基于杂环有机锡化合物的水杨酸根离子选择电极研究

A novel heterocyclic haxacoordinated organotin(Ⅳ) complex, bis (o-vanillin)-semi-ethylenediamine dibenzyltin (VEDBT) was synthesized and used as anion ionophore for PVC membrane electrode; the novel electrode exhibits a linear response towards salicylate and an anti-Hofmeister selectivity pattern with high specificity for salicylate over many common anions, the selective pattern is: Sal^- > SCN^- > ClO₄^- > I^- > NO₂^- > NO₃^- > Cl^- ≈ Br^- > SO₄^2-. The behaviour of the electrode is influenced by the experimental conditions. The response mechanism was also investigated by UV spectroscopy. The electrode was applied to the determination of salicylate in pharmaceutical samples with satisfactory results.     

新型三脚架苯甲醛苯腙醋酸根选择性比色化学传感器

本文合成了一个新的基于三脚架苯甲醛苯腙的能够选择地检测醋酸根离子的比色化学传感器1。用紫外可见吸收光谱证实了受体1在二甲基亚砜溶液中对醋酸根离子高选择的键合能力超越了其它阴离子。和其他所研究的阴离子相比,其在二甲基亚砜中紫外可见吸收光谱对具有高选择性醋酸根离子的存在显示了应答,当存在（2´10^-5mol·dm^-3）醋酸根离子时其溶液的颜色也由黄色变化到蓝色。当用其他不同的客体阴离子（F^-, Cl^-, Br^-, I^-, H₂PO₄ ^–和 OH^-）处理受体1时,仅出现了很小的紫外可见吸收光谱变化。受体1对醋酸根的结合常数 K_ass为1.69´ 10⁴。     

抗衡阴离子PF6-调控的1, 3-丙二胺缩邻香兰素镧(Ⅲ)配合物的合成和晶体结构

通过柔性配体1, 3-丙二胺缩邻香兰素(H₂L)与和La(NO₃)₃·6H₂O反应, 合成了1个由2个H₂L桥连的双核稀土配合物[La₂(NO₃)₆(H₂L)₂] ·CH₂Cl₂ (1), 该配合物与(NH₄)(PF₆)继续反应生成了1个由2个NO₃^-离子桥连的双核配合物[La₂(NO₃)₂(H₂L)₄] (PF₆)₄·4H₂O·2CH₂Cl₂ (2), X-射线单晶衍射分析确定了2个配合物的晶体结构。配合物1和2为结构完全不同的2个双核结构, 因抗衡阴离子PF₆^-有去阴离子的作用, 配合物1中的NO₃^-离子被配体取代, 导致配合物1的结构翻转, 形成了1个新颖的双核结构2。     

NO2-对乳酸-丙酮-BrO3--Mn2+-H2SO4化学振荡反应的影响

研究NO₂^-对乳酸-丙酮-BrO₃^--Mn²⁺-H₂SO₄化学振荡反应的影响时发现,NO₂^-对振荡反应的诱导期t_in、周期t_p有显著的影响。NO₂^-的浓度C_NO2^-与诱导期倒数的对数ln(1/t_in)、NO₂^-浓度的对数lnC_NO2^-与周期的对数lnt_p均有良好的线性关系,线性范围为7.46×10^-5～2.99×10^-3mol·L^-1。在此浓度范围内,NO₃^-无影响,是一重现性好,灵敏度高,操作简单的NO₂^-动力学分析测试体系。获得诱导期、周期的表观活化参数E_in、E_p分别为56.82kJ·mol^-1、64.51kJ·mol^-1。结合被动采样法,测得室外大气中NO₂日平均浓度值为1.59×10^-9mol·L^-1,最后对NO₂^-共存时的振荡反应诱导期机理进行了初步探讨。     

用鲁米诺-KIO4-Fe(1, 10-phen)32+体系的化学发光法测定痕量铁

本文利用鲁米诺-KIO₄-Fe(1,10-phen)₃²⁺配合物体系产生化学发光反应,建立了测定痕量铁的新的化学发光分析方法.该法以1,10-phen为配位体,铁的检出限为1.6×10^-7g/L,工作曲线响应浓度范围在1×10^-5-1×10^-3g/L.在测定2×10^-4g/L铁的相对标准偏差为3.5%.用于检测工业沉淀BaSO₄中痕量铁获得满意结果.     

基于咪唑基配体的Mn(Ⅱ)配合物的水热合成及结构、理论计算和三阶非线性光学性质

在水热条件下用氯化锰和咪唑基配体合成了配合物Mn[（IPB）₂Cl₂]·4H₂O （IPB=4-（1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl） benzaldehyde）,并通过元素分析、红外光谱、紫外衍射、X射线单晶衍射法和Z-扫描技术对其结构和性质进行了表征。X射线单晶衍射结果表明,该化合物晶体属正交晶系,空间群Pnna。采用Z-扫描技术测量了该化合物的非线性光学特性,结果显示,以45 μJ的脉冲能量,在焦点处的透光率为93%,非线性吸收系数为-4.5×10^-11 m·W^-1,非线性折射率为1.0×10^-19 m²·W^-1。该化合物显示了自聚焦的性质。在紫外-可见光谱区,该化合物的最大吸收波长为282nm。     

基于咪唑基配体的Mn(Ⅱ)配合物的水热合成及结构、理论计算和三阶非线性光学性质

在水热条件下用氯化锰和咪唑基配体合成了配合物Mn[（IPB）₂Cl₂]·4H₂O（IPB=4-（1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl）benzaldehyde）,并通过元素分析、红外光谱、紫外衍射、X射线单晶衍射法和Z-扫描技术对其结构和性质进行了表征。X射线单晶衍射结果表明,该化合物晶体属正交晶系,空间群Pnna。采用Z-扫描技术测量了该化合物的非线性光学特性,结果显示,以45 μJ的脉冲能量,在焦点处的透光率为93%,非线性吸收系数为-4.5×10^-11 m·W^-1,非线性折射率为1.0×10^-19 m²·W^-1。该化合物显示了自聚焦的性质。在紫外-可见光谱区,该化合物的最大吸收波长为282nm。     

以单环有机锡配合物为载体的水杨酸根阴离子选择电极的研究

Two new cyclic pentacoordinative organotin(Ⅳ) complexes, 2,4-dihydroxyacetophenone tribenzyltin(HAPTBT) and 2,4-dihydroxyacetophenone triphenyltin(HAPTPT) were synthesized and used as anion ionophore for PVC membrane electrode. The new electrodes exhibit specificity selectivity for salicylate. The electrode based on HAPTBT as a neutral carrier displays a highly potentiometric response to salicylate and an anti-Hofmeister selectivity sequence in the following order: Sal^- ＞ SCN^- ＞ I^- ＞ NO₂^- ＞ Br^- ＞ Cl^- ＞ ClO₄^- ＞ NO₃^- ＞ SO₄^2-. The electrode has the advantages of fast response, stability and reproducibility, simplicity. The response mechanism is discussed in view of UV spectroscopy technique. The results show that there are close relationship between the potentiometric response characteristics and structure of organotin(Ⅳ) complexes. The electrode was applied to medicine analysis with satisfactory results.     

吡啶取代苯酚配体构建的三个配合物的晶体结构

以2-（N，N-二（2-吡啶甲基）氨甲基）-6-醛基-4-甲基苯酚（HL）为配体合成了一个新的双核钙配合物[Ca₂L₂（NO₃）₂]（1）和一个单核镉配合物[Cd（HL）（NO₃）₂]（2），在碱性条件下，2能转化为双核镉配合物[Cd₂L₂（NO₃）₂]·H₂O（3）。分别对它们进行了红外、质谱、元素分析和单晶结构表征。配合物1和3属于单斜晶系，空间群分别为P2₁/c和C2/c，配合物2属于三斜晶系，空间群为P1。单晶结构表明，配合物1含有一个酚氧桥连的双核钙单元[Ca₂O₂]，每个钙均为八配位的扭曲十二面体构型[CaN₃O₅]，配位原子分别来自一个配体L^-的3个氮原子和一个酚氧原子、另一个配体L^-的一个酚氧原子和一个醛氧原子以及一个硝酸根的2个氧原子。2是一个单核镉配合物，八配位镉的配位构型是扭曲的十二面体[CdN₃O₅]，配位原子分别来自配体HL的3个氮原子和一个酚氧原子以及2个硝酸根的4个氧原子，醛基不参与配位。配合物3含有一个酚氧桥连的双核镉单元[Cd₂O₂]，每个镉均为七配位的单帽三棱柱构型[CdN₃O₄]，配位原子分别来自一个配体L^-的3个氮原子和一个酚氧原子、另一个配体L^-的一个酚氧原子和一个醛氧原子以及一个硝酸根的一个氧原子。     

离子对UIO-66-2OH光催化性能的影响

实际废水中存在的离子会对有机污染物的光催化降解产生影响。以ZrCl₄和2,5-二羟基对苯二甲酸为原料,通过水热合成法成功制备了金属有机骨架材料UIO-66-2OH。通过红外（IR）、X射线粉末衍射（XRD）、X射线光电子能谱（XPS）和扫描电子显微镜（SEM）对UIO-66-2OH的结构进行表征。利用水中常见的金属阳离子和无机阴离子,探索UIO-66-2OH的光催化性能。研究发现,金属阳离子Fe³⁺和无机阴离子HCO₃^-、CO₃^2-可以加快光催化降解的速度。然而,金属离子Na⁺、K⁺、Ca²⁺、Mg²⁺、Cu²⁺和无机阴离子Cl^-、SO₄^2-、PO₄^3-会抑制光催化性能,且离子价态越高,抑制效果越明显。     

Highly Selective Salicylate Membrane Electrode Based on N,N＇- （Aminoethyl）ethylenediamide Bis（2-salicylideneimine） Binuclear Copper（Ⅱ） Complex as Neutral Carrier

A new ion selective electrode for salicylate based on N,N＇-（aminoethyl）ethylenediamide bis（2-salicylideneimine） binuclear copper（Ⅱ） complex [Cu（Ⅱ）2-AEBS] as an ionophore was developed. The electrode has a linear range from 1.0 × 10^-1 to 5.0 ×10^-7 mol·L^- 1 with a near-Nemstian slope of （ - 55 ±1 ） mV/decade and a detection limit of 2.0 × 10-7 mol·L^-1 in phosphorate buffer solution of pH 5.0 at 25 ℃. It shows good selectivity for Sal^- and displays anti-Hofmeister selectivity sequence： Sal^-〉SCN^-〉 ClO4^- 〉I^-〉 NO2^- 〉Br^-〉 NO3^- 〉Cl^-〉 SO3^2- 〉 SO4^2- The proposed sensor based on binuclear copper（Ⅱ）complex has a fast response time of 5-10 s and can be used for at least 2 months without any major deviation. The response mechanism is discussed in view of the alternating current （AC） impedance technique and the UV-vis spectroscopy technique. The effect of the electrode membrane compositions and the experimental conditions were studied. The electrode has been successfully used for the determination of salicylate ion in drug pharmaceutical preparations.     

Rate constants for the gas‐phase reactions of nitrate radicals with geraniol,citronellol, and dihydromyrcenol

Terpenes and terpene alcohols are prevalent compounds found in a wide variety of consumer products including soaps, flavorings, perfumes, and air fresheners used in the indoor environment. Knowing the reaction rate of these chemicals with the nitrate radical is an important factor in determining their fate indoors. In this study, the bimolecular rate constants of k (16.6 ± 4.2) × 10^?12, k (12.1 ± 3) × 10^?12, and k (2.3 ± 0.6) × 10^?14 cm³ molecule^?1 s^?1 were measured using the relative rate technique for the reaction of the nitrate radical (NO₃?) with 2,6‐dimethyl‐2,6‐octadien‐8‐ol (geraniol), 3,7‐dimethyl‐6‐octen‐1‐ol (citronellol), and 2,6‐dimethyl‐7‐octen‐2‐ol (dihydromyrcenol) at (297 ± 3) K and 1 atmosphere total pressure. Using the geraniol, citronellol, or dihydromyrcenol + NO₃? rate constants reported here, pseudo‐first‐order rate lifetimes (k′) of 1.5, 1.1, and 0.002 h^?1 were determined, respectively. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 669–675, 2010     

2–Butoxyethanol and benzyl alcohol reactions with the nitrate radical: Rate coefficients and gas‐phase products

The bimolecular rate coefficients k and k were measured using the relative rate technique at (297 ± 3) K and 1 atmosphere total pressure. Values of (2.7 ± 0.7) and (4.0 ± 1.0) × 10^?15 cm³ molecule^?1 s^?1 were observed for k and k, respectively. In addition, the products of 2‐butoxyethanol + NO₃^? and benzyl alcohol + NO₃^? gas‐phase reactions were investigated. Derivatizing agents O‐(2,3,4,5,6‐pentafluorobenzyl)hydroxylamine and N, O‐bis (trimethylsilyl)trifluoroacetamide and gas chromatography mass spectrometry (GC/MS) were used to identify the reaction products. For 2‐butoxyethanol + NO₃^? reaction: hydroxyacetaldehyde, 3‐hydroxypropanal, 4‐hydroxybutanal, butoxyacetaldehyde, and 4‐(2‐oxoethoxy)butan‐2‐yl nitrate were the derivatized products observed. For the benzyl alcohol + NO₃^? reaction: benzaldehyde ((C₆H₅)C(?O)H) was the only derivatized product observed. Negative chemical ionization was used to identify the following nitrate products: [(2‐butoxyethoxy)(oxido)amino]oxidanide and benzyl nitrate, for 2‐butoxyethanol + NO₃^? and benzyl alcohol + NO₃^?, respectively. The elucidation of these products was facilitated by mass spectrometry of the derivatized reaction products coupled with a plausible 2‐butoxyethanol or benzyl alcohol + NO₃^? reaction mechanisms based on previously published volatile organic compound + NO₃^? gas‐phase mechanisms. © 2012 Wiley Periodicals, Inc.

1 This article is a U.S. Government work and, as such, is in the public domain of the United States of America.

© 2012 Wiley Periodicals, Inc. Int J Chem Kinet 44: 778–788, 2012     

A kinetic study of the gas‐phase reactions of OIO with NO,NO2, and Cl2

The kinetics of iodine dioxide (OIO) reactions with nitric oxide (NO), nitrogen dioxide (NO₂), and molecular chlorine (Cl₂) are studied in the gas‐phase by cavity ring‐down spectroscopy. The absorption spectrum of OIO is monitored after the laser photodissociation, 266 or 355 nm, of the gaseous mixture, CH₂I₂/O₂/N₂, which generates OIO through a series of reactions. The second‐order rate constant of the reaction OIO + NO is determined to be (4.8 ± 0.9) × 10^?12 cm³ molecule^?1 s^?1 under 30 Torr of N₂ diluent at 298 K. We have also measured upper limits for the second‐order rate constants of OIO with NO₂ and Cl₂ to be k < 6 × 10^?14 cm³ molecule^?1 s^?1 and k < 8 × 10^?13 cm³ molecule^?1 s^?1, respectively. © 2007 Wiley Periodicals, Inc. Int J Chem Kinet 39: 688–693, 2007     

Anodic Stripping Voltammetric Determination of Mercury(II) in Water Using a 4‐Tert‐Butyl‐1‐(Ethoxycarbonylmethoxy)Thiacalix[4]Arene Modified Glassy Carbon Electrode

A glassy carbon electrode coated the film of 4‐tert‐butyl‐1‐(ethoxycarbonylmethoxy)thiacalix[4]arene is designed for the determination of trace amounts of Hg²⁺. Compared with bare glassy carbon electrode, the modified electrode can improve the measuring sensitivity of Hg²⁺. Under the optimum experimental condition, the modified electrode in 0.1 mol L^?1 H₂SO₄ + 0.01 mol L^?1 KCl solution shows a linear voltammetric response in the range of 8.0 × 10^?9 ～ 3.0 × 10^?6 mol L^?1 with detection limit 5.0 × 10^?9 mol L^?1 for Hg²⁺. The high sensitivity, selectivity, and stability of modified electrode also prove its practical application for a simple, rapid and economical determination of Hg²⁺ in water samples.     

CO2‐promoted Water‐medium Ullmann Reaction over a Pd/Phenyl‐SBA‐15 Mesoporous Catalyst

Water‐medium Ullmann reaction was carried out in CO₂ atmosphere over the mesoporous Pd/Ph‐SBA‐15 catalyst exhibiting high activity and selectivity owing to the uniform dispersion of Pd particles and hydrophobilic mesoporous channels which facilitate the diffusion and adsorption of organic molecules, especially in an aqueous medium. The CO₂ also shows promoting effect on activity and selectivity, which could be understood by considering the role of H⁺ in the mechanism of Ullmann reaction. The optimum Ph‐Ph yield (84.0%) was obtained at p=0.8 MPa and V=6.0 mL and could remain almost unchanged even after the catalyst has been used repetitively for 5 times.     

[Cu(L)](NO3)2 (L=4,7‐Bis(3‐aminopropyl)‐1‐thia‐4,7‐diazacyclononane) as a Suitable Ionophore for Construction of Thiocyanate‐Selective Electrodes and Their Use in Determination of Urinary and Salivary Thiocyanate Concentration

The construction, performance characteristics, and application of polymeric membrane (PME) and coated graphite (CGE) thiocyanate‐selective electrodes are reported. The electrodes were prepared by incorporating the complex [Cu(L)](NO₃)₂ (L=4,7‐bis(3‐aminopropyl)‐1‐thia‐4,7‐diazacyclononane) into a plasiticized poly(vinyl chloride) membrane. The influence of membrane composition, pH of test solution, and foreign ions were investigated. The electrodes reveal Nernstian behavior over a wide SCN^? ion concentration range (1.0×10^?6–1.0×10^?1 M for PME and 5.0×10^?7–1.0×10^?2 M for CGE) and show fast dynamic response times of 15 s and lower. The proposed sensors show high selectivity towards thiocyanate over several common organic and inorganic anions. They were successfully applied to the direct determination of thiocyanate in urine and saliva of smokers and nonsmokers, and as an indicator electrode in titration of Ag⁺ ions with thiocyanate.     

Highly Selective Perchlorate Membrane Electrode Based on Cobalt(III) Schiff Base as a Neutral Carrier

A highly selective poly(vinyl chloride) (PVC) membrane electrode based on Co(III)-Schiff base [Co(5-NO2- Salen)(PBu3)]ClO4•H2O (where 5-NO2-SalenH＝bis(5-nitrosalycilaldehyde)ethylenediamine) as a new carrier for construction of perchlorate-selective electrode by incorporating the membrane ingredients on the surface of a graphite electrodes has been reported. The proposed electrode possesses a very wide Nernestian potential linear range to perchlorate from 1.0×10－6 to 5.0×10－1 mol•L－1 with a slope of (59.4±0.9) mV per decade of perchlorate concentration with a low detection limit of 5.0×10－7 mol•L－1 and good perchlorate selectivity over the wide variety of other anions. The developed electrode has an especially fast response (＜5 s) and a wide pH independent range (3.0—12.0) in comparison with recent reported electrodes and can be used for at least 2 months without any considerable divergence in their potential response. This electrode was used for the determination of perchlorate in river water, drinking water, sludgy water and human urine with satisfactory results without complicated and time consuming pretreatment.     

Kinetic Studies on the Reaction of Sodium Hexacyanoferrate（ll） Complex with Peroxydisulfate Anion

The oxidation of Na₄Fe(CN)₆ complex by S₂O anion was found to follow an outer‐sphere electron transfer mechanism. We firstly carried out the reaction at pH=1. The specific rate constants of the reaction, k_ox, are (8.1±0.07)×10^?2 and (4.3±0.1)×10^?2 mol^?1·L·s^?1 at μ=1.0 mol·L^?1 NaClO₄, T=298 K for pH=1 (0.1 mol·L^?1 HCl0₄) and 8, respectively. The activation parameters, obtained by measuring the rate constants of oxidation 283–303 K, were ΔH^≠=(69.0±5.6) kJ·mol^?1, ΔS^≠=(?0.34±0.041)×10² J·mol^?1·K^?1 at pH=l and ΔH^≠=(41.3±5.5) kJ·mol^?1, ΔS^≠=(?1.27±0.33)×10² J·mol^?1·K^?1 at pH=8, respectively. The cyclic voltammetry of Fe(CN) shows that the oxidation is a one‐electron reversible redox process with E_1/2 values of 0.55 and 0.46 V vs. normal hydrogen electrode at μ=1.0 mol·L^?1 LiClO₄, for pH=1 and pH=8 (Tris). respectively. The kinetic results were discussed on the basis of Marcus theory.     

The first automated 470.59 MHz 19F NMR‐controlled titration: dissociation constants and ion‐specific chemical shifts of 2‐amino‐4‐fluoro 2‐methylpent‐4‐enoic acid

2‐Amino‐4‐fluoro‐2‐methylpent‐4‐enoic acid, obtained as a 1 : 1 salt with trifluoro‐acetic acid, was characterized by ¹H and ¹⁹F high‐resolution NMR spectroscopy. High‐precision potentiometry led to the dissociation constants pK = 1.879 and pK = 9.054. The first automated 470.59 MHz ¹⁹F NMR‐controlled titration yielded the dynamic chemical shift 〈δ_F〉 as a function of pcH or τ and the ion‐specific chemical shifts: δ_F(H₂L⁺) = ?94.81 ppm, δ_F(HL) = ?94.21 ppm, δ_F(L^?) = ?92.45 ppm. The deprotonation gradients were found to be Δ₁ = ?0.60 ppm and Δ₂ = ?1.76 ppm. Copyright © 2002 John Wiley & Sons, Ltd.