Crystal growth,crystal structure and pyroelectric properties of the polar hexagonal antimony tartrates MII[Sb2(C4H2O6)2]·2H2O (MII = Ca,Sr, Pb)

Single crystal growth of lead antimony tartrate dihydrate, Pb[Sb₂((+)C₄H₂O₆)₂]·2H₂O, was successfully performed. The determined polar hexagonal crystal structure is isomorphous to the corresponding calcium and strontium antimony tartrates dihydrates. New results of crystal growth and the redetermination of the crystal structures of the nonlinear optical crystal Sr[Sb₂((+)C₄H₂O₆)₂]·2H₂O and its calcium analogue are reported, together with investigations of the thermal stability and the pyroelectric properties of these polar crystals.

     

Well‐defined Sb2S3 nanostructures: citric acid‐assisted synthesis,electrochemical hydrogen storage properties

Well‐defined (three‐dimensional) 3‐D dandelion‐like Sb₂S₃ nanostructures consisted of numerous nanorods have been achieved via a facile citric acid‐assisted solvothermal process. The as‐prepared products were characterized by X‐ray diffraction (XRD), field‐emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and high‐resolution TEM (HRTEM), respectively. The influence factors of the formation of the hierarchical Sb₂S₃ nanostructures are discussed in details based on FESEM characterizations. By simply controlling the quantity of citric acid, the nucleation and growth process can be readily tuned, which brings the different morphologies and nanostructures of the final products. On the basis of a series of contrastive experiments, the aggregation‐based process and anisotropic growth mechanism are reasonably proposed to understand the formation mechanism of Sb₂S₃ hierarchical architectures with distinctive morphologies including nanorods, and dandelion‐like nanostructures. Charge‐discharge curves of the obtained Sb₂S₃ nanostructures were measured to investigate their electrochemical hydrogen storage behaviors. It revealed that the morphology played a key role on the hydrogen storage capacity of Sb₂S₃ nanostructure. The dandelion‐like Sb₂S₃ nanostructures exhibited higher hydrogen storage capacity (108 mAh g⁻¹) than that of Sb₂S₃ nanorods (95 mAh g⁻¹) at room temperature.     

High‐resolution stimulated Raman spectroscopy and analysis of the ν1 band of osmium tetroxide

We present the first high‐resolution stimulated Raman study of osmium tetroxide (OsO₄). Lines from the ν₁ totally symmetric stretching fundamental have been assigned. These data together with the infrared assignments of the ν₃ band previously recorded (M. Louviot et al., J. Quant. Spectrosc. Radiat. Transfer, 2012, 113, 119–127) allowed a refinement of the analysis of the ν₁/ν₃ stretching dyad. We found that the ν₁ band has an unusual positive isotopic shift of approximately 0.32 cm^{− 1}/amu, which gives further evidence that the stretching dyad should be perturbed by a complex nearby bending band polyad. This work is part of a global effort to analyze all fundamental bands of OsO₄ to obtain a more precise experimental value of the ground state bond length for this heavy metal‐containing molecule. The result could serve as a benchmark for high‐level quantum chemistry calculations. Copyright © 2012 John Wiley & Sons, Ltd.     

砷、锑、铋配合物的生物活性

合成新型砷、锑、铋的生物无机配合物并研究其构效关系与生物活性的作用机理,对于丰富生物无机化学内容、开发新的抗菌药和治疗肿瘤的化学药物都具有重要的意义和价值。本文简要综述了近年来砷、锑、铋的配合物在抗癌抗菌抗肿瘤等生物活性方面的应用,并展望了在该领域的应用前景。     

One-Dimensional Iodoantimonate(III) and Iodobismuthate(III) Supramolecular Hybrids with Diiodine: Structural Features,Stability and Optical Properties

Two isostructural pairs of supramolecular iodoantimonate(III) and iodobismuthate(III) complexes with I₂ units “trapped” in solid state via halogen bonding—Cat₃[[M₂I₉](I₂)} (Cat = tetramethylammonium and 1-methylpyridinium, M = Sb(III) and Bi(III)) were prepared. For all compounds, values of optical band gaps were determined, together with thermal stability; the complexes were additionally characterized by Raman spectroscopy.     

氢化物-原子荧光法测定食品容器及包装材料用聚酯树脂及其成型品中的微量锑

为建立简便、快速、高效测定食品包装材料中微量锑的方法,样品用4%乙酸处理后,利用氢化物-原子荧光法检测食品包装材料中的微量锑.结果表明,锑质量浓度在0～20 μg/L范围内呈现良好的线性,回归方程为y =87.284 C-17.440,相关系数r=0.999 9,检出限为0.028 4 μg/L,相对标准偏差RSD为0...     

Structural and spectroscopic study of chelate carbonyl and phosphoryl antimony(v) complexes

Chelate complexes of antimony tetrachloride with dibenzoylmethane and (benzoylchloro-methyl)diphenylphosphine oxide were stndicd by X-ray diffraction, I R, and Raman spectroscopy. The antimony atom has a slightly distorted octahedral coordination in the complexes. The bond lengths in the chelate cycles are evidence for an appreciable electron delocalization in the O-C-C-C-0 and O-C-C-P-0 chains. Unlike the C₃O₂Sb chelate cycle, the chelate cycle with the phosphorus atom is nonplanar. The assignment of the stretching vibrations frequencies of the C-O, P-0, C-C, Sb-O, and Sb-CI bonds was presumably made on the basis of the IR and Raman spectral data.Deceased in 1995.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1474–1479, June, 1996.     

Synthesis and structures of stiba choline bromide, [Me3SbCH2CH2OH]Br and (Me3SbCH2COO)8 (NaBr)7(MeOH)9(H2O), a supramolecular derivative of stiba betaine

The antimony analogue of choline bromide, [Me₃SbCH₂CH₂OH]Br ( 1 ), is formed by the reaction of Me₃Sb with BrCH₂CH₂OH. Crystals of (Me₃SbCH₂COO)₈(NaBr)₇(MeOH)₉(H₂O) ( 2 ) are obtained from [Me₃SbCH₂COOH]Br and Na₂CO₃ in methanol. Crystals of 1 contain stibonium cations with intramolecular coordination of the ethanolic group. The structure of 2 features supramolecular units where the carboxylic groups of stiba betaine molecules are in bridging positions between sodium ions. Copyright © 2005 John Wiley & Sons, Ltd.     

Electrical and optical properties of ceramic–polymer nanocomposite coatings

Transparent, conductive composite coatings were fabricated from suspensions of poly(vinyl acetate‐acrylic) (PVAc‐co‐acrylic) copolymer latices (50–600 nm) and nanosized antimony‐doped tin oxide (ATO) particles (～15 nm). The suspensions were deposited as coatings onto poly(ethylene terephthalate) substrates and dried at 50 °C. Microstructure studies using field emission scanning electron microscopy and tapping‐mode atomic force microscopy (TMAFM) indicated that the latex particles coalesced during drying and forced the ATO particles to segregate into the boundaries between the latex particles. Low phase contrast was observed with TMAFM; this result was consistent with the presence of PVAc‐co‐acrylic in the ATO‐rich phase of the composite. The conductivity of the composite coatings followed a percolation power‐law equation, with the percolation threshold between 0.05 and 0.075 volume fractions of ATO and the critical conductivity exponent ranging from 1.34 to 2.32. The highest direct‐current conductivity of the composite coatings was around 10^?2 S/cm. The optical transmittance and scattering behavior of the coatings were also investigated. Compared with the PVAc‐co‐acrylic coating, the composite coatings had lower transparency because of the Rayleigh scattering. The transparency of the composite coatings was improved by a reduction in the coating thickness. The best transparency for the coatings with a direct‐current conductivity of approximately 10^?2 S/cm was around 85% at a wavelength of 600 nm. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 1744–1761, 2003     

Determination of Antimony in Waters by Electrothermal Atomic Absorption Spectrometry with Preconcentration on a Tantalum Wire

 A preconcentration method for antimony in waters involving adsorption on a tantalum wire, followed by electrothermal atomic absorption spectrometry with a tungsten tube atomizer is described. The best pH for the adsorption of antimony was 2. The optimal immersing time was 120 s. Under the optimal conditions, the detection limit for antimony by the tantalum wire preconcentration method was 50 pg/mL (3S/N) and the relative standard deviation was 9.4%. The effects of large amounts of concomitants on the preconcentration of antimony were evaluated. Even though 10³–10⁴ fold excess of matrix elements existed in water, the antimony response was not significantly affected by the matrix elements. The method with preconcentration on a tantalum wire was applied to the determination of antimony in waters and proved to be sensitive, simple, and convenient. This adsorption method can be utilized in in-situ sampling of ultra-trace antimony in environmental samples (water). Furthermore, after sampling it is easy to carry and store the tantalum wire without contamination for a long time. The technique developed was shown to be useful for the determination of Sb in waste waters at the 1–5 μg/L level. Received March 20, 2002; accepted June 26, 2002