Bent Phosphaallenes With “Hidden” Lone Pairs as Ligands

Phosphaheteroallenes R−P=C=L, with L = N-heterocyclic carbenes (NHCs), can be viewed to a certain extent as phosphaisonitriles stabilized with NHCs, R−P=C:←L. The suitability of these molecules as ligands for coinage-metal ions was investigated and coordination through the central carbon center was observed in most cases. A combination of experiments, spectroscopic methods, and DFT calculations indicates the presence of a hidden electron pair at the carbon center of R−P=C:←L. Remarkably, this lone pair also inserts intramolecularly in C−H bonds showing the carbene-type reactivity which is expected for phosphaisonitriles.     

Physicochemical properties of sodium succinate sulfate and effects on BaSO4 suspension

Sodium succinate sulfate (MAPEG1500-OSO₃Na) was prepared using maleic anhydride (MA) and polyethylene glycols (PEG1500) as raw materials. The structure was characterized by Fourier transform infrared spectrometry (FTIR) and ¹H-nuclear magnetic resonance (¹H NMR). Its physicochemical properties, such as surface activity, adsorption behavior, spreading performance, and rheological property, were investigated by static/dynamic surface tension (DST) measurements, contact angle techniques, and rheological techniques at 25°C. Surface tension measurement for this surfactant is about 17?mN/m. The DST results indicated that the adsorption process is mixed diffusion-kinetic adsorption mechanism. The spreading measurement demonstrated that MAPEG1500-OSO₃Na possessed an excellent spreading ability. Besides, the dispersion performances of MAPEG1500-OSO₃Na on barium sulfate (BaSO₄) particles under different conditions have been studied by the weighing method and transmission electron microscope (TEM). These results showed that there exist optimum pH value and added amount of MAPEG1500-OSO₃Na corresponding to the highest dispersion rate.     

BSA‐IrO2: Catalase‐like Nanoparticles with High Photothermal Conversion Efficiency and a High X‐ray Absorption Coefficient for Anti‐inflammation and Antitumor Theranostics

Intrinsically integrating precise diagnosis, effective therapy, and self‐anti‐inflammatory action into a single nanoparticle is attractive for tumor treatment and future clinical application, but still remains a great challenge. In this study, bovine serum albumin–iridium oxide nanoparticles (BSA‐IrO₂ NPs) with extraordinary photothermal conversion efficiency, good photocatalytic activity, and a high X‐ray absorption coefficient were prepared through one‐step biomineralization. The nanoparticles allow tumor phototherapy and simultaneous photoacoustic/thermal imaging and computed tomography. More importantly, BSA‐IrO₂ NPs can also act as a catalase to protect normal cells against H₂O₂‐induced reactive oxygen pressure and inflammation while significantly enhancing photoacoustic imaging through microbubble‐based inertial cavitation. These remarkable features may open up the exploration iridium‐based nanomaterials in theranostics.     

Boosting Hydrogen Production by Anodic Oxidation of Primary Amines over a NiSe Nanorod Electrode

For electrocatalytic water splitting, the sluggish anodic oxygen evolution reaction (OER) restricts the cathodic hydrogen evolution reaction (HER). Therefore, developing an alternative anodic reaction with accelerating kinetics to produce value‐added chemicals, especially coupled with HER, is of great importance. Now, a thermodynamically more favorable primary amine (?CH₂?NH₂) electrooxidation catalyzed by NiSe nanorod arrays in water is reported to replace OER for enhancing HER. The increased H₂ production can be obtained at cathode; meanwhile, a variety of aromatic and aliphatic primary amines are selectively electrooxidized to nitriles with good yields at the anode. Mechanistic investigations suggest that Ni^II/Ni^III may serve as the redox active species for the primary amines transformation. Hydrophobic nitrile products can readily escape from aqueous electrolyte/electrode interface, avoiding the deactivation of the catalyst and thus contributing to continuous gram‐scale synthesis.     

Radiation-sensitive nanogel-incorporated Fricke hydrogel dosimeters with reduced diffusion rates

Fricke gel dosimeters have great potential for three-dimensional (3D) dose verification in radiation therapy; however, they suffer from time-dependent ion diffusion after irradiation, severely affecting their stability and reliability. In this work, a pullulan-based amphiphilic molecule was synthesized, characterized, and self-assembled into nanogels. Nanogel structures were embedded into gel dosimeters to reduce the diffusion rates, and radiation-sensitive nanogel-incorporated Fricke hydrogel nanocomposites were prepared successfully. The results demonstrated that the diffusion coefficient of improved dosimeters was reduced to 0.125 ± 0.001 mm² h⁻¹, while maintaining the high optical dose sensitivity (0.0410 ± 0.0004 Gy⁻¹ cm⁻¹). It provides a powerful tool toward the practical application of 3D dosimeters.     

A one-dimensional chain of polyoxometalate polymer bridged by dinuclear copper coordination units with 4-(5-phenylpyridin-2-yl)pyridine

A new Keggin polyoxometalate-based polymer, formulated as (Hppy)₂Cu₂(ppy)₄[SiMo₁₂O₄₀] (1) ppy = 4-(5-phenylpyridin-2-yl)pyridine, had been synthesized under hydrothermal conditions. Complex 1 exhibits a one-dimensional polyoxometalate-based chain constructed from Keggin anions of [SiMo₁₂O₄₀]^4? weakly connected by dinuclear [Cu(ppy)₂] groups. This complex crystallizes in the triclinic space group P-1, a = 12.621(3) Å, b = 13.168(3) Å, c = 17.467(4) Å, α = 86.09(3)°, β = 85.35(3)°, γ = 64.10(3)°, V = 2601.1(9) Å³, Z = 1. The elemental analyses, FT-IR, TG-DTA for this compound were also determined.     

An In Situ Investigation of the Protein Corona Formation Kinetics of Single Nanomedicine Carriers by Self-Regulated Electrochemiluminescence Microscopy

Protein coronas are present extensively at the bio-nano interface due to the natural adsorption of proteins onto nanomaterials in biological fluids. Aside from the robust property of nanoparticles, the dynamics of the protein corona shell largely define their chemical identity by altering interface properties. However, the soft coronas are normally complex and rapidly changing. To real-time monitor the entire formation, we report here a self-regulated electrochemiluminescence (ECL) microscopy based on the interaction of the Ru(bpy)₃³⁺ with the nanoparticle surface. Thus, the heterogeneity of the protein corona is in situ observed in single nanoparticle “cores” before and after loading drugs in nanomedicine carriers. The label-free, optical stable and dynamic ECL microscopy minimize misinterpretations caused by the variation of nanoparticle size and polydispersity. Accordingly, the synergetic actions of proteins and nanoparticles properties are uncovered by chemically engineered protein corona. After comparing the protein corona formation kinetics in different complex systems and different nanomedicine carriers, the universality and accuracy of this technique were well demonstrated via the protein corona formation kinetics curves regulated by competitive adsorption of Ru(bpy)₃³⁺ and multiple proteins on surface of various carriers. The work is of great significance for studying bio-nano interface in drug delivery and targeted cancer treatment.     

An Isolable Radical Anion Featuring a 2-Center-3-Electron π-Bond without a Clearly Defined σ-Bond

Featuring an extra electron in the π* antibonding orbital, species with a 2-center-3-electron (2c3e) π bond without an underlying σ bond are scarcely known. Herein, we report the synthesis, isolation and characterization of a radical anion salt [K(18-C-6)]⁺{[(HCNDipp)₂Si]₂P₂}⋅⁻ (i.e. [K(18-C-6)]⁺ 3 ⋅⁻) (18-C-6=18-crown-6, Dipp=2,6-diisopropylphenyl), in which 3 ⋅⁻ features a perfectly planar Si₂P₂ four-membered ring. This species represents the first example of a Si- and P-containing analog of a bicyclo[1.1.0]butane radical anion. The unusual bonding motif of 3 ⋅⁻ was thoroughly investigated via X-ray diffraction crystallography, electron paramagnetic resonance spectroscopy (EPR), and calculations by density functional theory (DFT), which collectively unveiled the existence of a 2c3e π bond between the bridgehead P atoms and no clearly defined supporting P−P σ bond.     

Extraction of quinolones from milk samples using bentonite/magnetite nanoparticles before determination by high‐performance liquid chromatography with fluorimetric detection

In this work, bentonite magnetic nanoparticles synthesized by a typical coprecipitation method were used as the adsorbent for the magnetic solid‐phase extraction of six quinolones (ciprofloxacin, difloxacin, enrofloxacin, norfloxacin, sarafloxacin, and lomefloxacin) from milk samples followed by high‐performance liquid chromatography with fluorimetric detection. Under the optimized conditions, the linear quantitation range for the six quinolones was 0.3–200 ng/mL, and the correlation coefficients of the calibration curves ranged from 0.9994 to 0.9999. The detection limit of the method was 0.1 ng/mL. Recoveries of quinolones from pure and low‐fat spiked milk samples varied from 80.4 to 92.7% and from 81.3 to 93.5%, respectively. These results demonstrated that the proposed method for the determination of six quinolones in milk samples was rapid, reliable, and efficient.     

N‐Heterocyclic Carbenes as Promotors for the Rearrangement of Phosphaketenes to Phosphaheteroallenes: A Case Study for OCP to OPC Constitutional Isomerism

The concept of isomerism is essential to chemistry and allows defining molecules with an identical composition but different connectivity (bonds) between their atoms (constitutional isomers) and/or a different arrangement in space (stereoisomers). The reaction of phosphanyl ketenes, (NHP)?P=C=O (NHP=N‐heterocyclic phosphenium) with N‐heterocyclic carbenes (NHCs) leads to phosphaheteroallenes (NHP)?O?P=C=NHC in which the PCO unit has been isomerized to OPC. Based on the isolation of several intermediates and DFT calculations, a mechanism for this fundamental isomerisation process is proposed.