0465).
A coumarinocoumarin-based fluorescent probe, JCCA, was developed for the detection of N2H4. JCCA exhibited a fast turn-on fluorescence enhancement in response to N2H4 with good selectivity, sensitivity and a detection limit of 7.4 nmol/L. Significantly, JCCA displayed a good capability for visualizing N2H4 in living cells and zebra fish.
Radiotherapy is one of the most important clinical cancer treatments, which works mainly by delivering a prescribed radiation dose to the tumor tissues. However, high doses of radiation may also lead many irreversible damages to the surrounding normal tissues. Thereby, how to effectively reduce these sideeffects has been a significant factor in influencing cancer therapeutic effect. In this work, we synthesized the hollow PtPd nanocubes with high-index facets, and investigated the radiation protection capability in vitro and in vivo. Our results showed the PtPd nanocrystals can decrease the ROS level and improve the survival rate of radiated cells. Meanwhile, survival rate of radiated mice can significantly increase from 0 to 30% after PtPd treatment. Consequently, the enzyme and ROS level in radiated mice can be recovered.
The residues of organophosphorus pesticide (OPs) on fruits and vegetables pose a threat to human health, so it is very meaningful to explore simple and fast detect methods for OPs residual. In this work, nickel ferrite/nickel oxide nanoparticles co-loaded three-dimensional reduced graphene oxide (3DRGO-NiFe2O4/NiO NPs), as a new low cost nanocomposite, was prepared. Based on its high performance mimetic peroxidase activity, a colorimetric method for the detection of OPs has been developed. Dichlorvos was chosen as model compounds to evaluate the detection performance. The detection linear range for dichlorvos is from 50 mg/mL to 2.5×104 mg/mL with a detection limit of 10 mg/mL. Furthermore, a test paper can be developed based on the 3DRGO-NiFe2O4/NiO NPs for visual detection of dichlorvos, and the image information of the paper sensor can be converted into digital signal and quantitative detection by a smartphone. Notably, this method can also be used to detect dichlorvos in real samples, including vegetables and fruits. Thus, the developed naked assay holds great potential in simple, inexpensive and rapid detection of OPs in fruit and vegetable samples.
Interfacial electron transfer between electroactive biofilm and the electrode was crucial step for microbial fuel cells (MFCs). A three-dimensional multilayer porous sponge coating with nitrogen-doped carbon nanotube/polyaniline/manganese dioxide (S/N-CNT/PANI/MnO2) electrode has been developed for MFC anode. Here, the S/N-CNT/PANI/MnO2 anode can function as a biocapacitor, able to store electrons generated from the degradation of organic substrate under the open circuit state and release the accumulated electrons upon requirement. Thus, the mismatching of the production and demand of the electricity can be overcome. Comparing with the sponge/nitrogen-doped carbon nanotube (S/N-CNT) bioanode, S/N-CNT/PANI/MnO2 capacitive bioanode displays a strong interaction with the microbial biofilm, advancing the electron transfer from exoelectrogens to the bioanode. The maximum power density of MFC with S/N-CNT/PANI/MnO2 capacitive bioanode is 1019.5 mW/m2, which is 2.2 and 5.8 times as much as that of S/N-CNT/MnO2 bioanode and S/N-CNT bioanode (470.7 mW/m2 and 176.6 mW/m2), respectively. During the chronoamperometric experiment with 60 min of charging and 20 min of discharging, the S/N-CNT/PANI/MnO2 capacitive bioanode was able to store 10743.9 C/m2, whereas the S/N-CNT anode was only able to store 3323.4 C/m2. With a capacitive bioanode, it is possible to use the MFC simultaneously for production and storage of electricity
An efficient and practical synthetic protocol to synthesize nonsymmetrical aryl thioethers by nucleophilic aromatic substitution (SNAr) reaction of nitroarenes by thiols with potassium phosphate as the catalyst is described. Various moderate to strong electron-withdrawing functional groups are tolerated by the system to provide thioethers in a good to excellent yields. We also showed that the present method allows access to 3 drug examples in a short reaction time. Finally, mechanistic studies suggest that the reaction may form the classic Meisenheimer complex through a two-step additionelimination mechanism.
The design and preparation of luminescent M2L3 metal-organic cage via the coordination-driven selfassembly of carbazole-based ligand with a V-shaped geometry is described. The cage Zn-L1 with an open cavity which equipped aromatic rich ligands shows the highest emission quenching efficiency towards picric acid than other nitroaromatic explosives. The quenching ability depended on whether there formed the host-guest molecules are well explored by electrospray ionization mass spectrometry (ESIMS), and isothermal titration microcalorimetry (ITC).
In recent years, the transition metal-free sulfenylation of C-H bond for C-S formation has been rapidly advanced and has become an eco-friendly synthetic tool for pharmacists and organic chemists. Various natural or bioactive molecules such as (hetero)arenes, olefins, carbonyl compounds, alkanes, have been employed for sulfenylating reactions. This review will focus on the recent five-year advances in C-S bond formation via direct sulfenylation of C(sp3)-H bonds under metal-free conditions and elaborate their mechanisms from a new perspective.
2, 2, 6, 6-Tetramethyl-1-piperidinyl-N-oxyl (TEMPO) and its derivatives as stable radicals can participate in many reactions. During the process, TEMPO and its derivatives could act not only as the substrates to capture or initiate new radical intermediates to provide new compounds but also as organic catalysts or oxidants for transformations of alkenes, alcohols, aldehydes and so on to synthesize various high valueadded compounds. In this review, we would introduce recent advances of the transformations of different substrates mediated by TEMPO and its derivatives under transition-metal-free conditions.
Herein, we report a Pd-catalyzed mono-α-arylation reaction for pyridine benzylic functionalization. This approach serves as an efficient alternative to synthesize di-heteroaryl acetates in good yields and selectivities. Moreover, the method is applicable to heteroaryl substrate combinations, and exhibits great functional group tolerance. A streamlined protocol also enables the rapid synthesis of diheteroaryl ketones. The synthetic value was also demonstrated by scale-up experiments