Preparation of Clay Monolayr and its Application of Electrode Modifier for Asymmetric Syntheses

本课题实现了一种粘土矿物超薄膜的制备。该方法是基于单层疏水粘土颗粒在空气-水界面上逐层沉积（LB法）。用傅里叶变换红外光谱、x射线衍射测量和原子力显微镜观察研究了薄膜的结构。结果，得到了厚度控制在纳米尺度上的均匀薄膜。所述粘土层取向与所述薄膜表面平行。这种薄膜已被用来修饰玻碳电极。通过将修饰电极浸入氧化还原活性金属配合物的水溶液中，膜嵌入金属配合物并具有电活性。电极上循环伏安图的测量表明，膜中电活性物质的扩散常数与膜的厚度密切相关。它随着薄膜层数的增加呈指数增长。这种依赖性表明，载流子输运是以跳跃机制进行的。该修饰电极现已应用于萘酚的不对称合成成旋光性双萘酚。

In this project, the preparation of the ultra-thin film of a clay mineral has been achieved. The method is based on the layr-by-layr deposition of the monolayr of hydrophobic clay particles on an air-water interface (LB method). The structure of a film has been studied with FT-IR spectroscopy, X-ray diffraction measurements and atomic force microscopic observations. As a result, a homogenous film is obtained whose thickness is controlled on a nanometer scale. The clay layrs are oriented parallel with the film surface. Such a film has been used to modify an glassy carbon electrode. By immersing the modified electrode in an aqueous solution of a redox active metal complex, the film intercalates the metal complex and becomes electroactive. The measurements of cyclic voltammogram on the electrode have revealed that the diffusion constant of an electroactive species in a film depends on the thickness of a film critically. It increased exponentially with the layr number of a film. The dependence suggests that carrier transport takes place in a hopping mechanism. The modified electrode is now applied for the asymmetric syntheses of naphthol into optically active binaphthol.