Studies On Novel Catalytic Wave Of Organic Compound--Parallel Catalytic Wave

Polarographic catalytic wave, as a branch of polarographic current, is a useful tool in increasing analytical sensitivity, and studying electrode process and reaction kinetics. The polarographic catalytic wave includes two main types. The first is parallel catalytic wave, which mainly concerns the catalytic wave of inorganic ions in the presence of oxidizing agent. In this process, the low valent intermediate product is oxidized by oxidizing agent to regenerate the original reactant, resulting in the increase of polarographic current. The second is catalytic hydrogen wave. It includes the catalytic hydrogen wave of platinum-group elements and organic compounds. The catalytic hydrogen wave is observed at less negative potentials than the usual wave of hydrogen discharge, which the catalysts diminish the hydrogen over-potential accelerating the hydrogen ion discharge. In general, catalytic hydrogen wave has a high analytical sensitivity. From the literatures reported, the study on polarographic catalytic wave for inorganic metal ions has made a great progress. Different classes of catalytic waves such as parallel catalytic wave, catalytic wave of inorganic complex and catalytic hydrogen wave of platinum-group elements have been studied in detail and applied widely in geological, environmental and metallurgical areas.It is known that the number and diversity of organic compounds is remarkable. They are closely related to lives of human being. In reaction processes of organic compound, there are free radical products. Therefore, the studies on the catalytic waves of organic compounds in the presence of oxidizing agent are of the significance. From the production mechanisms, the polarographic catalytic waves of organic compound are divided into parallel catalytic wave and parallel catalytic hydrogen wave. The parallel catalytic waves are ascribed to the chemical regeneration of reducible groups via oxidation of unstable intermediates such as free radicals in the presence of oxidizing agent. As the important part of the polarographic catalytic wave,the parallel catalytic hydrogen waves are attributed to further catalysis of original catalytic hydrogen wave of organic compounds by oxidizing agent. The catalytic waves have a higher analytical sensitivity than the corresponding catalytic hydrogen waves. This work involves the two parts:1. Study on novel method of reaction kinetics of atomic hydrogenAtomic hydrogen is the active intermediate of many biological reaction processes. And the study on atomic hydrogen has become a hotspot in life science, biological medicine, new energy exploitation and environmental protection. The core of parallel catalytic hydrogen wave of organic compound is to study the reaction of atomic hydrogen with oxidizing agent. Using the parallel catalytic hydrogen wave of organic compound, atomic hydrogen can be produced quantitatively, and the reaction kinetics of atomic hydrogen can be studied at given conditions. Based on the parallel catalytic hydrogen wave, a novel method on reaction kinetics of atomic hydrogen is proposed, and the rate constant equation of reaction of atomic hydrogen with oxidizing agent is deduced and verified by experiments. Experiments show that pyridine, a-picoline and a, a'-lutidine at ca. -1.76 V (vs. SCE) produce a catalytic hydrogen wave in borate buffer. The catalytic hydrogen wave can be catalyzed by H2O2, yielding a parallel catalytic hydrogen wave. Because in parallel catalytic hydrogen process atomic hydrogen is an intermediate product, atomic hydrogen is oxidized by H2O2 in the presence of H2O2. The rate constant is calculated by experimental data, and the rate constant is in good agreement with those determined by pulse radiolysis-electron paramagnetic resonance methods. And this method is superior to the methods in simplicity and availability.2. Studies on parallel catalytic hydrogen waves of different organiccompoundsThe studies on parallel catalytic hydrogen waves of organic compounds enrich polarographic catalytic wave and impregnate the new en...