Ultrasonic Effects in Electrochemical Processes

电极过程的反应控制在合成电化学中很重要。因此，电极界面的功能改性目前受到广泛关注。在这项工作中，通过超声波效应建立了电极界面改性的新概念。这种方法控制了工作的结构。首先，对有机电极过程中的超声波效应进行了机理研究。从实验和理论考虑，证实这种效应是由于高于空化阈值的功率的超声波照射促进了电极界面的传质而引起的。因此，还考察了电解池、电极和超声波振荡器的放置对电极反应的影响，以建立超声波电化学应用的指南。结果发现，由于纵向超声波在液体中传播会引起反射、干扰和衰减，因此电极反应受成分放置的影响很大。因此，有必要考虑成分的位置。此外，超声波对有机电过程的影响已在一系列研究中得到了广泛的研究。发现有机电反应中的电流效率和/或产物选择性很大程度上受超声波影响。此外，超声辐照下电氧化聚合可以制备二维和三维致密均匀的聚合物薄膜。我们还发现，vic-二溴化物还原脱溴的立体选择性很大程度上依赖于超声频率。特别是，立体选择性是由 MHz 范围内的超声波的新效应控制的，而不是 kHz 范围内的空化现象。从机理上考虑，发现MHz范围内的超声效应是由于vic-二溴化物的超声回流所致。这一事实将产生声化学的新发展。这项研究表明，超声波为各种有机电过程中的有目的的反应控制提供了一种有用的方法。较少的

Reaction control of electrode processes is important in synthetic electrochemistry. Therefore, functionality-modification of the electrode interface has received much attention so far. In this work, a new concept for the electrode interface modification is established by means of ultrasonic effects.This approach governs the structure of the work.At first, a mechanistic study on ultrasonic effects in organic electrode processes was carried out. From experimental and theoretical considerations, it was varified that the effects are caused by promotion of mass transport in the electrode interface by ultrasonic irradiation at a power higher than the cavitation threshold value.Hence, influences of placement of electrolytic cell, electrode and ultrasonic oscillator on electrode reactions were also examined in order to establish a guideline for electrochemical application of ultrasounds. As a result, it was found that the electrode reactions were greatly affected by placement of the constituen … More ts since longitudinal ultrasonic waves traveling in liquid would cause reflection, interference and attenuation. Therefore, it is necessary to take account for the placement of constituents.Moreover, effects of ultrasounds on electroorganic processes have been extensively examined in a series of investigations. The current efficiency and / or product selectivity in electroorganic reactions were found to be greatly affected by ultrasonic waves. In addition, the two- and three-dimentionally dense and uniform polymer films could be prepared by electrooxidative polymerization under ultrasonic irradiation.It was also found that stereoselectivity in the reductive debromination of vic-dibromides remakably depends on the frequency of ultrasounds. In particular, the stereoselectivity was controlled by a novel effect of ultrasounds at MHz ranges, alternatively to the cavitation phenomenon at kHz ranges. From the mechanistic consideration, it was found that the effect of ultrasounds at MHz ranges is due to the ultrasonic reluxation of vic-dibromides. This fact would produce a new developments in sonochemistry.From this study, it was stated that ultrasounds offer a useful method for purposive reaction control in a variety of electroorganic processes. Less