Centre of Spectroelectrochemistry, Department of Electrochemistry and Conducting Polymers, IFW Dresden, Helmholtzstr. 20, D-01069 Dresden, Germany.
Magn Reson Chem. 2011 Nov;49(11):725-9. doi: 10.1002/mrc.2819. Epub 2011 Oct 3.
A combined in situ NMR and in situ ESR spectroelectrochemical study of a reaction mechanism is presented detecting and describing the whole number of paramagnetic and diamagnetic intermediates and final products in an electrode reaction. While in situ NMR spectroelectrochemistry provides a powerful method for the study of structural or electronic changes of diamagnetic molecules in any electrochemical reaction mechanism, in situ ESR spectroelectrochemistry is the method of choice to detect paramagnetic structures and to characterise their electronic state via the g-value and hyperfine splitting in redox reactions. To demonstrate the power of this combination of magnetic spectroscopies in electrochemistry, the reduction of p-benzoquinone to hydroquinone is followed by both these spectroelectrochemical methods at selected pH values, thus considering the influence of the proton on the reaction mechanism. The results of both in situ spectroelectrochemical methods at the same redox system are used to get the complete reaction mechanism of p-benzoquinone at electrodes in aqueous solutions.
本文提出了一种结合原位 NMR 和原位 ESR 光谱电化学研究反应机制的方法，用于检测和描述电极反应中所有顺磁和抗磁中间产物和最终产物。原位 NMR 光谱电化学为研究任何电化学反应机制中抗磁分子的结构或电子变化提供了强大的方法，而原位 ESR 光谱电化学是检测顺磁结构并通过 g 值和在氧化还原反应中精细结构分裂来表征其电子态的首选方法。为了展示这种磁光谱电化学组合在电化学中的强大功能，本文选择在选定 pH 值下通过这两种光谱电化学方法来跟踪对苯醌到氢醌的还原，从而考虑质子对反应机制的影响。在相同的氧化还原体系下，这两种原位光谱电化学方法的结果被用来得到水溶液中电极上对苯醌的完整反应机制。
