Novel Hydrazone‐Based Tripodal Sensors: Single Selective Colorimetric Chemosensor for Acetate in Aqueous Solution

A series of novel tripodal colorimetric anion sensors based on hydrazone CHN NH groups have been synthesized and their recognition behavior with anionic guests has been studied. In DMSO solutions, sensors 1 and 2 show colorimetric responses for F⁻, H₂PO⁻₄ and AcO⁻, while in DMSO/H₂O (9:1, V/V) solutions, sensor 1 shows single selectivity for AcO⁻. ¹H NMR titration confirms that the tripodal sensors could bind anions through the collaboration of three hydrazone groups and anions residing in the central cavity of the sensors.     

基于酰腙和酚羟基的阴离子受体的合成及其在含水介质中的阴离子比色识别性能

设计合成了一系列基于羟基和氨基的酰腙类受体分子.利用紫外-可见吸收光谱及1HNMR考察了其与F-,Cl-,Br-,I-,CH3COO-,H2PO4?,HSO4?,ClO?4等阴离子的作用.结果表明,该类受体分子在DMSO溶液中能较好地比色识别F-,CH3COO-,H2PO4?,其中受体2在含水介质中[V(DMSO)∶V(H2O)=7∶3]能选择性比色识别CH3COO-.1HNMR滴定实验研究了受体分子与阴离子之间的作用,结果表明受体分子与阴离子之间以氢键作用方式相结合.     

IrO2电极在4-氯苯酚水溶液中的电化学活性

研究了在4-氯苯酚(简称氯酚)电化学稳定窗口内氯酚对Ti基IrO2电极在酸性水溶液中电化学活性的影响. 循环伏安(CV)与电化学阻抗谱(EIS)测试均显示, 几乎在整个氯酚的电化学稳定电位区间内, 氯酚对氧化物电极均起到活化作用. 以金属Ir电极为对比试样的测试结果却显示, 由于氯酚易于在金属表面吸附, 氯酚在其电化学稳定窗口内对金属电极的活性产生抑制作用. 基于氯酚对上述两类电极电化学行为影响的差异, 提出活性氧化物自身在上述电位区间内发生从低价态到高价态的转变, 进而用于氧化去除吸附在电极表面的有机分子, 可能是氯酚对IrO2电极造成活化的主要原因.     

N2,O2水溶液光谱的分子动力学模拟

用分子动力学模拟方法研究了N2和O2水溶液的光谱性质．给出了能描述分子内部运动的溶质－溶剂相互作用势．对溶质和溶剂原子的速度自相关函数（VACF）作了计算．讨论了所得VACF的性质并计算了其谱密度．溶质分子振动谱出现的红移，与液态N2，O2的Raman实验结果相吻合．模拟得出的转动谱表明了溶剂分子对溶质转动运动的阻滞，模拟结果也表明VACF计算对溶液和液体光谱的研究十分有效．     

功能化纳米金比色检测水中Cr~(3+)

采用柠檬酸钠还原法制备粒径13 nm的金纳米颗粒(AuNPs)作为比色信号报告分子,3-氨基-5-巯基-1,2,4-三唑(AMT)作为Cr~(3+)的识别分子,构建了一种水中Cr~(3+)的比色传感检测方法。将AMT修饰于AuNPs表面,形成稳定的AMT-AuNPs水溶复合物;根据AMT与Cr~(3+)之间的特异性结合,引起溶液中AMT-AuNPs聚集,进而导致溶液颜色由红色变为蓝紫色以及最大吸收峰红移的现象,实现了水中Cr~(3+)的比色检测。在优化实验条件(AMT修饰浓度为0.8μmol/L,pH 7.0)下,该方法的检测范围为6~14μmol/L,检出限可达100 nmol/L,其他重金属离子几乎不存在干扰。由于该方法具有响应快(5 min)、制备和操作简单、无需读取装置等优点,可望用于水体中Cr~(3+)的现场快速检测。     

Novel N,N＇-Diacylhydrazine-Based Colorimetric Receptors for Selective Sensing of Fluoride and Acetate Anions

Three novel and simple N,N＇-diacylhydrazine-based colorimetric receptors have been prepared. The binding properties of the receptors to anions such as F^-, Cl^-, Br^-, AcO^-, HSO4^- and HEPO4^- in acetonitrile solution were examined by UV-Vis spectroscopy methods, which show high sensitivity and selectivity to F^- and AcO^- over other anions. The results indicated that a 1 ： 1 stoichiometry complex was formed between the receptors and the anions, while ^1H NMR titrations confirmed hydrogen binding interaction between the receptors and the anions.     

A Novel Chemical Sensor Based on Sb2S3 Film for Highly Sensitive Detection of Hydrazine

The Sb₂S₃ film on indium‐tin oxide (ITO) substrate has been used as an efficient electron transfer mediator for the fabrication of novel chemical sensor towards hydrazine, which is a diamine known as neurotoxin and carcinogen. Sb₂S₃ film is deposited on ITO substrate by drop‐casting process using Sb₂S₃ solution as precursor and possesses reticular structure with the morphology of uniform hollow hemispheres. The fabricated chemical sensor for selective detection of hydrazine displays a high sensitivity of 106.25 μA/(mM cm²) with a low detection limit of 0.5 μM and it also exhibits excellent reproducibility and stability in hydrazine detection.     

A Highly Selective and Sensitive Fluorescent Chemosensor for Detection of Al3+ in Totally Aqueous Media

A fluorescent chemosensor ( 1 ) based on 2‐hydroxy‐1‐naphthaldehyde Schiff‐base was developed for the detection of Al³⁺ in 100% aqueous solution. Upon addition of Al³⁺, a significant fluorescence enhancement was observed, which was not affected by other metal ions including Na⁺, K⁺, Ca²⁺, Mg²⁺, Mn²⁺, Co²⁺, Ni²⁺, Cu²⁺, Cr³⁺, Ag⁺, Pb²⁺, Zn²⁺, Cd²⁺, Hg²⁺, Fe²⁺ and Fe³⁺ under weak acid conditions. Moreover, the specific response to Al³⁺ was visible under natural light. The binding mode between 1 and Al³⁺ was clarified by ESI‐MS and ¹H NMR.     

基于偶氮水杨醛酰腙的氰根比色检测探针的合成及性能

设计合成了一种基于酚羟基和氨基的酰腙类探针分子, 利用紫外-可见吸收光谱和核磁滴定考察了其对F^-, Cl^-, Br^-, I^-, CH₃COO^-, H₂PO₄^-, HSO₄^-, ClO₄^-, CN^-, SCN^-, SO^2-₄和NO^-₃等阴离子的识别作用. 结果表明, 当加入CN^-离子时主体溶液颜色由无色变为黄色, 而加入其它离子时主体溶液颜色不变, 说明该探针在DMSO/H₂O(体积比5: 5)体系中能选择性裸眼比色检测CN^-. 核磁滴定及质谱数据表明, 该探针与CN^-以1:1化学计量比结合, 该过程通过亲核加成方式完成.     

LiV3O8在Li2SO4水溶液中的电化学性能

采用低温固相法合成了具有纳米结构的LiV₃O₈材料.扫描电子显微镜（SEM）及透射电子显微镜（TEM）测试显示该材料具有纳米结构.X射线衍射（XRD）表明该材料属于单斜晶系,P2₁Im空间群.并采用循环伏安法（CV）及电化学阻抗谱图测试对该材料在1、2 mol·L^-1Li₂SO₄水溶液及饱和Li₂SO₄水溶液中的电化学行为进行了研究.结果表明,LiV₃O₈在饱和Li₂SO₄水溶液中具有最好的电化学性能.以LiV₃O₈作为负极材料,LiNi_1/3Co_1/3Mn_1/3O₂作为正极材料,饱和Li₂SO₄水溶液作为电解液组成了水性锂离子电池,进行恒流充放电测试,结果表明,在0.5C(1C=300 mA·g^-1)的充放电倍率下,该水性锂离子电池的首次放电比容量为95.2 mAh·g^-1,循环100次后仍具有37.0 mAh·g^-1的放电比容量.     

DEA-CO2水溶液的表面张力研究

用全自动表面张力仪测定了293.15～323.15 K温度范围内,具有不同CO2载荷的二乙醇胺(Diethanolamine,DEA)水溶液的表面张力,提出了适宜表达DEA-CO2水溶液表面张力的热力学模型,计算结果与实验值吻合良好.在实验测定和理论计算的基础上,阐明了温度、DEA浓度和CO2载荷对DEA-CO2水溶液表面张力的影响规律.     

离子液体表面活性剂在水溶液中的自组装及其调控研究进展

离子液体表面活性剂在化学合成、材料制备和环境污染控制等方面的应用与它们在水溶液中的自组装及其微观结构密切相关。因此,研究离子液体表面活性剂在水溶液中的自组装行为具有重要的意义。本文重点综述了阳离子的结构、阴离子的类型、外加电解质、有机添加剂、环境因素(温度、溶液pH值和光)等对离子液体表面活性剂在水中的自组装行为以及对组装体结构影响的研究进展,总结了这些因素对离子液体表面活性剂在水中自组装的调控规律,展望了该领域的发展方向及面临的挑战。     

Novel Approach for the Decoration of Magnetic Carbon Nanospheres with Platinum Nanoparticles and Their Enhanced Peroxidase Activity for the Colorimetric Detection of H2O2

Pt/Fe3O4-DIB-DETA-CNS(PFDDC)nanocomposite(DIB=2,4-dihydroxybenzaldehyde;DETA=diethylenetfiamine;CNS=carbon nanosphere)was synthesized by dispersing Pt nanoparticles on magnetic carbon nanospheres. The structure,morphology and composition of the nanocomposite were studied by X-ray diffraction(XRD),transmission electron microscopy(TEM),energy-dispersive X-ray spectroscopy(EDX)and X-ray photoelectron spectroscopy(XPS). In addition,the nanocomposite showed superior peroxidase-like activity towards 3,3',5,5'-tetramethylbenzidine(TMB) with a visual color change in the presence of hydrogen peroxide(H2O2).Therefore,the PFDDC nanocomposite provides a sensing platform for the colorimetric detection of H2O2 with high sensitivity and selectivity.Furthermore,the nanocomposite can be conveniently preserved and separated.These features enable the nanocomposite to colorimetrically detect H2O2 for potential pharmaceutical,environmental and industrial applications.     

Effect of the Type of Glycosidic Linkage on the Selective Interactions of Maltose and Cellobiose with Some Crown Ethers in Dilute Aqueous Solutions

Titration calorimetric and densimetric measurements have been applied to study the selective interactions of two disaccharides composed of two glucose units, maltose and cellobiose, with 15-crown-5 and 18-crown-6 in dilute aqueous solutions. Maltose and cellobiose form thermodynamically stable complexes with different stoichiometries with 18-crown-6 but not with 15-crown-5. The obtained results are explained by the different states of the disaccharides in aqueous solution due to effect of the type of linkage between glucose units     

微量热法研究烟酰胺和异烟酰胺在KCl水溶液中的焓对自缔合作用

利用等温滴定微量热法(ITC)分别测定了298.15 K时烟酰胺(NA)和异烟酰胺(INA)在纯水及不同浓度KCl(m=0~0.3 mol/kg)水溶液中的稀释焓,根据McMillan-Mayer理论计算得到相应的焓对自缔合作用系数(h xx),发现两者的h xx都是很大的负值,且在较高KCl浓度时都随KCl浓度的增大而减小.从溶质-溶质、溶质-溶剂相互作用的观点出发,对这2种吡啶羧酸酰胺异构体的疏水和亲水作用平衡进行了讨论:NA和INA都是亲水-亲水作用占优势,芳香性的吡啶环与酰胺基团羰基的π电子共轭使得对位异构体的共振结构分子电荷分离而更具亲水性;吡啶环之间的π-π堆叠对焓对自缔合作用的贡献几乎可忽略;溶液离子强度(I)的增大有利于加强亲水-亲水作用,从而使h xx的绝对值都随溶液中KCl浓度的增大而逐渐增大.     

A Novel Method for the Rapid Determination of Isonicotinic Hydrazide in Aqueous Solutions Using Reflectance Spectrophotometry and Colorimetry

A rapid method is developed for the quantitative determination of 5–35 g/L of isonicotinic hydrazide (INH, isoniazide) in aqueous media. The method is based on the formation of copper(I) oxide in the reaction of isonicotinic hydrazide with copper ions on the surface of indicator tablets and the subsequent recording of the analytical signal by reflectance spectrophotometry and colorimetry. Aluminum oxide is proposed as a solid-phase substrate for the production of indicator tablets. Isonicotinic hydrazide can be determined in the tablet form of the Isoniazid preparation.     

第一性原理方法预测水相核酸碱基及其代谢物的氧化还原电动势

氧化还原电动势是了解核酸中电荷/电子转移过程以及设计具有新型氧化还原活性的碱基类化合物的重要参数. 本文对82个芳香化合物的氧化还原电动势进行理论预测, 通过计算值和实验值的比较发现: 气相采用B3LYP/6-311++G(2df,2p)//B3LYP/6-31+G(d)方法, 液相采用HF-COSMORS/UAHF方法, 对运用HF- CPCM/UAHF方法在水相重新优化的构型计算溶剂化能, 能有效预测芳香化合物水相氧化还原电动势, 该理论方法计算的绝对均方根误差(RMSD)为0.124 V. 运用该理论方法成功预测了属于芳香化合物的核酸碱基及其代谢物的水相氧化还原电动势. 根据预测结果, 讨论了核酸中电荷/电子转移过程以及结构改变对设计具有新型氧化还原活性的核酸碱基类化合物的影响. 本文为设计具有氧化还原活性的新型核酸碱基类化合物提供了一种理论方法.     

在电解质溶液中测定非电解质溶解度的新方法

提出了一种可以同时测定电解质溶液中非电解质的溶解度和饱和溶液水活度的新方法。该法把等压平衡与传统化学分析统一起来,其优点是：（1）将多元饱和溶液中非电解质溶解度的测定转变为共存离子的溶度测定,避开了对非电解质难于进行精确化学分析的难题;（2）可以同时确定所测饱和体系的水活度。用该法测定了NaCl和KCl溶液中甘露醇的溶解度并与文献值进行了比较,结果表明二者符合得很好。     

Rapid Automatic Determination of Calcium and Magnesium in Aqueous Solutions by FIA Using Potentiometric Detection

A pH‐sensitive detector for flow‐through potentiometry based on a graphite/quinhydrone/silicone composite electrode was applied to determine calcium and magnesium in aqueous solutions. The determinations are performed by FIA titrations with EDTA as the carrier solution. The method was applied to the analysis of mineral water, drinking water, and river water. The results were compared with those obtained by batch complexometric titration. The proposed new method is suitable for the simple, rapid and automated determination of water hardness in small sample volumes of aqueous solutions. The detection limit for both ions is about 1×10^?5 mol L^?1, the standard deviation is less than 2%. The sampling frequency is 60 determinations per hour.     

Preparation of Fluorescent Thiol Group‐Functionalized Silica Microspheres for the Detection and Removal of Silver Ions in Aqueous Solutions

We demonstrate that silica microspheres can act as a sensitive fluorescent sensor and adsorbent of Ag⁺ in aqueous media. These thiol‐functionalized silica microspheres are doped with quantum dots (QDs) using organosilane chemistry in a one‐step preparation. Ligand exchange takes place between the thiolated organosilane and acid‐capped QDs, making the doping easy. Ag⁺ adsorption by the silica microspheres causes the decrease of fluorescence intensity of the QDs. The detection limit for Ag⁺ is found to be 10 μmol/L. The abundance of thiol groups on the surface of the microspheres could effectively remove Ag⁺ through strong interaction. When microspheres with a diameter of 1.1 μm are used as the adsorbents, the adsorption capacity for Ag⁺ reached 102 mg/g. This excellent adsorption ability is due to the abundance of thiol groups that act as the active sites, facilitating the adsorption of the massive metal ions on the surface of the microspheres. Furthermore, the adsorption isotherm data follows the Freundlich model. The structure and content of the silica microspheres were investigated by scanning and high‐resolution transmission electron microscopy, energy dispersive X‐ray spectroscopy, and Raman analysis, and the fluorescence properties were characterized by fluorescence microscopy.