One-dimensional and two-dimensional nanomaterials for the detection of multiple biomolecules

By utilizing nanomaterials including one-dimensional materials (1DMs) and two-dimensional materials (2DMs), the recent development for the determination of multiple biomolecules has been focused.     

Palladium-catalyzed arylation/cyclization/desulfonation cascades toward 4-aryl quinolin-2(1H)-ones with diaryliodonium salts

Palladium-catalyzed cascades of arylation/cyclization/desulfonation of ortho-aminocinnamate esters by using diaryliodonium salts afforded a wide range of 4-aryl quinolin-2(1H)-ones. As such, the desired 4-aryl quinolin-2(1H)-ones with potential biological activity has been synthesized in the yields of 34–96%.     

Copper-catalyzed cross-coupling of chloramine salts and arylboronic acids in water: A green and practical route to N-arylsulfonamides

A green and practical method for the synthesis of N-arylsulfonamides from chloramine salts and arylboronic acids is herein developed. The reaction proceeds readily in the presence of 5?mol% of CuI and 2.5?equiv. K₂CO₃ in water at room temperature, generating a variety of N-arylsulfonamides in moderate to good yields with good functional group tolerance.     

Colorimetric and ratiometric sensors derivated from natural building blocks for fluoride ion detection

Three novel colorimetric and ratiometric probes (SH-1~3) for fluoride ion detection were designed and synthesized from nature small molecules. Obvious yellow-to-orange color change of these probes in the THF was achieved only in presence of F^? among the eight anions (F^?, Cl^?, Br^?, I^?, H₂PO₄^?, HSO₄^?, CH₃COO^–, ClO₄^?), along with the emission shifting from green to orange red. These three probes are 1:1 complexed with fluoride ions, with complexation constant of around 0.1 × 10⁴ M^?1. The detection limit of probes SH-1~3 reached as low as around 1 μM. ¹H NMR titration study suggested that the fluoride ion induced deprotonation of the probe through hydrogen bonding interaction between amino group of probe and fluoride ion.     

Reductive immobilization and long-term remobilization of radioactive pertechnetate using bio-macromolecules stabilized zero valent iron nanoparticles

Reductive immobilization of radioactive pertechnetate (⁹⁹TcO₄^?) in simulated groundwater was studied by prepared carboxymethyl cellulose (CMC) and starch stabilized zero valent iron nanoparticles (nZVI), and long-term remobilization of reduced Tc was also evaluated under anoxic and oxic conditions. The stabilized nZVI can effectively reduce soluble ⁹⁹Tc(VII) to insoluble ⁹⁹Tc(IV), and they can be easily delivered into a contaminated groundwater zone and facilitate in situ remediation. In this study, CMC-stabilized nZVI showed higher reactivity than that using starch as the stabilizer. Batch experiments indicated that more than 99% of ⁹⁹Tc(VII) (C₀ = 12 mg/mL) was reduced and removed from groundwater by CMC-stabilized nZVI with a CMC content of 0.2% (w/w) at a broad pH of 5–8. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses further confirmed that ⁹⁹Tc(VII)O₄^? transformed into ⁹⁹Tc(IV)O₂ (s). The presence of bicarbonate exhibited insignificant effect on Tc immobilization, while humic acid (HA) inhibited reaction mainly due to retardation on electron transfer and formation of Tc(IV)-HA complexes. More interesting, the immobilized Tc(IV) remained insoluble even after 120 d under anoxic condition, while only ～21% was remobilized when exposed to air. Therefore, bio-macromolecules stabilized nZVI nanoparticles could be a viable alternative for in situ remediation of radioactive contamination in groundwater.     

Efficient activation of peroxymonosulfate by hollow cobalt hydroxide for degradation of ibuprofen and theoretical study

Hollow microsphere structure cobalt hydroxide (h-Co(OH)₂) was synthesized via an optimized solvothermal-hydrothermal process and applied to activate peroxymonosulfate (PMS) for degradation of a typical pharmaceutically active compound, ibuprofen (IBP). The material characterizations confirmed the presence of the microscale hollow spheres with thin nanosheets shell in h-Co(OH)₂, and the crystalline phase was assigned to α-Co(OH)₂. h-Co(OH)₂ could efficiently activate PMS for radicals production, and 98.6% of IBP was degraded at 10 min. The activation of PMS by h-Co(OH)₂ was a pH-independent process, and pH 7 was the optimum condition for the activation-degradation system. Scavenger quenching test indicated that the sulfate radical (SO₄^{? ?}) was the primary reactive oxygen species for IBP degradation, which contributed to 75.7%. Fukui index (f ^?) based on density functional theory (DFT) calculation predicted the active sites of IBP molecule for SO₄^{? ?} attack, and then IBP degradation pathway was proposed by means of intermediates identification and theoretical calculation. The developed hollow Co(OH)₂ used to efficiently activate PMS is promising and innovative alternative for organic contaminants removal from water and wastewater.     

Green synthesis and application of nanoscale zero-valent iron/rectorite composite material for P-chlorophenol degradation via heterogeneous Fenton reaction

A zero-valent iron/rectorite nanocomposite (NZVI/rectorite) was developed as a heterogeneous H₂O₂ catalyst for P-chlorophenol degradation. The physicochemical properties of NZVI/rectorite were characterized by various techniques including X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive spectrometry, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller analysis. Results showed that NZVI sphere nanoparticles were successfully loaded on the rectorite surface with less aggregation and good dispersion. Moreover, compared with acid-leached rectorite (30.91 m²/g), the NZVI/rectorite appeared to have larger surface area (50.75 m²/g). In addition, the effects of pH, reaction time, initial P-chlorophenol concentration, catalyst amount, and H₂O₂ dosage on the P-chlorophenol degradation were systematically investigated. Results showed that NZVI/rectorite presents better properties for the degradation and mineralization of P-chlorophenol compared with pristine NZVI due to the large surface area, low aggregation, and good dispersion of the former. The degradation mechanisms of P-chlorophenol by NZVI/rectorite were adsorption and reduction coupled with a Fenton-like reaction. Four successive runs of the stability and regeneration study also showed that the NZVI/rectorite were unchanged even after 100% of P-chlorophenol degradation ratio. This study has extended the application of NZVI/rectorite as environment function material for the removal of P-chlorophenol from the environment.     

Water-controlled nitro-oximation of alkenes under catalyst-free conditions

A convenient and precise nitration and oximation of alkenes with tert-butyl nitrite has been reported, yielding α-nitro ketoximes in satisfactory yields with broad substrate generality and excellent stereoselectivity under mild conditions. Experiments indicate that tert-butyl nitrite serves as both NO and NO₂ sources and water plays a key role in this difunctionalization reaction.     

Geometry,stability and aromaticity of β-diketiminate-coordinated alkaline-earth compounds

Alkaline-earth (Ae) metals have attracted a wealth of interdependent research from synthetic chemists. In Ae-catalyzed organometallic reactions, β-diketiminate is a typical ligand used to stabilize Ae catalysts by forming six-membered rings comprising Ae metals. Herein, studies focusing on the configuration of β-diketiminate-coordinated Ae compounds observed that the CC and CN bonds are homogeneous and unchanged. Furthermore, energetic studies observed that the formation of the Ae-incorporated six-membered rings results in enhanced stability of >20 kcal/mol. The nucleus-independent chemical shifts, anisotropy of the induced current density, and molecular orbital analyses demonstrated the non-aromaticity of the β-diketiminate-coordinated Ae compounds. The improved stability of these compounds can be explained by the delocalization of the π electrons derived from the β-diketiminate moiety.     

A novel synthesis of 5-substituted isoxazoles from propargylic amines and N-hydroxyphthalimide

A mild and efficient method for the synthesis of 5-substituted isoxazoles through cyclization of propargylic amines with N-hydroxyphthalimide (NHPI) under metal-free conditions was developed.     

Synthesis and electrochemical properties of Zn3V3O8 as novel anode material

Zn₃V₃O₈ two-dimensional micro sheets are successfully synthesized by combination of solvothermal method and heat treatment. The Zn₃V₃O₈ has better electrochemical performances after calcinations.     

Green synthesis of gold nanoclusters using papaya juice for detection of l-lysine

P-AuNCs was rapidly synthesized, while papaya juice served as a capping and reducing agent. Due to the surface electron density increase-induced fluorescence enhancing principle, the prepared fluorescent probe provided high selectivity and sensitivity for monitoring L-lysine in human urines.     

Metal-free synthesis of benzimidazo[1,2-c]quinazolin-6-ones with indole and benzenediamine oxidized by I2/TBHP

A variety of benzimidazo[1,2-c]quinazolin-6-ones derivatives can be accessed in moderate to good yields under simple and metal-free reaction conditions using indoles and o-benzenediamines oxidized by iodine and TBHP. This procedure works in reasonable yields for different indoles as well as o-benzenediamines thus may provide a good synthesis of quinazolinones. A TBHP oxidized ring expansion reaction mechanism that explains the synthesis of benzimidazo[1,2-c]quinazolin-6-ones were reported.     

Copper(I)-promoted trifluoromethylthiolation of arenediazonium salts with AgSCF3

An efficient method for trifluoromethylthiolation of arenediazonium salts has been developed in mild conditions with a stable and convenient AgSCF₃. It provides a straightforward and convenient way for the synthesis of trifluoromethylthiolated compound from diazonium salts in moderate to good yields.     

Stereoselective preparation of methylenecyclobutane-fused angular tetracyclic spiroindolines via photosensitized intramolecular [2+2] cycloaddition with allene

Irradiation of 3-(hexa-4,5-dienyl)indole derivatives in the presence of 3′,4′-dimethoxyacetophenone by a high-pressure mercury lamp through Pyrex glass gave the corresponding [2+2] cycloaddition products stereoselectively in high yields. The major product was a methylenecyclobutane-fused angular tetracyclic spiroindoline derivative produced by the [2+2] cycloaddition through a parallel orientation. The minor product was a hexahydromethanocarbazole derivative through a crossed orientation. Electron-withdrawing substituents, such as acyl or alkoxycarbonyl, on the indole nitrogen were suitable for this reaction.     

Nd(OTf)3-catalyzed intramolecular-intermolecular cascade cyclization reaction: An access to phenanthro[9,10-b]furan derivatives

An intramolecular-intermolecular cascade cyclization reaction via multi metal-carbene intermediates has been developed. This reaction uses catalytic amount of Nd(OTf)₃, which actives both alkyne and aldehyde moieties. This protocol provides a novel strategy for the synthesis of phenanthro[9,10-b]furans.     

A visible-light-promoted cross-dehydrogenative-coupling reaction of N-arylglycine esters with imidazo[1,2-a]pyridines

A mild and convenient visible-light-promoted cross-dehydrogenative-coupling reaction between N-arylglycine esters and imidazo[1,2-a]pyridines for the construction of CC bond was developed. A range of N-arylglycine esters and imidazo[1,2-a]pyridines were able to undergo the CDC reaction readily to afford α-heteroaryl substituted α-amino acid derivatives in good to excellent yields. A tentative mechanism for the photoredox reaction was also proposed. Importantly, the use of copper(II) salt as the sole catalyst in this visible-light-promoted transformation makes this reaction sustainable and practical.     

Photodynamic therapy based on organic small molecular fluorescent dyes

Photodynamic therapy (PDT) has shown promise as an effective treatment modality for cancer and other localized diseases due to its noninvasive properties and spatiotemporal selectivity. Near-infrared (NIR) fluorescent dyes based on organic small molecules are characterized with low cytotoxicity, good biocompatibility and excellent phototoxicity, which are widely used in PDT. In this review, we attempt to summarize the development of imaging-induced PDT based on organic small molecules and classify it according to the structures of dyes including cyanines, 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) analogues, phthalocyanine and other agents such as rhodamine analogues.     

Synthesis and characterization of mesoporous zinc layered hydroxide-isoprocarb nanocomposite

The ion exchange method was used to intercalate a poor water-soluble insecticide, isoprocarb into zinc layered hydroxide (ZLH). PXRD analysis indicated the successful intercalation with good crystallinity for the resulting nanocomposite, with a basal spacing of 33.1 Å. FTIR analyses showing the resemblance of an absorption peak of the nanocomposite with the host and the guest anion. The thermal analysis confirmed that the nanocomposite had better thermal stability compared to the pristine isoprocarb. The nanocomposite also characterized by elemental and surface morphology analysis. The surface analyses of the host and nanocomposite showed mesoporous-type material characteristics. On the whole, the intercalation process decreased the pore size of the nanocomposite compared to the pristine host, layered zinc layered hydroxide-sodium dodecyl sulphate (ZLH-SDS). The obtained material is believed has a great potential as an environmentally friendly insecticide.     

Our expedition in the construction of fluorescent supramolecular metallacycles

During the past few years, the construction of fluorescent supramolecular metallocycles has attracted extensive attention due to their diverse applications such as sensing, photoelectric devices, and mimicking complicated natural photo-processes. In this review, we will discuss how we entered the field of fluorescent supramolecular metallacycles and what we investigated in this field. The preparation of various fluorescent supramolecular metallacycles and their applications in monitoring the dynamics of coordination-driven self-assembly, sensing, catalysts, and supramolecular gels will be summarized.