Synthesis,structures and magnetic properties of two iron(ii) tris(pyridyl)phosphine sulfide complexes

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Second-order nonlinear optical properties of CuGaxIn1-xSe2 (x = 0.54): Experimental and theoretical investigations

CuGa_xIn_1-xSe₂ (x = 0.54, CGISe) has been obtained by a high temperature solid-state method. It crystallizes in the typical chalcopyrite structure. CGISe exhibits a second-harmonic generation intensity about 0.5 times that of AgGaS₂ in the particle size range 75–100 μm. It's band structure, density of state, and optical properties are studied by theoretical calculations. The nonlinear optical properties of CGISe and several related chalcopyrite-type chalcogenides are discussed based on optical property and dipole moment calculations.     

A mild method for the synthesis of bis-pyrazolo[3,4-b:4′,3′-e]pyridine derivatives

A mild and efficient method for the synthesis of bispyrazolo[3,4-b:4′,3′-e]pyridines from 5-aminopyrazoles and aromatic aldehydes using an inexpensive FeCl₃ catalyst is reported. The reaction temperature was reduced from 220–250?°C to 130?°C compared to conventional methods. A large proportion of the products precipitated directly from the mixture at room temperature. Aliphatic and α,β-unsaturated aldehydes selectively resulted in formation of the corresponding 1H-pyrazolo[3,4-b]pyridine derivatives. A possible domino reaction mechanism was also proposed. Several aryl alkynyl groups were introduced to these tricyclic molecules via the Sonogashira coupling reaction.     

小分子共价DNA的组装及生物医学应用

DNA,由于其精确的碱基互补配对、良好的生物相容性、稳定的物理化学性质,不仅可用于组装各种形状和尺寸的纳米结构,而且可以设计动态的纳米器件。为了进一步拓展DNA的应用,可通过化学修饰引入功能分子或基团,从而实现二者功能的集成。目前,DNA与高分子、树状分子、多肽和蛋白等共价有机杂化体的合成、组装及在药物运输和控释等领域的应用已研究得比较成熟,而结构和功能多样的小分子与DNA共价杂化体,由于疏水小分子体积小,其组装受到限制,近年来科研者通过结构衍生或增多芳香环等研究其组装行为及应用。本文主要综述了疏水小分子共价连接DNA后的组装行为及其在生物医药领域的潜在应用,并对这类杂化体纳米材料的研究前景进行了展望。     

A π-Extended Pentadecabenzo[9]Helicene

A novel chiral nanographene (i.e. EP9H ) with a pentadecabenzo[9]helicene core fragment has been synthesized and fully characterized. Single-crystal X-ray diffraction unambiguously confirms the helical structure. The fluorescence emission of EP9H is located in the near infrared region (λ_em=684 nm) with a medium quantum yield (0.10) for helicene derivatives. Cyclic voltammetry reveals its seven quasi-reversible redox states from −2 to +5. Furthermore, enantiopure EP9H displays distinct CD signals in a broad spectral range from 300 to 700 nm. Notably, compared to the reported small organic molecules, EP9H displays an outstanding |g_lum| value of 4.50×10⁻² and B_CPL as 304 M⁻¹ cm⁻¹.     

MOF-808/BiOCl复合材料的制备及其光催化性能

将高稳定性的MOF-808与BiOCl结合,采用简便的水热法制备出新型MOF-808/BiOCl复合异质结材料。以环丙沙星(CIP)为污染物,探究复合材料MOF-808/BiOCl对CIP的光催化性能。发现含有10% MOF-808的复合材料(MOF-808/BiOCl-10%)表现出最佳的光催化活性。在紫外光照射20 min内,MOF-808/BiOCl-10%对CIP的光催化降解效率高达94.7%。通过X射线粉末衍射、扫描电镜、红外光谱、荧光光谱、紫外可见漫反射光谱、光电流、电化学阻抗等表征技术来考察材料的物相组成、形貌以及光电化学性质。紫外可见漫反射光谱的结果表明,MOF-808/BiOCl-10%材料光吸收范围得到提高。同时进行了自由基捕获实验。基于以上实验数据,提出了MOF-808/BiOCl复合材料可能的光催化机理。     

Submicron Li<Subscript>2</Subscript>MoO<Subscript>4</Subscript> material prepared by rheological phase method and its evaluation of lithium storage performances

In this paper, submicron Li₂MoO₄ material was synthesized via rheological phase method. The structure, composition and morphology of the obtained powders were characterized by X-ray diffraction (XRD), X-ray photoelectron spectrometer (XPS) and scanning electron microscope (SEM), respectively. The key calcination temperature was 700 ^oC. The particle sizes were about from 100 to 300 nm. As anode material of lithium ion batteries, lithium storage performances of the as-prepared Li₂MoO₄ were evaluated at different current densities. The best capacity retention was 75.7% of the initial capacity (592.13 mAh g^-1) after 50 cycles at 0.2 mA cm^-2 in 0.1-2.5 V, and the resistance was about 123.5 Ω, indicating a potential prospect in the application of lithium ions batteries.     

Speciation of inorganic selenium in environmental water samples by inductively coupled plasma optical emission spectrometry after preconcentration by using a mesoporous zirconia coating on coal cinder

A simple, novel, and selective flow‐injection solid‐phase extraction with inductively coupled plasma optical emission spectrometry method was developed for the speciation of inorganic selenium in environmental water samples. A mesoporous zirconia film was simply introduced to coat coal cinder by means of the sol–gel technique, and the adsorptive performance of the coated material for Se(IV)/Se(VI) was investigated in different media. Both Se(IV) and Se(VI) can be retained quantitatively by the material in HCl/NaOH (pH 1.0–9.0) media, while only Se(IV) was adsorbed quantitatively in sodium acetate buffer (pH 3.5–6.0). Thus, the assay of Se(VI) is based on subtracting Se(IV) from total selenium by controlling different adsorptive media without employing any redox procedure. Under the optimum conditions, the detection limit of Se(IV) is 9.0 ng/L with an enrichment factor of 100, and the relative standard deviation is 3.6% (n = 9, C = 5.0 ng/mL). The developed method was successfully applied to the speciation of inorganic selenium in environmental water samples with satisfactory results. In order to further verify the accuracy of the developed method, it was applied to analysis of total selenium in GSBZ 50031–94 certified reference environmental water, and the determined values coincided with the certified values very well.     

Ultrasensitive Immunoassay Based on Amplified Inhibition of the Electrochemical Stripping Signal of Silver Nanocomposite by Silica Nanoprobe

A silver nanocomposite was one‐step synthesized in chitosan solution and used to prepare an immunosensor with the aid of gold nanoparticles (Au NPs) assembly. The Ag NPs at the immunosensor exhibited sensitive electrochemical stripping signal in KCl solution. After a sandwich immunoreaction, the current response of the immunosensor decreased due to the formation of antibody‐antigen immunocomplex on its surface, which was greatly amplified by the captured silica nanoprobes and thus enabled an ultrasensitive electrochemical immunoassay method. This method showed excellent analytical performance for human IgG measurement including wide linear range, low detection limit, cheap cost, satisfactory reproducibility and stability.