Study of the Electron Transfer Reactions of Organic Anions by Means of Electrochemical and Thermochemical Methods.

本项目的目的是获得各种类型的有机镁试剂与芳香羰基和硝基底物反应的结构-反应性关系的半定量基础。从以前的结果，在所有的反应中的电子转移的参与建议的基础上形成的副产物，由于典型的自由基过程。一些镁试剂的给电子能力（EDA）以前也是通过氧化峰电位来估算的，因此本项目的第一个计划是通过电化学方法测量各种底物的还原电位来估算它们的电子接受能力（EAA）。反应<DETA>物的氧化和还原电位之间的差值（E）被认为是各个反应中电子转移效率的估计值。用极谱分析仪测定了羰基和硝基化合物在THF中的还原电位。 ...更多信息 以四苯基硼酸二联苯基铬（I）为内标，对Bu_4NC_（10_4）体系进行了研究。格里茨纳，林茨大学。在<DELTA>ArMgBr、ArSMgBr、ArNHMgBr、ArN（MgBr）_2和AroMgBr等15种镁试剂的反应中，将所得到的E值与正常和异常（自由基）产物的相对产率进行了关联。丹麦工业大学霍尔姆教授对我们的新型含Mg-N-Mg键的镁试剂的反应进行了研究。通过使用使用流动技术的霍尔姆的机器，该计划是不成功的，因为他所应用的流速不适合我们的反应。然而，用Beckmann温度计进行的分批技术，所观察到的温度升高几乎完全与基于电化学测量提出的分类雅阁，这一结果仍是初步的，EDA-EAA概念的阐述仍在进行中。所获得的关联将有助于机理研究。各种镁试剂的合成应用也在不断发展。少

The purpose of the project is to obtain a semiguantitative basis for the structure-reactivity relationship in the reactions of various types of organomagnesium reagents with aromatic carbonyl and nitro substrates. From the previous results, the involvement of electron transfer in all the reactions is suggested on the basis of the formation of by-products due to typical radical processes. The electron-donating abilities(EDA) of some magnesium reagents was also previously estimated by their oxidation peak potentials.Thus, the first plan of this project is to measure electrochemically the reduction potentials of various substrates as the estimate for their electron accepting abilities(EAA). The value of difference(<DETA>E) between the oxidation and reduction potentials of reactants is taken as the estimate for the efficiency of electron transfer in the individual reactions. By means of a polarographic analyzer, the reduction potentials of carbonyl and nitro compounds were measured in THF- … More Bu_4NC10_4 system by use of bis(biphenyl)chromium(I) tetraphenyl borate as internal reference granted by the courtesy of Prof. G. Gritzner, University of Linz. The obtained<DELTA>E value was correlated to the relative yields of normal and abnormal (radical) products in fifteen reactions of magnesium reagents including ArMgBr, ArSMgBr, ArNHMgBr, ArN(MgBr)_2, and AroMgBr.The second plan of the thermochemical study was to apply the exothermal nature of the electron transfer in Grignard reaction established by Prof. T. Holm, Denmark Technical University, to the reactions of our new magnesium reagent having Mg-N-Mg bond. By use of Holm's machine using flow technigue, the plan was unsuccessful because the flow rate applied by him was not suitable for our reaction. However, by use of a batch technigue using a Beckmann's thermo meter, the observed elevation of temperature was almost completely in accord with the classification proposed on the bais of electrochemical measurements.The result is still a preliminary one, and the elaboration of the EDA-EAA concept is in progress: The obtained correlation will contribute to the mechanistic studies. The synthetic applications of various types of magnesium reagents are also in progress. Less