Hydrothermal Synthesis and Crystal Structure of a New Supramolecular Channel Framework Based on Cu Complexes and Polyoxovanadate:[Cu(Ⅰ)(phen)2]5[HV15O36(Cl)]0.65[H3V16O38(Cl)]0.35·2H2O

A new compound [Cu(Ⅰ)(phen)2]5[HV15O36(Cl)]0.65[H3V16O38(Cl)]0.35·2H2O 1(phen = 1,10'-phenanthroline) has been prepared from the hydrothermal reaction of V2O5, CuCl,3:1:1:0.5:2.5:1400. Compound 1 crystallizes in the space group P42212 of the tetragonal system with a = b = 21.5009(8), c = 28.401(2) (A), V = 13129.5(12) (A)3, Z = 4, Dc = 1.800 g/cm3,μ(MoKα) =1.932 mm-1, λ.(MoKα) = 0.71073 (A), F(000) = 7063.4, C120H81.20ClCu5N20O38.7V15.35, Mr = 3557.58,the final R = 0.0594 and wR= 0.1320 for 7761 observed reflections (1 ＞ 2σ(Ⅰ)). Structure analysis shows that 1 exhibits a 3D channel framework formed by the supramolecular assembly of Cu complexes and polyoxovanadate clusters via intermolecular hydrogen bonding, and the channels contain Cu complexes. Other characterizations by elemental analysis, XPS, IR, XRD and thermal analysis are also described.     

Why heptakis(2,3-di-O-acetyl)-β-cyclodextrin can separate terbutaline enantiomers better than β-cyclodextrin: nonbonding and hydrophobic interactions

Journal of Inclusion Phenomena and Macrocyclic Chemistry - The chiral separation of terbutaline (TB) using β-cyclodextrins (β-CD) and its derivatives has aroused intensive interest....     

One-pot synthesis of NiPt core–shell nanoparticles toward efficient oxygen reduction reaction

Journal of Solid State Electrochemistry - Creating bimetallic Pt-based nanocrystals with core–shell structures has widely been recognized as the most effective way for improving their...     

Double-layer liquid crystal lens array with composited dielectric layer

ABSTRACT

A double-layer liquid crystal (LC) lens array with composited dielectric layer is proposed. In our design, a spatially non-uniform electric field is generated between the strip electrodes, resulting in a gradient refractive index distribution in the LC layer. Since the upper and lower parts of the LC lens array both adopt a composite dielectric layer, the operation voltage of the LC lens array is effectively reduced. In terms of LC lenslet, the double-layer design doubles the phase difference between the centre and the periphery of the LC layer, thereby reducing the focal length of the LC lens array. In addition, the shortest focal length (~1.78 mm) of the LC lens array is obtained at V = 3.3 V, and the LC lens array has a large focusing range.     

The distillation behavior of fluorides in LiCl–KCl molten salt

Journal of Radioanalytical and Nuclear Chemistry - The distillation behaviors of some fission product fluorides in LiCl–KCl system were investigated. For rare earth element, the corresponding...     

Ionic liquid-assisted synthesis of defect-rich BiOI with controllable structure and high surface area for excellent visible-light photocatalytic activity

In this study, BiOI materials with controllable structure are designed by using ionic liquid as I source and template to create the surface oxygen defects, thus promoting the photogenerated carrier migration and enhancing the photocatalytic activity. The texture of BiOI is controlled by adjusting the pH values of reaction mixture and the corresponding formation mechanism is also explored based on the self-assembly behavior of ionic liquid. It is found that the sample BiOI-7 possesses the ultrathin nanosheets (2 ~ 4 nm) and abundant surface oxygen defects which are beneficial for accelerating carrier transfer and facilitating photocatalytic degradation. The photocatalytic activity of as-prepared BiOI is studied by using Rhodamine B (RhB), methyl orange (MO) and Bisphenol A (BPA) as target pollutants, respectively. Besides, water splitting reactions were also used to further check the photocatalytic activity. BiOI samples exhibit the enhanced photocatalytic activity than bulk BiOI and g-C₃N₄ obtained by calcination of melamine. Especially, 92% of bisphenol A (BPA) can be degraded under light irradiation within 1 hr by using only 5 mg of BiOI-7 nanosheets, which is superior than most counterparts reported so far. This rapidly synthetic route can be applied in fabrication of other novel materials with diverse morphology and porous structure.     

In situ Synthesis of Biomimetic Silica Nanofibrous Aerogels with Temperature-Invariant Superelasticity over One Million Compressions

Resilient and compressible three-dimensional nanomaterials comprising polymers, carbon, and metals have been prepared in diverse forms. However, the creation of thermostable elastic ceramic aerogels remains an enormous challenge. We demonstrate an in situ synthesis strategy to develop biomimetic silica nanofibrous (SNF) aerogels with superelasticity by integrating flexible electrospun silica nanofibers and rubber-like Si−O−Si bonding networks. The stable bonding structure among nanofibers is in situ constructed along with a fibrous freeze-shaping process. The resultant SNF aerogels exhibit integrated properties of ultralow density (>0.25 mg cm⁻³), temperature-invariant superelasticity up to 1100 °C, and robust fatigue resistance over one million compressions. The ceramic nature also endows the aerogels with fire resistance and ultralow thermal conductivity. The successful synthesis of the SNF aerogels opens new pathways for the design of superelastic ceramic aerogels in a structurally adaptive and scalable form.     

Vacancy Engineering of Iron-Doped W18O49 Nanoreactors for Low-Barrier Electrochemical Nitrogen Reduction

The electrochemical nitrogen reduction reaction (NRR) is a promising energy-efficient and low-emission alternative to the traditional Haber–Bosch process. Usually, the competing hydrogen evolution reaction (HER) and the reaction barrier of ambient electrochemical NRR are significant challenges, making a simultaneous high NH₃ formation rate and high Faradic efficiency (FE) difficult. To give effective NRR electrocatalysis and suppressed HER, the surface atomic structure of W₁₈O₄₉, which has exposed active W sites and weak binding for H₂, is doped with Fe. A high NH₃ formation rate of 24.7 μg h⁻¹ mg_cat⁻¹ and a high FE of 20.0 % are achieved at an overpotential of only −0.15 V versus the reversible hydrogen electrode. Ab initio calculations reveal an intercalation-type doping of Fe atoms in the tunnels of the W₁₈O₄₉ crystal structure, which increases the oxygen vacancies and exposes more W active sites, optimizes the nitrogen adsorption energy, and facilitates the electrocatalytic NRR.     

Generation of α-Boryl Radicals and Their Conjugate Addition to Enones: Transition-Metal-Free Alkylation of gem-Diborylalkanes

A transition-metal-free method for the alkylation of gem-diborylalkanes with α,β-unsaturated ketones has been developed. It is demonstrated that the α-boryl radicals can be generated efficiently from gem-diborylalkanes with the aid of catechol and oxidants. The α-boryl radicals formed through such process can be engaged in conjugate addition reaction with α,β-unsaturated ketones. This transformation is a straightforward method for the synthesis of γ-borylketones.