【作者】 王晔；

【导师】 金葆康；

【作者基本信息】 安徽大学 ， 分析化学， 2007， 硕士

【摘要】 本文首先综述了酚醌一类有机小分子电化学的研究进展。酚醌类化合物结构式中含有酚羟基和羰基官能团，是氧化还原反应的活性中心，其大多具有良好的电化学反应活性，是电子传递的优良载体。研究酚醌类化合物的电化学反应机理情况，有助于加深了解它们在生物体内所参与的代谢过程。本文重点研究了结构和电化学性质具有代表性的几种酚醌类化合物：中药成份丹皮酚和丹参酮ΠA、1，4-对苯醌（BQ）、邻萘醌等。主要工作概括如下：1、研究了碱性磷酸盐缓冲溶液体系中的丹皮酚在固体电极上的电化学吸附氧化行为。与苯酚的电化学性质比较表明，碱性溶液中丹皮酚在电极表面上发生类似的不可逆的氧化。氧化产物发生随后化学反应，在电极表面生成致密的不导电聚合物膜。利用超微电极技术研究了丹皮酚电化学氧化的动力学，时间分辨快速扫描红外光谱电化学的实验结果表明电极表面的聚合物膜是芳醚类聚合物。利用交流阻抗技术研究了所产生的聚合物膜。2、运用红外差谱、时间分辨红外快速扫描等光谱电化学技术研究了BQ在乙腈溶剂中的电化学氧化还原过程。实时的跟踪研究反应物、生成物及中间体随电位、时间的变化。首次清楚观察到半醌自由基中间体在还原或是氧化过程中的生成和消去，采用二维相关谱技术，对时间分辨红外光谱中各谱峰之间的相关信息进行深入的分析，从一个新的角度验证了BQ反应机理。同时利用低温时间分辨红外快速扫描手段考察了半醌自由基中间体的存在寿命与温度的关系，反应速率常数与中间体寿命的倒数成正比，根据阿累尼乌斯公式k=Ae^-E／RT，由斜率可获得反应活化能。3、研究β-（1，2）萘醌、丹参酮ΠA这两种邻醌类化合物的电化学性质。在固体电极（裸铂电极）采用循环伏安法、差分脉冲法、双电位阶跃方法、计时电量法等多种电化学手段，并借助现场红外光谱电化学技术，从分子水平上探讨其电化学反应过程中分子结构的变化。与BQ比较发现邻醌类化合物不是简单的两步单电子过程，推测中间可能存在复杂的后行化学反应，诸如半醌自由基发生二聚，半醌自由基与有机体系乙腈中的微量水发生质子化偶合现象等。更多还原

【Abstract】 Achievements of electrochemical studies of quinone compounds and phenoliccompounds were reviewed firstly in this paper. These two type compounds wererelevant through redox cycling. There are carbonyl groups （C=O） and hydroxylgroups （-OH）, which are active center in redox cycling. Most of them areelectroactive molecules which play an important role in redox electron-transportchains of living systems and can be used in molecular electronics. Paeonol, and aseries of quinones （1, 4-Benzoquinone,β-1, 2-Naphthoquinone, TanshinoneⅡA）, withrepresentative electrochemical characters were chosen as our research subject. Thispaper mainly covered the following research works:1, The electrochemical behaviours of paeonol on different solid electrodes werestudied by cyclic voltammetry in alkaline PBS solution. Comparative studies werecarried out by using phenol under similar experimental conditions. The paeonolelectrochemistry oxidation is irreversible, which produces a compact insulatedpolymeric film on the electrode surface, and the electrochemistry oxidation dynamicprocess was studied on ultramicroelectrode. The insulated polymeric film was provedpolymer arylether by real-time in-situ rapid scan IR spectroscopy. The insulatedpolymeric film modified platinum electrode was studied by electrochemicalimpedance techniques.2, In-situ rapid scan FTIR and In-situ difference FTIR Spectroelectrochemistrytechniques were used to track the whole electrochemical redox process of the BQ asvariable time and potential. The intermediate semiquinone anion radical appearanceand disappearance were clearly observed. Two-dimension （2D） spectral correlationanalysis was employed to determine the sequence of spectral emergence shown inrapid scan FTIR spectra. The result showed us a new insight into BQ electrochemicalreduction reaction mechanism. The relationship between the intermediate existent lifeand the temperature was studied. Based on the results, a kinetics simulation wasperformed according to the electrochemical reaction mechanism, and kineticparameter is concident with the Arrhenuis equation Arrhenius equation (k=Ae^-E/RT). 3, Electrochemical characters of two types of ortho-quinones were studied bycyclic voltammetry, differential pulse voltammetry, chronocoulometry, doublepotential step chronamperomery and so on. In-situ FTIR was also employed as apowerful tool in obtaining information on structural and moclecular properties duringthe process of electrochemical reaction. Compared with BQ, The electrochemicalprocess of ortho-quinones is not a simple two-step one-electron cathodic reduction.Actually there are some other complicated chemical processes, such as: semiquinoneradical dimerization, semiquinone radical protonation, and so on, followed byelectrochemical reduction.更多还原