Analysis of Electron Transfer Reactions in Solution with the Development of High-Sensitive Detection Method for Electrogenerated Chemiluminescence using Flow-Electrolysis.

提出了一种利用脉冲电解停流法测量电致化学发光的新方法。虽然已有大量研究致力于芳香物质在非质子溶剂中正离子和阴离子自由基之间的反应所引起的ECL，但所观察到的ECL反应仅限于具有比有关分子的氧化还原电势差更小的体系。这些就是所谓的“能量不足”系统。而二苯基蒽（DPA）阳离子自由基与芘（PY）阴离子自由基之间的纯反应，由于DPA与PY同时还原的干扰，在常规方法中很难观察到。虽然这种“能量充足”的反应从未被观察到，但它的测量将有效地研究直接从单重态（s路线）发射，并获得激发态的显式信息。在本工作中，利用具有两条电解线的脉冲电解止流装置，实现了对由不同种类离子自由基组成的能量充足体系的ECL测量。在该装置中，通过独立产生阳离子自由基和阴离子自由基，在光学细胞中观察到ECL。因此，可以针对由不同种类的离子自由基组成的能量充足系统的各种反应，包括类活物种。在噻吩阳离子自由基与PY阴离子自由基的反应中，发现前驱体的加入使发射光谱发生变化，反映了溶液中复杂的电子和能量转移。此外，通过三种组分混合的测量，明确了发射特性与分子种类的关系。

New method for the measurement of electrogenerated chemiluminescence (ECL) was developed by using a pulse-electrolysis stopped-flow method. While numerous studies have been devoted to the ECL caused in the reactions between cation and anion radicals of aromatic substances in aprotic solvents, the ECL reactions ever observed have been resticted to the systems having a smaller redox potential differences than those of a molecule concerned. These are so called "energy deficient" systems. By contrast, for example, the pure reaction between diphenylanthracene (DPA) cation radical and pyrene (PY) anion radical has been very difficult to be observed in the conventional methods because of the interference by the reduction of DPA which is concurrent with the reduction of PY.Although this sort of "energy sufficient" reaction has never been observed, its measurement will be effective to study the emission directly from the singlet state (S-route) and to obtain the information on the excited states explicity. In the present work, the ECL measurement on the energy sufficient systems composed of different kind of ion radicals has become possible by using a pulse-electrolysis stopped-flow apparatus having two electrolysis lines. In this apparatus, by generating cation radicals and anion radicals independently, the ECL is observed in an optical cell. Therefore, various reactions of the energy sufficient systems composed of different kind of ion radicals can be targeted including sort-lived species. In the reaction between thianthrene cation radical and PY anion radical, it was found that the emision spectra changed with the addition of the precursors reflecting the complex electron and energy transfers in solution. In addition, the emitting properties was clarified to depend on the sort of the molecules significantly through the measurements in which three Components were mixed.