聚氯乙烯膜碘离子选择电极在溴碘离子共存体系分析中的应用

介绍了聚氯乙烯膜碘离子选择电极(PVC-I-ISE)的制备方法,电极对碘离子的能斯特响应斜率为59 mV/pI,响应的线性范围为4.0×10-5~1.0×10-2mol.L-1,检出限为1.6×10-5mol.L-1,低于用银ISE的检出限,电极的使用寿命为一个月以上。将制备的碘离子选择电极作为指示电极用于对溴、碘混合离子体系进行连续分别电位滴定,并与以银电极为指示电极的电位滴定方法进行了比较。结果表明用PVC-I--ISE作指示电极,可在I--Br-共存的混合溶液中进行两离子的连续电位滴定,而用银-ISE时则不能。     

Ion chromatographic determination of iodide in urine and serum using a tubular ion-selective electrode based on a homogeneous crystalline membrane

The use of a laboratory-made iodide ion-selective electrode with tubular configuration and based on a crystalline membrane (AgI/Ag₂S) as the detector for ion chromatographic determination of iodide in urine and serum is described. A CIS reversed-phase column was coated withN-cetylpyridinium chloride to prepare a low-exchange-capacity analytical column and with hexadecyltrimethylammonium bromide to prepare a concentrator pre-column. A 2.0 ml min^–1 flow rate of deionized water and 0.1 mol 1^–1 KNO₃ solution was used for the pre-concentration and for the chromatographic separation, respectively. For optimum performance of the detector a background level of iodide was added into the column effluent. A linear relationship (r = 0.9997) between tubular electrode potential (as peak height) and iodide concentration in the range 5–400 g 1^–1 and a detection limit of 1.47 g 1^–1 were obtained. The method shows good reproducibility for both peak height (2.2% RSD) and retention time (1.3% RSD). Recoveries on its application to the samples were 93.0–100.9% for urine and 91.4–106.0% for serum.     

Synthesis, characterization and thermal properties of small R2R2NX-type quaternary ammonium halides

Twenty-one R₂R^′₂N⁺X⁻ -type (R=methyl or ethyl, R^′=alkyl, X=Br or I) quaternary ammonium (QA) halides have been prepared by using a novel one-pot synthetic route in which a formamide (dimethyl-, diethylformamide, etc.) is treated with alkyl halide in the presence of sodium or potassium carbonate. The formation of QA halides was verified with ¹H-NMR, ¹³C-NMR, MS and elemental analysis. The crystal structures of four QA halides (two bromide and two iodide) were determined using X-ray single crystal diffraction, and the powder diffraction method was used to study the structural similarities between the single crystal and microcrystalline bulk material. The thermal properties of all compounds were studied using TG/DTA and DSC methods. The smallest compounds decomposed during or before melting. The decreasing trend of melting points was observed when the alkyl chain length was increased. The liquid ranges of 120-180 °C were observed for compounds with 5-6 carbon atoms in the alkyl chain. The low melting points and wide liquid ranges suggest potential applicability of these compounds for example as ionic liquids precursors.     

Synthesis,Crystal Structure and Luminescent Property of a New Copper(Ⅰ) Iodide Complex Based on 3,5-Dimethyl-4-amino-triazole

The title compound,[Cu4I4(C4H8N4)4],has been synthesized and characterized by single-crystal X-ray diffraction analysis.It crystallizes in monoclinic,space group Pbca,with a=18.1851(10),b=9.3697(5),c=19.8034(10),V=3374.3(3)3,C16H32Cu4I4N16,Mr=1210.34,Z=4,Dc=2.383 g/cm3,μ=6.183 mm-1,F(000)=2272,S=1.032,the final R=0.0309 and wR=0.1180 for 3854 observer reflections(I2σ(I)).The structure of the title compound consists of tetranuclear copper cluster units bridged by the halogen atoms with the 3,5-dimethyl-4-aminotriazole ligands coordinated to the metal ions through the triazole nitrogen atoms.The luminescent property of 1 was also studied.     

Synthesis of the LMN-ring fragment of the Caribbean ciguatoxin C-CTX-1

Ciguatoxin C-CTX-1 was isolated as a principal causative toxin of ciguatera seafood poisoning in the Caribbean Sea, and is structurally classified as a ladder-shaped polycyclic ether. In this Letter, we report the synthesis of the tricyclic LMN-ring system of C-CTX-1. SmI₂-mediated reductive cyclization efficiently constructed the seven-membered M-ring with the axially oriented 1,3-dimethyl structure.     

A simple one-pot procedure for the direct conversion of alcohols into azides using TsIm

A facile and efficient method for one-pot conversion of alcohols into azides using N-(p-toluenesulfonyl)imidazole (TsIm) is described. In this method, alcohols are refluxed with a mixture of NaN₃, TsIm and triethylamine in the presence of catalytic amounts of tetra-n-butylammonium iodide (TBAI) in DMF affording the corresponding alkyl azides in good yields. This methodology is highly efficient for various structurally diverse alcohols with selectivity for ROH: 1° > 2° > 3°.     

催化量碘代烷烃促进下合成3,5-二取代异噁唑啉

研究了端基烯烃和醛肟在氧化剂过硫酸氢钾和催化量碘代烷烃作用下的[3+2]环合反应,合成了一系列具有良好产率及区域选择性的3,5-二取代异噁唑啉化合物.反应中,碘代烷烃先经过氧化分解产生了活泼的次碘酸,再依次与醛肟和烯烃经亲电加成反应生成五元杂环碘代中间体,该中间体通过消除反应得到3,5-二取代异噁唑啉化合物.考察了反应条件的影响,提出了可能的反应机理,为合成3,5-二取代异噁唑啉化合物提供了新方法.     

Samarium(II) iodide reduction of isoxazolidines

SmI₂ was used as reducing agent for the N-O bond cleavage in isoxazolidines. The procedure revealed is general and particularly useful for the transformation of 5-spirocyclopropane isoxazolidines to the corresponding β-aminocyclopropanols, a troublesome transformation with other known reagents.     

Synthesis and Structure of Ag(I)-Containing Coordination Polymers Based on Quaternary Ammonium Template Reagent

1 INTRODUCTION The influence of organic components on the mi- crostructures of inorganic solids has been extensively reported in recent years and shown to provide an efficacious method for the design of new materials[1～3]. Owing to their potential applications as new func- tional solid materials, interest in self-assembled co- ordination polymers with novel physical properties has grown rapidly[4～7], and many complexes like Bu4N[Ag3I4][8], {[(n-C4H9)4N]2Ag4.95Cu(I)1.05I8}n[9], [C6H…     

一种新颖一维铅碘聚合物[(Pb_2I_5)(L-H~ )·2DMF]_n(L=Piperazine)的自组装合成和晶体结构(英文)

0IntroductionIncreasinginterestisfocusedonthestudyofmagnetic,electronicandoptoelectronicpropertiesoflow鄄dimensionalorganic鄄inorganichybridcompoun鄄ds[1~3].Studiesshowthatcomplexconsistingoforganicandinorganiccomponentshavegreatpotentialforthecreationoff…