识别过渡金属离子的1,8-萘二甲酰亚胺多胺衍生物荧光传感器的研究

A series of fluorescent chemosensors 1-3 were synthesized to detect transition metal ions. At the room temperature, fluorescence intensities of these chemosensors in acetonitrile without transition metal ions were found to be very weak, due to the process of the e±cient intramolecular photoinduced electron transfer (PET). However, after addition of the transition metal ions, the chemosensor 1-3 exhibits obvious fluorescence enhancement. Moreover, the intensity of the fluorescence emission of chemosensors increases significantly in the presence of Zn2+ and Cd2+. The fluorescent chemosensors with different polyamine as receptors show diverse a±nity abilities to the transition metal ions and signal the receptor-metal ion interaction by the intensity change of fluorescence emission.     

金属离子水化学-溶胶凝胶法制备固体催化材料的化学基础

简要介绍了作为溶胶凝胶法制备固体催化材料的化学基础的金属离子水化学进展.     

负载型纳米二氧化钛对重金属离子吸附性能的研究

采用溶胶-凝胶法制备二氧化钛溶胶, 将其浸渍在硅胶上, 合成了负载型纳米二氧化钛材料, 以X射线衍射(XRD)、扫描电镜(SEM)等手段对其进行了表征. 以ICP-AES为检测手段, 系统地研究了负载型纳米TiO₂材料对重金属离子Cd^2＋, Cr^3＋, Cu^2＋和Mn^2＋的吸附性能. 结果表明, 在pH 8～9范围内, 所研究的重金属离子均可被定量富集, 吸附的金属离子可用0.5 mol/L的HNO₃完全解脱. 负载型纳米二氧化钛对Cd^2＋, Cr^3＋, Cu^2＋和Mn^2＋的静态吸附容量分别为8.3, 13.1, 12.6和5.1 mg/g, 与未负载的纳米二氧化钛相近. 将其应用于环境标准样品中Cd^2＋, Cr^3＋, Cu^2＋和Mn^2＋的分离富集与测定, 结果满意.     

金属离子掺杂的TiO2薄膜的制备及其光催化降解甲苯的性能

 采用溶胶-凝胶法制备了负载于铝板上掺杂金属离子的TiO2薄膜光催化剂,并通过空气中甲苯光催化降解实验评价了其光催化活性. 结果表明,Pt和Fe的掺杂对TiO2薄膜的光催化活性起促进作用,甲苯降解率分别提高了17%和6%; Ag的掺杂引起催化剂失活; Mn的掺杂未对TiO2薄膜的光催化活性起明显促进作用. XRD结果表明,掺杂金属离子前后TiO2均为锐钛矿相; TEM观察到薄膜催化剂微观结构为球形颗粒,粒径分布均匀,平均粒径为19 nm; 紫外漫反射光谱表明,Pt-TiO2薄膜催化剂的反射率几乎为0,表明其对光的吸收能力很强,因而Pt掺杂的TiO2薄膜光催化降解甲苯的活性最高.     

溶胶-凝胶法制备纳米二氧化钛颗粒的研究

本文采用钛酸丁脂等原料,利用sol-gel方法制备了TiO2纳米颗粒.研究了不同实验顺序(滴入方式)和工艺参数对制备效果的影响.通过实验和对TiO2纳米粉末的TEM分析,获得了粒度(30-40nm)比较均匀的球型TiO2纳米颗粒.     

针形颗粒二氧化钛纳米薄膜的制备

使用醋酸修饰的溶胶-凝胶法制备了一种由针形颗粒构成的二氧化钛纳米薄膜.研究发现,可以通过控制溶胶-凝胶过程的反应条件控制所制备的纳米薄膜的形貌.对这种形貌的形成机理进行了讨论.     

纳米二氧化钛的制备及其光催化性能

分别采用水热法和溶胶-凝胶法制备了TiO2纳米粉体;利用X射线衍射仪和扫描电镜分析了两种方法制备的TiO2粉体的形貌和晶体结构,并测定了纳米TiO2粉体对罗丹明B的光催化降解活性.结果表明:采用水热法制备的TiO2纳米粉体含有锐钛矿相和金红石相,粒径较小,大约为50nm,而且分散均匀,光催化性能良好;采用溶胶-凝胶法制备的TiO2粉体经过550℃煅烧后仍然为锐钛矿相,而且粒径较大,大约为80nm.     

纳米SnO的溶胶-凝胶法制备与电化学性能

以氯化亚锡、草酸和无水乙醇为原料，采用溶胶-凝胶法制备了纳米SnO粉末，并用热重-差热分析、X-射线衍射分析、透射电镜和扫描电镜等多种电化学方法对其进行了表征。结果表明，采用溶胶-凝胶法可以制备出粒度分布较集中，平均粒径在20 nm左右的纳米SnO粉末。该纳米SnO的可逆容量达到607 mAh·g^-1，经80次循环后平均每次循环的容量损失只有0.056%，说明纳米SnO是一种优秀的高容量锂离子电池负极材料。     

苝酰亚胺衍生物荧光探针的制备及对金属离子的识别

苝酰亚胺衍生物(perlenediimides derivatives,PDIs)作为一类性能优异的新型光电材料,由于其良好的光电性能和强的化学可修饰性,使其在荧光探针方面有着良好的应用前景。以提高苝酰亚胺衍生物溶解性能、改善选择性能为研究切入点,以四氯苝酐为原料,在主链引入供电子基吡啶-2-甲氨基,制备苝酰亚胺衍生物N,N-二(吡啶-2-甲基)-1,6,7,12-四氯-3,4:9,10-苝二酰亚胺(PTCDI-ABD),并对其与Pb~(2+)、Cu~(2+)、Mg~(2+)、Ni~(2+)、Zn~(2+)、K~+、Na~+等金属离子络合后的荧光性能进行详细研究,确定特征金属离子,准确实现金属离子识别。研究证明该化合物分子结构的优化增加了其在空气中的稳定性,与金属离子络合后(即使在较低浓度0.1×10~(-5) mol·L~(-1)),吸收光谱发生蓝移,随着时间的延长,Cu~(2+)的存在导致荧光淬灭。研究显示该化合物是一个很好的Cu~(2+)荧光探针,准确度高、灵敏度强、选择性好、操作简便,容易进行大规模生产和标准化控制。     

碳纳米管负载纳米TiO2复合材料的制备及其性能

采用溶胶-凝胶法, 以钛酸丁酯为原料, 将纳米TiO2负载在碳纳米管(CNTs)表面, 制备了CNT-TiO2光催化复合材料. 通过X射线衍射(XRD)、透射电子显微镜(TEM)等手段研究了复合颗粒的形态结构及包覆情况, 通过UV-Vis漫反射谱分析比较了纯TiO2和CNT-TiO2的吸光性能, 并研究了不同温度热处理的CNT-TiO2光催化剂在紫外光照射下对甲基橙光催化降解的性能. 结果表明, 纳米TiO2颗粒以锐钛矿相存在, 紧密地包附在碳纳米管的管壁上, CNT-TiO2在紫外-可见光波长范围内均有较好的吸光性能, 450 ℃热处理后的复合光催化剂CNT-TiO2比纯TiO2对甲基橙光降解有更高的光催化活性.     

Apparent Molar Volumes of Divalent Transition Metal Cations in Dimethyl Sulfoxide Solutions

Densities for DMSO solutions of divalent transition metal perchlorates are reported. The partial molar volumes of the hexakis-(DMSO) cations are derived and discussed in terms of variation within the series. The ligand-field effect on the partial molar volume and enthalpy of solvation is demonstrated.     

过渡金属离子对HPAsMoVO杂多酸的氧化性能的影响

用H2-TPR方法研究了过渡金属离子及其含量对杂多酸-HxPAs0.2Mo10VOy的氧化性能的影响,并在固定床反应器上考察了M0.2HxPAs0.2Mo10VOy(M=Fe3 、Co2 、N i2 和Cu2 )催化剂对异丁烷选择性氧化的催化性能.研究结果表明用过渡金属离子取代杂多酸中的质子,可以在较大程度上增强杂多酸的低温氧化能力,其中Fe3 对增强杂多酸的催化活性最为明显,而Cu2 却有利于提高目的产物甲基丙烯酸的选择性.     

Catalytic Behaviour of Transition Metal Cations In Electrosynthesis and Growth of Nanostructure Conducting Polypyrrole Films On/Between the Passive Cu Interdigital Electrodes: Application In Gas Sensors

The electrosynthesis of nanostructured polypyrrole (PPy) on copper interdigital electrodes (Cu‐IDEs) surfaces was performed by anodic oxidation of pyrrole in the presence of oxalic acid in aqueous solution (passivation technique) by potentiostatic method. Some divalent transition metal ions (Fe(II), Co(II), Ni(II), Cu(II), Zn(II)) as catalyst can be used to polymers growth on/between spacing between passive Cu‐IDEs by using potentiostatic technique. The morphology of the conducting films was examined by field emission scanning electron microscope, indicating a dependence of the film morphology to catalyst type. The PPy films on Cu‐IDEs were used to investigate the properties of the gas sensing ability.     

Study of the Complexation Behavior of Calixarene with Transition Metal Cations by UV—vis and Fluorescent Spectra

A new fluorescent compound based on calix[4] arene skeleton was synthesized.Its complexation ability with transition metal ions,such as Fe^3 ,Co^2 ,Ni^2 ,Cu^2 ,Zn^2 and Ag^ ,Was investigated by UV-vis and fluorescent spectra.     

疏水型SiO2光学增透膜的制备

以正硅酸乙酯（TEOS）为有机醇盐前驱体,采用溶胶-凝胶技术,通过酸/碱二步法控制实验条件,结合三甲基氯硅烷（TMCS）对胶粒表面的修饰过程,制备出结构可控的疏水型SiO2薄膜.采用椭偏仪、FTIR、接触角测试仪、SEM等对薄膜的折射率、红外特性、接触角以及表面形貌等进行了测量.研究结果表明,疏水型SiO2薄膜的折射率在1.33～1.18之间连续可调;SiO2胶粒表面的亲水性－OH中的H已部分被非活性－Si(CH3)3基团取代;接触角由表面未修饰膜的40°左右增加到表面修饰膜的120°左右.     

Preparation and Crystal Growth of Transition Metal Dichalcogenides

Dichalcogenides are known from almost all transition metals. The representatives of this class of compounds show a number of interesting physical and chemical properties depending on their constituent transition metal and crystal structure, which makes them interesting for basic studies and applications in high-end electronics, spintronics, optoelectronics, energy storage, flexible electronics, DNA sequencing and personalized medicine to this day. Many of these properties and effects can only be investigated on chemically and crystallographically pure samples - usually on single crystals. The vast majority of these compounds can be crystallized using chemical vapour transport. However crystallization from the melt is also possible in a considerable number of compounds, including the frequently used self-flux technique. For several compounds the crystallization from different solvents or solvent mixtures by means of solvothermal or hydrothermal synthesis is described.     

Thin Layer Chromatography of Purines on Silica Gel G Impregnated with Transition Metal Ions; Assay of Caffeine and Theophylline in Pharmaceutical Formulations

This study was undertaken to develop thin layers of silica gel G impregnated with transition metal ions for separation, identification and estimation of purines. The influence of transition metal ions and eluting solvents on chromatographic behaviour (hR_f) has been studied. The method was applied for qualitative analysis of purines in the mixtures and quantitative analysis of purine bases in the mixture as well as in pharmaceutical formulations. The results were compared statistically with those obtained by official methods. The method is simple, reproducible, and accurate within 1.3 ± 0.6%.     

Surface Modification of Porous Silica with Bi-thiophene Tripodal Ligand and Aplication to Adsorption of Toxic Metal Cations

The immobilization of a thiophene-based tripodal ligand, with a donor sulfur, on the surface of an epoxide group containing a silica gel phase for the synthesis of a newly functionalized material based on porous silica-bound bi-thiophene tripodal ligand (SGBT) is described. The modified silica surface was characterized by ¹³C NMR of a solid sample, elemental analysis, and infrared spectra. This new material was also studied and evaluated by determination of the surface area using the BET equation, the adsorption and desorption capability using the isotherm of nitrogen and BJH pore sizes, respectively. The target material exhibits good thermal stability as determined by thermogravimetry curves. The synthesized material was utilized in column and batch methods for adsorption of Hg²⁺, Cd²⁺, Pb²⁺, Cu²⁺, Zn²⁺, K⁺, Na⁺, and Li⁺, and the material exhibits an affinity only towards toxic heavy metals.     

高分散隔离活性位催化剂中过渡金属离子结构对丙烷选择氧化反应性能的影响

考察了碱金属K修饰的SiO2负载极低含量过渡金属的高分散隔离活性位系列催化剂(K-M/SiO2(n(K)∶n(M)∶n(Si)=10∶1∶1000),M=V,Cr,Mn,Fe,Co,Ni,Cu,Zn)的丙烷选择氧化催化性能,并运用UV-Raman和CO2-TPD等方法,对该系列催化剂进行了结构和物化性能表征,探讨了催化剂的表面离子结构与催化反应性能之间的关系。 发现钾修饰的SiO2负载过渡金属高分散隔离活性位催化剂上过渡金属离子的组态结构,对丙烷选择氧化反应性能有重要影响。相对稳定的全充满或无d电子的表面离子结构有利于选择氧化反应进行,而存在多种价态的相对不稳定的离子结构有利于深度氧化的进行。 这一离子结构与丙烷选择氧化催化性能的关系与前期乙烷选择氧化规律相似,进一步说明在高分散隔离活性位催化剂中,过渡金属离子的电子组态结构是影响低碳烷烃选择氧化反应性能的最重要因素。     

Theoretical Studies on the Interaction between Metal Cations and Cytosine, Guanine

1 INTRODUCTION The study on the interaction between metal cations and biomacromolecules is one of the important subjects of bioinorganic chemistry. As is well known, the metal ions play an important role in keeping the basic structures and realizing the normal functions of biomacromolecules like proteins, nucleic acid, and peptide hormone[1]. However, at present the interac- tion mechanism has not been understood yet. In recent years remarkable achievements have been obtained in this fie…