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首页> 外文学位 >Cyclodextrin complexation of several guests in water and water-urea mixtures and studies on the adsorption of organic molecules on bare and modified gold electrodes.
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Cyclodextrin complexation of several guests in water and water-urea mixtures and studies on the adsorption of organic molecules on bare and modified gold electrodes.

机译：几种客体在水和水-尿素混合物中的环糊精络合作用以及在裸露的和修饰的金电极上吸附有机分子的研究。

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摘要

The complexation of several alkyldimethyl(ferrocenylmethyl)ammonium cations by the hosts {dollar}alpha{dollar}- and {dollar}beta{dollar}-cyclodextrin was investigated in aqueous media using calorimetric and {dollar}sp1{dollar}H NMR spectroscopic measurements. The calorimetric results indicate that the complexation of all the ferrocene-containing guests is enthalpically driven.; The thermodynamic functions that describe the complexation of a series of four carboxylic acid guests and two related quaternary ammonium derivatives with {dollar}beta{dollar}-CD were measured using flow calorimetry at 298 K in aqueous media in the presence and in the absence of large concentrations of urea. The relative differences of the thermodynamic parameters of complexation revealed the existence of specific interactions between urea and the aromatic surfaces of some of the guests.; The adsorption of two viologen-containing polyelectrolytes on the surface of carboxylate-terminated, self-assembled monolayers was investigated by voltammetric methods. Both polyelectrolytes were found to adsorb on either Au/SC{dollar}sb2{dollar}COOH or Au/SC{dollar}sb7{dollar}COOH monolayers at neutral pH. However, the adsorption was optimized by using the more hydrophobic polyelectrolyte and the longer thiol.; Self-assembled aggregates of the three modified cyclodextrins (hexakis, heptakis and octakis(2,3-O-hexyl-6-deoxy-G-amino)-{dollar}alpha , beta{dollar} and {dollar}gamma{dollar}-CD) on bare gold, and on the modified gold substrates Au/SC{dollar}sb2{dollar}COOH and Au/SC{dollar}sb7{dollar}COOH, were investigated by cyclic voltammetric, contact angle, FT-IR and quartz crystal microbalance measurements in neutral aqueous media. The level of organization of the CD derivatives on the negatively charged surface of the modified gold electrodes, proved to be substantially better than that on bare gold electrodes. Exposure of the CD-modified electrodes to solutions containing micromolar levels of ferrocene showed that binding of the organic substrate took place inside the hydrophobic aggregates.; The binding constants for hexafluorophosphate, perchlorate and triflate with {dollar}alpha{dollar}- and {dollar}beta{dollar}-cyclodextrins were studied using calorimetry, fluorescence spectroscopy and molecular orbital calculations. In particular, the binding constant of hexafluorophosphate and {dollar}beta{dollar}-cyclodextrin was measured to be ten times larger than the previously reported value.; The complexation of phosphate ion by {dollar}beta{dollar}-amino-cyclodextrin was detected by voltammetric methods through the competitive displacement of ferrocene methanol and ferrocenecarboxylate in neutral aqueous media. Using the RDV technique and a commercial simulation software, the stability constants between {dollar}beta{dollar}-amino-CD and the three guests were determined.
机译：在水介质中，使用量热法和{sp1 {dollar} H} NMR光谱研究了主体{dollar}α{dollar}-和{dollar}β{dollar}-环糊精与几种烷基二甲基（二茂铁基甲基）铵阳离子的络合。量热结果表明，所有含二茂铁的客体的络合都是由焓驱动的。用流热量计在298 K的存在和不存在下，在含水介质中用量热法测定了描述一系列四个羧酸客体和两个相关季铵衍生物与{美元}β{美元}-CD的配合的热力学函数。高浓度的尿素。络合热力学参数的相对差异表明尿素与某些客体芳族表面之间存在特定的相互作用。通过伏安法研究了两种含紫精的聚电解质在羧酸酯封端的自组装单分子层表面的吸附。发现两种聚电解质在中性pH下均吸附在Au / SC {sb2 {dollar} COOH或Au / SC {sb7slb7 {dollar}} COOH单层上。然而，通过使用更多的疏水性聚电解质和更长的硫醇来优化吸附。三种修饰的环糊精（己基，庚基和辛基（2,3-O-己基-6-脱氧-G-氨基）-{dollar} alpha，beta {dollar}和{dollar} gamma {dollar}的自组装聚集体-CD）通过循环伏安法，接触角，傅立叶变换红外光谱（FT-IR）和循环伏安法研究中性水性介质中的石英晶体微量天平测量。事实证明，改性金电极带负电荷的表面上CD衍生物的组织水平明显好于裸金电极上的CD衍生物的组织水平。 CD-修饰的电极暴露于含有微摩尔水平的二茂铁的溶液中，表明有机底物的结合发生在疏水性聚集体内部。使用量热法，荧光光谱法和分子轨道计算研究了六氟磷酸盐，高氯酸盐和三氟甲磺酸盐与美元α-美元和ββ-美元环糊精的结合常数。特别地，测得六氟磷酸酯与{β} {β}-环糊精的结合常数比先前报道的值大十倍。通过伏安法通过在中性水性介质中竞争性置换二茂铁甲醇和二茂铁羧酸盐，通过伏安法检测了{dol}β{dollar}-氨基-环糊精与磷酸根离子的络合。使用RDV技术和商业模拟软件，确定了{dollar} beta {dollar} -amino-CD与三个来宾之间的稳定性常数。

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