Oriented structure of octadecyl acridine orange intercalated in the monolayer and Langmuir–Blodgett film of octadecyl adenine‐thymine base pairs

The oriented structure of acridine orange (AO) in both monolayer and Langmuir–Blodgett (LB) film has been studied by optical waveguide (OWG) spectroscopy using polarized incident light. Mixed monolayer and LB films, consisting of octadecyl acridine orange (C₁₈‐AO) incorporated in stacked base pairs of octadecyl adenine (C₁₈‐Ade) and octadecyl thymine (C₁₈‐Thy), were prepared on a quartz waveguide. Absorption of transverse electric field (TE) polarized light was about twice that of transverse magnetic field (TM) polarized light. Both OWG spectra have λ_max at 500 nm, which is characteristic of monomeric AO molecules. This result strongly suggests that C₁₈‐AO molecules were dispersed uniformly in the mixed monolayer and were excited more effectively by the TE polarized light. Since the absorption moment of AO molecules is related to their long axis, it is proposed that C₁₈‐AO molecules are incorporated in C₁₈‐Ade/C₁₈‐Thy pairs with the long axis parallel to the layer surface. The absorbance at 500 nm was proportional to the number of layers on the waveguide. The dichroic ratio of the absorbance at 500 nm for TE polarized light to that for TM polarized light was constant regardless of the number of layers. The C₁₈‐AO molecules were uniformly incorporated in each layer with the long axis relatively parallel to the layer surface. Copyright © 2004 John Wiley & Sons, Ltd.     

偶氮苯自组装单分子膜中长程电子转移机理

利用自组装技术在金电极表面构造了具有不同前端健长度偶氮苯功能化的单分子膜体系：Au／S（CH2）nNHCO-N＝N-OCH2CH3（n＝2，3，4，6）．研究结果表明，仍氮苯到金电极的表现电子转移速率随它们之间的距离长度的增加而呈指数性的下降趋势．基于Marcus电子隧穿理论，得到了此自组装膜体系的长程电子隧穿系数ρ＝（1．35±0．2）／CH2在和可逆电活性分子自组装膜体系及理论计算相比较的基础上，从偶氮苯分子自组装膜结构与电子转移过程的关系角度对这一结果进行了分析和说明．     

卟啉类自组装膜在电分析化学中的应用

评述了卟啉及其金属配合物自组装膜在电分析化学领域的应用研究进展,并简要介绍了卟啉的结构及其金属配合物的特点。对卟啉类自组装膜在电分析化学领域内的应用作了展望。     

自组装膜上细胞色素c的电化学石英晶体微天平实时表征和定量检测

采用电化学石英晶体微天平(EQCM)实时表征和定量检测细胞色素c(Cytc).在压电石英晶振表面上自组装巯基十一酸(MUA)单层膜,以盐酸1-乙基-3-(3-二甲基氨基丙基)碳二亚胺(EDC)和N-羟基琥珀酰亚胺(NHS)活化羧基,将Cytc共价固化到电极表面.EQCM实时监测了MUA的自组装和Cytc的固化过程,测定了二者在电极表面的覆盖度和Cytc的固化量.结果表明,Cytc在0.03～3.00μmol/L浓度范围内呈线性变化,检测限可达到1.19×10^-9mol/L.     

新型偶氮苯硫醇衍生物自组装膜的制备与结构表征

Self Assembled Monolayers(SAMs) of a series of mercapto contained azobenzene derivatives with the structure of CnH2n+1AzoO(CH 2)mSH (where n =4,6,8,10,12; with m =3,5 respectively) were prepared and characterized. Wettability measurement of water on the SAMs demonstrates that molecular packing density in the monolayers increases while the alkyl chain in the molecules is lengthened. Both the n and m values have similar contribution to the wetting property of SAMs. The RA IR spectra reveal that the alkyl chains in the SAMs tilt away dramatically from the surface normal direction with the increase in their length. However, the orientation of azobenzene moiety is found to be influenced slightly by the alkyl chain length, which is due to the tenderness of the molecule.     

Supramolecular Assembly Formation in Monolayers of tert-Butyl Substituted Copper Phthalocyanine and Tetrabenzotriazaporphin

The effect is studied of the layer formation conditions on the molecular arrangement of copper tetra- tert-butyl phthalocyanine (CuPctBu₄) and copper tetra- tert-butyl tetrabenzotriazaporphin (CuThptBu₄) at the air–water interface. The decrease in initial surface concentration of these compounds is shown to affect the molecular orientation, as indicated by the increase in the area per molecule. The data are interpreted in terms of formation of CuPctBu₄ and CuThptBu₄ monolayers with a face-on molecular arrangement when the initial surface concentration is sufficiently small (N less than 1.6 × 10^–7 mole/m² for CuPctBu₄ and N less than 4 × 10^–7 mole/m² for CuThptBu₄) and changes in the molecular orientation to edge-on when the N values are higher. It is emphasized that the edge-on orientation on the water surface is not only a molecular but a collective property of the azaporphyrine supramolecular assembly.     

自组装膜研究进展及其在传感器技术中的应用

本文对自组装膜技术近年来的研究进展了综述。着重评述了在汞及金电极表面的含硫有机物所形成的自组装膜，并对其在传感器技术中的应用 进行了评价与展望。     

The study of preparation and luminescence of polymethyl methacrylate/rare earth composite luminescent materials

The alkaline-earth–rare-earth–aluminate systems phosphors are the new types of phosphors, which process very bright, safer, and excellent photoluminescence. Because of hydrolysis, however, the capacity of luminescent materials will fall down and the use value of luminescent materials will also be lost. Water-resistant polymers, which can form a kind of water-resistant clad on the surface of luminescent material powder, will solve this problem and the significance of its application is important. In this study, the polymethyl methacrylate (PMMA)/rare earth composite luminescent materials were prepared through grafting emulsion polymerization of methyl methacrylate onto the surface of luminescent materials. To study the structure and properties of the PMMA/rare earth composite luminescent materials, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and photoluminescent properties were measured. From the curves of FTIR and TGA, we can find that the organic parts are attached with the inorganic parts in the PMMA/rare earth composite luminescent materials. The results of luminescent decay curves show that the resistance to water of the PMMA/rare earth composite luminescent materials is much better than that of the unmodified luminescent materials because the organic parts had been grafted on the luminescent materials.     

Synthesis and infrared and fluorescence spectra of rare earth complexes with a novel amide-based ligand

A novel amide-based open-chain crown ether, N,N'-1,3-propanediyl-bis[2-(benzyl -carbamoyl-methoxy)-benzamide] (L) and its solid complexes with rare earth nitrates and picrates have been prepared. The complexes were characterized by elemental analyses, molar conductivity and IR spectra. The fluorescence properties of the Eu(III) and Tb(III) complexes in solid and in organic solvents were studied. Under the excitation of ultraviolet light, these complexes exhibit characteristic emission of europium and terbium ions. The results show that the ligand favor energy transfers to the emitting energy level of Tb(III). Some factors that influence the fluorescent intensity were also discussed.     

珍珠中痕量稀土元素的ICP-MS测定及其分布特性

探讨了等离子体质谱(ICP-MS)分析珍珠样品中稀土元素的基体效应及多原子离子干扰,并采用干扰校正因子进行有效的校正,以In-Rh双内标校正体系进行分析信号动态漂移的监控和补偿,建立了珍珠样品中稀土元素的ICP-MS分析方法。方法的定量检出限为0．1～0．5ng／g,RSD≤15％(n=5)。所建立的方法用于标准物质Gui-1、Gui-2、Gui-3及人工养殖珍珠的分析。珍珠中稀土元素的分布与分馏特性与其生长环境密切相关。     

基于纳米金自组装膜固定辣根过氧化物酶的生物传感研究

将辣根过氧化物酶(HRP)通过纳米技术和自组装技术固定于电极表面,制得了酶修饰电极.纳米金与HRP形成了静电复合物并高效地保持了HRP的生物活性,以对苯二酚作为电子媒介体,差示脉冲伏安法(DPV)研究生物酶电极测定H2O2的线性范围为5.0×10-6～1.0×10-3 mol/L,检测限为2.5×10-6 mol/L,线性方程为△I=0.34765+4.05553CH2O2(mM).酶电极的表观米氏常数(K(app))为0.0675 mmol/L.实验同时证明该生物酶电极具有良好的稳定性和使用寿命.     

Highly ordered amphiphilic cyclopalladated arylimine self‐assembly films for catalyzing Heck and Suzuki coupling reactions

A series of new cyclopalladated arylimine compounds ( 3a , 3b , 3c , 4a , 4b , 4c ) were synthesized and characterized. Their catalytic properties for Heck and Suzuki coupling reactions in a homogeneous system were preliminarily investigated using water as solvent, in which no ligands, air isolation or assistant solvents were needed in cross‐coupling reactions. The optimization of the homogeneous system provided a basis for research on the heterogeneous catalytic reaction catalyzed by ordered self‐assembly films. Organized monolayers of 3a , 3b , 3c were prepared and utilized as C? C coupling catalysts. Monolayers of 3a , 3b , 3c were deposited using Langmuir–Blodgett techniques and analyzed using π–A isotherms, UV–visible and X‐ray photoelectron spectroscopies and atomic force microscopy, which showed near orientation on the surface and stability under the optimized experimental conditions suitable for exploring Heck and Suzuki coupling reactions. The activity of immobilized 3c monolayer is enhanced relative to homogeneous reaction, in which the ordered monolayers are efficient with a catalyst loading as low as 10^?5 mol%, turnover number as high as 79 200 and turnover frequency as high as 2640 h^?1. The catalytic efficiency is 100 times higher than that in the homogeneous case using the same amount and ratio of reagent. The increased activity of immobilized 3c monolayer is due to a combination of its structure and changes in conformation when deposited onto the substrate. The topographic changes of catalyst films, stability of films and catalytic activity were investigated with atomic force microscopy, cyclic voltammetry, X‐ray photoelectron spectroscopy and inductively coupled plasma atomic emission spectrometry, from which a heterogeneous catalytic mechanism for Suzuki coupling reaction is proposed. The study demonstrates that careful monolayer studies can provide useful models for the design and study of supported molecular catalyst systems. Copyright © 2016 John Wiley & Sons, Ltd.     

Synthesis and fluorescence properties of rare earth (Eu3+ and Gd3+) complexes with alpha-naphthylacetic acid and 1,10-phenanthroline

Rare earth binary complex Eu(NNA)3 (NNA, alpha-naphthylacetic acid), ternary complex Eu(NNA)3.phen (phen, 1,10-phenanthroline) and a series of dinuclear complexes with different mole ratios of Eu3+ to Gd3+ were synthesized. Many advanced approaches, such as element analysis, FTIR spectra, TG and DTA analysis, were used to determine the composition and structure of binary and ternary complex. Moreover, their fluorescence properties were studied by fluorescent spectra and lifetimes. The fluorescence spectra and decay curves of dinuclear complexes indicated that the fluorescence emission intensity was enhanced and the fluorescence lifetime was prolonged by Gd3+. The dinuclear complexes show the best properties when the mole ratio of Eu3+ to Gd3+ is 6:4. A new parameter Y, which was used to evaluate the effect of Gd3+, was introduced. In addition, the relationship of Y value and mole fraction of Gd3+ was analyzed by mathematical software. The results showed that Y value decreased by single exponential mode when the content of Gd3+ decreased.     

偶氮苯衍生物自组装膜的表征及组装动力学

报导了4-正辛基-4′-（3－巯基丙氧基）偶氮苯（简称C8AzoC3）自组装膜（Self-AssembledMonolnyersSAMs）的表征及其自组装成膜动力学，接触角滴定、原子力显微镜（AFM）及电化学的实验结果表明，C8AzoC3分子在金表面自组装形成致密有序的流水性单分子膜，并且在电极上没有明显的电化学响应．通过控制组装时间，考察了偶氮苯自组装形成单分子膜的动力学过程，从接触角和电化学数据得到组装过程的速率常数kad为（1.2±0.2）×103mol-1·dm3·s－1；依据不同组装时间形成的自组装膜的特征循环伏安行为，提出了C8AzoC3分子在金表面自组装过程的动态模型．     

银菊珍珠胶囊中稀土元素的电感耦合等离子体质谱分析

建立了一种电感耦合等离子体质谱法测定银菊珍珠胶囊中稀土元素的方法。利用该方法分析了国家一级灌木枝叶标准物质（GBW 07603）和国际柑橘叶标准物质（NIST1572）中的稀土元素,结果与标准值一致。该方法已被用于分析银菊珍珠肢囊样品中的稀土元素。     

O-羧甲基壳聚糖稀土配合物的制备及与牛血清白蛋白的作用

合成了O-羧甲基壳聚糖与稀土La(Ⅲ)、Nd(Ⅲ)的配合物,并研究了与牛血清白蛋白(BSA)的相互作用。BSA紫外吸收光谱随配合物浓度的增加而表现出明显的减色效应和较小的蓝移;配合物对BSA的荧光具有较强的猝灭作用。     

Au(111)上烷烃硫醇SAMs表面应力的理论研究

By using the established statistical thermodynamic theory of adsorbate-induced surface stress of adsorption monolayer on the metal surface, the surface stress Δgin the self-assembly of alkane thiolson Au (111) surface has been calculated. The quantitative relations of the surfaces tress Δgwith the length of the alkyl chain of the molecule and with the coverage θ of molecules on Au (111) have been theoretically Studied respectively. The calculated results agree with Bergeretalis experiment, and especially the quantitative discrepancy between the theory and experiment on the sign of the surface stress has been resolved.Among various components of the adsorbate-adsorbate interaction energies in the ad layer, the substrate mediated interaction is significant for the adsorbate-induced surface stress, which shows that the indirect contribution of the adsorption energy of alkane thiols through the substrate-mediated interaction is very important.This physical mechanism is similar to that for chloride monolayer on the Au (111) electrode.     

氟化络合-ICP-MS法测定稀土金属中的难熔金属杂质元素Ta、Mo、W、Ti、Nb

针对稀土金属中难熔金属杂质元素Ta、Mo、W、Ti、Nb在HCl或HNO3中不易溶解的性质,本文在前人工作基础上,采用HF络合-ICP-MS结合的方法,有效地将上述元素溶解在溶液中,并利用ICP-MS高灵敏度和多元素同时测定的优势,成功建立了稀土金属中难熔金属杂质元素Ta、Mo、W、Ti、Nb的测定方法。其操作过程较传统化学方法简便,灵敏度也更高。本文分析了氢氟酸的络合过程,试验了稀土氟化物沉淀对被测元素的吸附作用和内标法的校正作用。方法检出限在0.3～1.5ng／mL,测定下限0.0005％～0.0010％,回收率在89.2％～118.9％,相对标准偏差为4.6％～9.7％。     

Synthesis of the rare earth compound nanosheets induced by lamellar liquid crystal

Synthesis of rare earth compound nanosheets with uniform thickness is of potential interest to the luminescent materials. Herein, whole series of rare earth hydrates and oxides nanosheets have been synthesized by using lamellar liquid crystal as a template, except Ce and Pm. Polarizing microscope images and transmission electron microscopy images show that the lamellar liquid crystal can prevent the rare earth hydrate nanosheets from curving to nanotubes in the processes of synthesis. The synthesized nanosheets have a uniform thickness of 10–15 nm and can retain morphology after being calcined at 650 °C. After facile chemical treatment, the functionalized rare earth compounds were obtained, which have unique luminescent property.     

1,3-Bis(alkylimino)isoindolinates of rare earth metals: Synthesis,molecular structure and photoluminescence

The rare earth metal isoindolinates Ln(ⁱPrL)₃ (Ln = Sc (1), Y (2), Eu (3), Dy (4), Yb (5); ⁱPrL = 1,3-bis(isopropylimino)isoindolinate anion) and [(MeL)Ce]₂(μ-MeL)₄ (6) (MeL = 1,3-bis(methylimino)isoindolinate anion) were synthesized by reactions of the amides Ln[N(SiMe₃)₂]₃ with 1,3-bis(isopropylimino)isoindoline (ⁱPrLH) or 1,3-bis(methylimino)isoindoline (MeLH), respectively. The X-ray diffraction study revealed that in monomeric molecules of the isopropyl-substituted compounds 2 and 4 the cations Ln³⁺ are η²-coordinated by three isoindolinate ligands. The methyl-substituted 6 exists in a crystal as a dimer containing two terminal η²-coordinated ligands and four bridging isoindolinate ligands two of which are bonded to Ce atoms in η³ fashion (η:η:η-N,N,N) but two others in η⁴ manner (η:η²:η-N,N,N). All the obtained complexes in solutions exhibited ligand-centered photoluminescence, the spectra of which consist of one broadened band with a maximum at 400–450 nm.