Monatshefte für Chemie - Chemical Monthly ( IF 1.7 ) Pub Date : 2021-09-14 , DOI: 10.1007/s00706-021-02842-3 Adnan Zahirović 1 , Emira Kahrović 1
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Abstract
Cyclic voltammetry was used to provide the electrochemical evidence of catalytic catechol oxidation by ruthenium organometallics of chloro-substituted 2’-hydroxychalcones and to get partial insight into the mechanistic process. The catalytic properties of organometallics were measured in methanol, ethanol, and acetonitrile and the solvent effect was confirmed. The assignation of peaks in cyclic voltammograms was made systematically by characterizing all individual components of the catalytic mixture. The cathodic peak arising from electrochemical reduction of catalytically formed quinone near − 0.4 V vs. Ag/AgCl evolves over time and can be used for kinetic measurements. The formation of new peak at + 0.1 V vs. Ag/AgCl indicates that catechol oxidation to quinone proceeds via semiquinone formation in the presence of ruthenium organometallics. The kinetic profile of the catechol oxidation in the presence of ruthenium organometallics differs from each other and the rates of oxidation are well correlated with spectrophotometric measurements. Several advantages of electrochemistry over spectrophotometry were addressed. The obtained results demonstrate that electrochemistry can be used as a comparative method to spectrophotometry to measure the catalytic catechol oxidation and provide useful qualitative and quantitative data on kinetics and mechanism of catechol oxidation.
Graphic abstract
中文翻译：
2'-羟基查耳酮的钌 (II) 有机金属化合物氧化儿茶酚的电化学证据
摘要
循环伏安法用于提供氯代 2'-羟基查耳酮的钌有机金属催化邻苯二酚氧化的电化学证据，并部分了解该机理过程。在甲醇、乙醇和乙腈中测量了有机金属化合物的催化性能，并证实了溶剂效应。通过表征催化混合物的所有单独组分，系统地确定循环伏安图中的峰。由催化形成的醌在接近 - 0.4 V 与 Ag/AgCl 的电化学还原产生的阴极峰随时间演变，可用于动力学测量。在 + 0.1 V vs. Ag/AgCl 处形成新峰表明，在钌有机金属化合物存在下，邻苯二酚氧化成醌是通过半醌形成的。在钌有机金属存在下儿茶酚氧化的动力学曲线彼此不同，氧化速率与分光光度测量密切相关。解决了电化学相对于分光光度法的几个优点。所得结果表明，电化学可用作分光光度法的比较方法来测量催化邻苯二酚氧化，并提供有关邻苯二酚氧化动力学和机理的有用定性和定量数据。
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