Viscosity B-coefficients of the aqueous cyanide and azide ions

A number of factors have led us to re-examine the literature assignments of the viscosity B-coefficients of the individual cyanide and azide ions in aqueous solutions at 25°C. The revised values, obtained from mutually confirmatory correlations, are: B(CN^–)=–0.020±0.007 and B(N ₃ ^– )=–0.014#±#0.006>dm³-mol^–1     

2-羟基萘甲醛苯腙衍生物对氟阴离子的高选择性裸眼识别

合成了3种2-羟基萘甲醛苯腙衍生物[1～3;取代基R:H(1),p-NO2(2),2,4-d-NO2(3)],应用紫外-可见吸收光谱研究了其与阴离子的相互作用,通过改变N1-苯环取代基考察了受体分子对阴离子亲合力和选择性的影响.结果表明,乙腈中F-及CH3COO-等阴离子使受体分子吸收光谱发生显著变化,溶液的颜色由黄色...     

Synthesis of silver nanowires and their applications in the electrochemical detection of halide

A silver nanowires modified platinum (Ag NWs/Pt) electrode was developed for simultaneous and selective determination of chloride, bromide and iodide ions by cyclic voltammetry in aqueous solutions. Silver nanowires were synthesized by an l-cysteine-assisted poly (vinyl pyrrolidone) (PVP)-mediated polyol route. X-ray diffraction (XRD) and scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) were employed to investigate the prepared nanowires. The intrinsic high surface area and the fast electron transfer rate ascribed from the nanowire structure could further improve halide detection performance. The determination was based on measurement of the well-separated oxidation peak currents of respective silver halides formed on the surface of silver during an anodic potential sweep. The concentration range was linear from 50 μM to 20.2 mM for bromide and iodide and 200 μM to 20.2 mM for chloride, and the sensitivity was 0.059 μA/mM, 0.042 μA/mM and 0.032 μA/mM for chloride, bromide and iodide, respectively. The correlation coefficient was 0.999 in each case. The Ag NWs/Pt electrode offered a useful platform for the development of a highly sensitive halide sensor.     

Moderate and advanced intramolecular proton transfer in urea-anion hydrogen-bonded complexes

The study of the interactions of the three urea-based receptors AH, BH(+) and CH(2+) with a variety of anions, in MeCN, has made it possible to verify the current view that hydrogen bonding is frozen proton transfer from the donor (the urea N-H fragment in this case) to the acceptor (the anion X(-)). The poorly acidic, neutral receptor AH establishes two equivalent hydrogen bonds N-H···X(-), with all anions, including CH(3)COO(-) and F(-), in which moderate proton transfer from N-H to the anion takes place. The strongly acidic, dicationic receptor CH(2+) forms, with most anions, complexes in which two inequivalent hydrogen bonds are present: one involving moderate proton transfer (N-H···X(-)) and one in which advanced proton transfer has taken place, described as N(-)···H-X. The degree of proton advancement is directly related to the basic tendencies of the anion. The cationic receptor BH(+) of intermediate acidic properties only forms complexes with two inequivalent hydrogen bonds (moderate+advanced proton transfer) with CH(3)COO(-) and F(-), and complexes with two equivalent hydrogen bonds (moderate proton transfer) with all the other anions. Moreover, [B···HF] and [C···HF](+), on addition of a second F(-) ion, lose the bound HF molecule to give HF(2)(-). Release of CH(3)COOH, with the formation of [CH(3)COOH···CH(3)COO](-), also takes place with the [B···CH(3)COOH] complex in the presence of a large excess of anion.     

Radical polymerization of 1‐alkenes catalyzed by lithium salts of carboranes

Radical polymerization of selected 1‐alkenes, (1‐hexene, 1‐octene and 2‐methyl‐1‐heptene), initiated with classical radical initiators and catalyzed by lithium salts of selected carboranes was studied. In accordance with recently published results it was found that the use of radical initiators under catalysis by “naked” lithium cation of carboranes promotes the radical polymerization of 1‐alkenes, otherwise nonpolymerizable by the radical mechanism. However, although in our experiments relatively high monomers conversions are reached for some of the thermal initiators used, only low‐molecular‐weight oligomers with M_n < 1000 are formed, regardless of the initiator and carborane anion used. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

四溴合铜(Ⅱ)-对溴苄基吡啶鎓盐的合成和晶体结构

通过CuBr和[4-BrBzPy]Br([4-BrBzPy]+为1-(4′-溴苄基)吡啶鎓离子;Py为吡啶)直接在含氢溴酸的乙腈中反应得到了一种新的吡啶鎓盐[4-BrBzPy]2[ CuBr4].用元素分析、红外光谱、电子喷雾质谱和X-射线衍射表征了其组成和结构.所合成的吡啶鎓盐由1个四面体形的[ CuBr4]2-阴离...     

SiO44-对Li3Sc2(PO4)3快离子导体的阴离子替代效果研究

Li3Sc2(PO4)3因具有有利的离子传导通道、低的电子电导率和高的稳定性而成为全固态锂离子电池用固体电解质最具竞争力的材料之一,然而这一化合物只有在245℃以上的γ相才具有快离子传导特性。人们主要采用Zr4+、Ti4+等阳离子部分取代其中的Sc3+以改善材料的室温电导率,有关该化合物PO43-阴离子替代的报道还很少。本研究试图利用机械研磨技术,通过向Li3Sc2(PO4)3原料混合物中加入适量SiO2,以期能够实现对该化合物的部分阴离子替代。研究结果表明:所制备的Li3+xSc2(PO4)3-x(SiO4)x(x=0~0.6)系列化合物在x=0.15时电导率达到最大值,σ298=9.55×10-4 S.m-1,离子传导激活能达到最小值45.06 kJ.mol-1。29Si MAS-NMR测试结果证实所加入的SiO2主要以[SiO4]四面体形式存在替代Li3Sc2(PO4)3中部分[PO4]四面体。     

Anion‐binding properties of two calix[4]arene derivatives containing two ferrocene imine or ferrocene amine units at the upper rim

Calix[4]arene derivatives containing ferrocene units at the upper rim have been synthesized and their anion‐binding and sensing investigated towards anions such as chloride, bromide and hydrogen sulfate by cyclic voltammetry. Electrochemical studies show that these redox‐active ligands electrochemically recognize chloride and bromide anions. These compounds have excellent selectivity for chloride and bromide ions, in the comparison with hydrogen sulfate anion. With ferrocenyl Schiff base calix[4]arene 1 an anodic shift as large as 302 mV is observed on addition of four equivalents of Cl⁻ anion. Also electrochemical and UV–vis spectroscopic titrations ferrocenyl calix[4]arene derivatives 1 with chloride and bromide ions and 2 (only with Cl⁻) indicate a 1:1 binding‐stiochiometry. Copyright © 2011 John Wiley & Sons, Ltd.     

Met.(Cu,Ag)-TCNQ有机薄膜的EB CL像

自从1979年Potember等人首先发现了CuTCNQ有机薄膜具有受电流控制的电开关特性以来[1]，有关CuTCNQ及AgTCNQ这些阴离子基过渡金属盐（以下简称为Met．（CU、Ag）-TCNQ）有机薄膜的光存储特性、光电开关特性，以及某些气教特性的研究结果便不断报导出来[2-4]，引起人们极大的兴趣．作为很有前途的有机光电功能材料，至今对其电导及光电特性的机理研究仍显得十分薄弱，极大影响了它们进一步向实用器件方向的发展．由于CuTCNQ的晶体参数至今未见报导，我们依据CuTCNQ粉末X射线小角衍射谱对比AgTCNQ相应的粉末X射线衍射数据，…     

Direct fabrication of conductive LB films composed of N-docosylpyridinium-TCNQ

Langmuir-Blodgett (LB) films of N-docosylpyridinium-TCNQ (NDP-TCNQ) were prepared in air. The films deposited at the room temperature showed in-plane conductivity of 4×10-3 S.cm-1 and its absorption spectra in UV and IR regions resembled those for the films composed of mixed-valence TCNQ salts of NDP-(TCNQ)2 rather than for the NDP-TCNQ LB films preparaed under protection of nitrogen. In the case that the films left in a warm environment after each dipping cycle, the absorption in the corresponding region changed. Spectral analysis and XPS study revealed that more TCNQ molecules were produced. The oxidation of TCNQ- in air was considered to be the origin of neutral TCNQ formed.