四(十六烷硫基)四硫富瓦烯/硬脂酸混合LB膜的结构研究

我们考察了四(十六烷硫基)四硫富瓦烯/硬脂酸(THT-TTF:SA=1:n)在气-液界面的聚集状态及在LB膜中的排列,当n=1时,THT-TTF分子在气-液界面形成了双分子膜;当n>6时,THT-TTF分子形成了单分子膜;1相似文献   

四(十六烷硫基)四硫富瓦烯/硬脂酸混合LB膜的结构研究

我们考察了四(十六烷硫基)四硫富瓦烯/硬脂酸(THT-TTF:SA=1:n)在气一液界面的聚集状态及在LB膜中的排列.当n=1时,THT-TTF分子在气-液界面形成了双分子膜;当n>6时,THT-TTF分子形成了单分子膜;1相似文献   

四硫富瓦烯衍生物/硬脂酸LB膜的导电性研究

报导了14种四硫富瓦烯衍生物／硬脂酸LB膜的导电性，并解释了硬脂酸量和碘蒸气掺杂对LB膜导电性的影响．     

不对称四硫富瓦烯衍生物合成新方法及其电化学性质的研究

以2,3－二（2′－氰乙硫基）－6,7－亚烷硫基四硫富瓦烯为原料,在醇钠的作用下消去氰乙基生成的二元硫负离子与对－二（氯甲基）苯反应除了生成两种新的不对称四硫富瓦烯衍生物外,还得到两种新的“二桥”－双四硫富瓦烯衍生物,为四硫富瓦烯衍生物的合成提供了一种新的方法。并对不对称四硫富瓦烯衍生物和“二桥”－双四硫富瓦烯衍生物的循环伏安图、电化学性质和UV－Vis光谱进行了研究。     

非两亲性四硫代富瓦烯导电LB膜的研究

近年来，利用LB技术制备电活性的有机超薄膜受到广泛的关注．导电LB膜的膜材料主要是含有受体化合物7，7’，8，8’-四氰基二亚甲基苯醌（TCNQ）的电荷转移复合物[1~3]以及给体分子[4，5]，特别是四硫代富瓦烯（TTF）衍生物[6~8]．尽管LB膜多由带长链的两亲性分子组装而成，但是对非两亲性TTF衍生物LB膜的研究[9~11]结果表明，引入长链烷基并非制备TTF类电荷转移复合物LB膜的先决条件．该结果极大地拓展了LB膜材料的研究范围．本文报道非两亲性TTF衍生物与花生酸混合导电LB膜的制备、结构表征与导电性能研究．1实验部分利用亚磷…     

四硫富瓦烯和蒽单元构建的新型多功能四硫富瓦烯环蕃的合成与性质

2,6-二(甲硫基)-3,7-二(2-氰乙基硫基)四硫富瓦烯在甲醇钠的作用下消除保护基团, 生成四硫富瓦烯双钠盐, 再与9,10-二(氯甲基)蒽反应生成由四硫富瓦烯(TTF)和蒽单元构建的新型TTF环蕃. 分别通过循环伏安法和化学氧化法对其电化学性质、紫外吸收光谱和荧光性质进行了研究, 实验结果表明此类TTF环蕃化合物对OH^－离子有识别功能. 并通过电化学和紫外吸收光谱研究了这种新型四硫富瓦烯环蕃在金纳米颗粒表面自组装行为.     

两个四硫富瓦烯分子正离子自由基TTF·^＋之间的共价吸引作用

使用MP2／6-311G方法得到了四硫富瓦烯自由基正离子二聚体（TTF·^＋ -TTF·^＋）能量极小点的结构．这显示这种正离子间的吸引作用存在．这种新的吸引作用是望远镜形状的20中心2电子分子间共价π/π键．这种共价π/π键的键能约为-21kcal·mol^-1,它被正离子间的库伦排斥作用掩盖．有负离子围绕的四硫富瓦烯自由基正离子二聚体（TTF·^＋ -TTF·^＋）体系是稳定的．     

基于四硫富瓦烯衍生物Langmuir-Blodgett膜的研究进展

在简要介绍了Langmuir-Blodgett (LB)膜的基础上, 主要依据制备LB膜的四硫富瓦烯(TTF)衍生物化学结构的不同, 概括了基于两亲性TTF衍生物、非两亲性TTF衍生物、TTF电荷转移(CT)复合物或盐、以及TTF金属络合物LB膜的制备、结构表征与性能研究进展. 介绍了基于TTF衍生物的LB膜在导电、化学及生物传感器、光学以及磁性方面的应用, 并对基于TTF衍生物LB膜的发展进行了展望.     

烷硫基甲硫富瓦烯的合成及其性质的研究

分别以1,3,4,6－四硫代戊搭烯－2,5－二酮和4,5－二（2′-氰基乙硫基）－1,3－二硫杂环戊烯－2－酮为原料,经偶联、醇解、烃化制得四甲硫基甲硫富瓦烯和四乙硫基四硫富瓦烯。对两种方法制得产物的产率存在较大差别提出了合理的解释,并讨论了2种四硫富瓦烯衍生物的循环伏安图及有关电化学性质。     

基于四硫富瓦烯衍生物导电LB膜研究概况

四硫富瓦烯(TTF)是具有可逆氧化还原性质的强电子给体, 由其衍生物制备的导电Langmuir-Blodgett (LB)膜可应用于分子材料及分子电子器件方面的研究. 简要综述了近年来具有代表性的基于TTF衍生物的导电LB膜及其可能用途.     

Microstructure and Ion Exchange in Stearic Acid Langmuir-Blodgett Films Studied by Fourier Transform Infrared-Attenuated Total Reflection Spectroscopy

Fourier transform infrared-attenuated total reflection (FTIR-ATR) spectra have been recorded of 11-layer Langmuir-Blodgett (LB) films of stearic acid deposited at various surface pressures (0.1, 15, and 35 mN/m), and the molecular orientation angles were evaluated quantitatively, which supplied insight into the molecular order with the alkyl chains tightly packed like crystal in the LB films deposited at the zero and higher surface pressures. These experimental results indicate that, in the Langmuir film as the precursor of LB films, stearic acid molecules self-aggregate to form two-dimensional crystalline domains already even at the zero surface pressure, which results in the inhomogeneity of monolayer. The analysis of dependence of nu(C=O) intensity on the surface pressure, surface density, and subphase temperature leads to the conclusion that the defects in LB films originate from the Langmuir film and be conserved upon deposition. Annealing below 50 degrees C and cooling could improve the monolayer homogeneity, and thus a defect-free or low-defect LB films can be deposited. Furthermore, ion exchange conducted in the LB films, on the other hand, confirms the existence of structure defects in LB films of stearic acid. The polar plane microstructure, lateral transport along the polar planes and the coordination types of stearic acid/cation system may be the rate-limiting process. The results have implication on the possible uses of stearic acid LB films as ion-exchange materials or sensors. Copyright 2001 Academic Press.     

Cd2+-induced interfacial structural changes of Langmuir-Blodgett films of stearic acid on solid substrates: a sum frequency generation study

The molecular structures and their stabilities at the outmost-layer of the Langmuir-Blodgett (LB) films of stearic acid on solid substrates have been investigated by a highly surface-sensitive spectroscopic technique, sum frequency generation (SFG), in air and in aqueous solution, using the combination of both normal and deuterated stearic acid. Peaks observed in the SFG spectra are mainly attributed to the terminal methyl group at the outmost layer of the LB films. The SFG spectra in air are virtually identical and are independent of the odd-even property and thickness (1-12) of the LB films, indicating that the even-numbered LB film changes its surface structure after passing through the interface between the water subphase and air, especially when the Cd2+ cation was included in the water subphase. Furthermore, we have demonstrated for the first time using in situ SFG measurement that the interfacial molecular structure at the LB bilayer of stearic acid on the hydrophilic substrates significantly change with immersion in the water subphase containing Cd2+ cation while such a structural change has not been observed in the water subphase without Cd2+. These results clearly indicate that a reorganization process takes place on the surface of the stearic acid bilayer induced by the Cd2+ cation. The electrostatic interaction between the carboxylate headgroup of stearic acid via the Cd2+ cation seems to play an important role in the surface reorganization process both in air and in solution.     

Effect of thickness and monolayer location on thermostability of metal stearate LB films studied by FT-IR reflection—absorption spectroscopy

LB films of Cd and Ca stearates with 1, 3, 9, and 21 monolayers were fabricated on silver-coated glass slides. 9-Monolayer LB films of Cd and Ca salts of deuterated stearic acid, in which the 1st, 5th, or 9th layer was replaced by 1 monolayer of undeuterated analogues, were also prepared on the above substrates. Temperature dependences of Fourier transform infrared (FT-IR) reflection—absorption (RA) spectra were examined for these LB films in the range 31–140°C. At room temperature, the hydrocarbon chains in these LB films were in a well-ordered state with a high degree of perpendicular orientation to the substrate. However, they became disordered at elevated temperatures. These order-disorder phase transition temperatures were dependent on the film thickness, to a small degree in the Cd stearate LB film (102–108°C), but to a large degree in the Ca stearate LB film (103–129°C). In the latter LB film, the effect of dehydration was inferred. The degree of disorder at high temperatures was dependent on the film thickness and the location of monolayer in the 9-monolayer LB films. This result is discussed in terms of the internal pressure within the LB film.     

Role of microenvironment in the mixed Langmuir-Blodgett films

This paper reports the pi-A isotherms and spectroscopic characteristics of mixed Langmuir and Langmuir-Blodgett (LB) films of nonamphiphilic carbazole (CA) molecules mixed with polymethyl methacrylate (PMMA) and stearic acid (SA). pi-A isotherm studies of mixed monolayer as well as the remarkable change in collapse pressure of the mixed monolayer isotherms definitely show that CA is incorporated into PMMA and SA matrices. However, CA is stacked in the PMMA/SA chains and forms microcrystalline aggregates, as is evidenced from the scanning electron micrograph picture. The nature of these aggregated species in the mixed LB films has been revealed by UV-vis absorption and fluorescence spectroscopic studies. The presence of two different kinds of band systems in the fluorescence spectra of the mixed LB films have been observed. This may be due to the formation of low-dimensional aggregates in the mixed LB films. Intensity distribution of different band systems is highly sensitive to the microenvironment of two different matrices as well as also on the film thickness.     

10,12—双炔廿三酸盐的LB膜特性研究

本文合成了10,12-双炔廿三酸,并用其在Si、SiO_2、CaF_2等基片上沉积了LB膜,结果表明,10,12-双炔廿三酸的镉盐成膜更稳定。这种LB膜在紫外光辐照下很快聚合,聚合前后的紫外-可见吸收光谱发生规律性的变化,并保持层状结构,等同周期稍变。通过红外吸收的二向色性分析,确定了该分子的取向。     

Immbolization of uricase enzyme in Langmuir and Langmuir-Blodgett films of fatty acids: possible use as a uric acid sensor

Preserving the enzyme structure in solid films is key for producing various bioelectronic devices, including biosensors, which has normally been performed with nanostructured films that allow for control of molecular architectures. In this paper, we investigate the adsorption of uricase onto Langmuir monolayers of stearic acid (SA), and their transfer to solid supports as Langmuir-Blodgett (LB) films. Structuring of the enzyme in β-sheets was preserved in the form of 1-layer LB film, which was corroborated with a higher catalytic activity than for other uricase-containing LB film architectures where the β-sheets structuring was not preserved. The optimized architecture was also used to detect uric acid within a range covering typical concentrations in the human blood. The approach presented here not only allows for an optimized catalytic activity toward uric acid but also permits one to explain why some film architectures exhibit a superior performance.     

稀土三酞菁夹心化合物混合LB膜的研究

将不对称三明治型夹心化合物(Pc)Dy[Pc(OC₈H₁₇)₈]Dy[Pc(OC₈H₁₇)₈]与硬脂酸混合成膜，表面压-面积（π-A）曲线表明形成了稳定的单层膜，由透射电子显微镜（TEM）观察,表明硬脂酸的加入有效地改善了分子的聚集行为，分子形成了取向高度有序的结构。用紫外-可见光谱、偏振紫外可见光谱、低角X射线衍射等对LB膜进行了研究，发现该取代稀土三酞菁分子在气/液界面上长链向上伸展，分子之间均以面对面（face-to-face）排列，以一边接触（edge-on）方式取向,大环平面与基片夹角约为52°，每层厚度为2.41 nm。     

镶嵌血卟啉的硬脂酸LB膜研究

制备了嵌有血卟啉的硬脂酸LB膜, 结果表明, 血卟啉分子镶嵌在硬脂酸间分子膜内, 在混合LB膜中血卟啉分子之间未发生强的相互作用, 其大环平面为倾斜取向。     

血红素在有序分子膜中的行为研究

本文研究了血红素(Heme)在硬脂酸(SA)单分子膜和Langmuir-B1odgett(LB)膜中的行为。Heme及其与SA的混合物均能在纯水亚相形成稳定的单分子膜。当摩尔分数x