對苯二胺及其衍生物的合成與電化學性質研究

本論文主要分為兩大主題，第一個主題是在探討對苯二胺衍生物的合成、電化學與光譜電化學研究。本研究探討對苯二胺衍生物的苯環及甲基取代對於氧化電位的影響，並研究其光譜電化學。研究發現，當對苯二胺上的氫以苯環的取代數目越多時，氧化電位越正，表示苯環數目越多，越不易氧化；而當甲基的取代數目越多時，氧化電位越負，表示甲基取代數目越多，越容易氧化。第二個主題則是研究對苯二胺衍生物藉由滴定不同pKa的含氮鹼，以電化學的方式觀察化合物氧化後誘導與不同的鹼產生氫鍵的能力。在循環伏安法中可以得知，此類的對苯二胺衍生物，當含氮鹼加入後，第二個氧化波隨著含氮鹼濃度的增加會出現新的氧化波，且含氮鹼的pKa大小會影響第三個氧化還原波的電位。這指出，當對苯二胺上的氫經過氧化後會與含氮鹼的氮原子誘導產生氫鍵。

關鍵字

對苯二胺；氫鍵；受體；電化學；光譜電化學

並列摘要

This work has included two topics. The first one has been concerned with p-phenylenediamines synthesis, electrochemistry and spectroscopy. The phenyl and methyl substituents of p-phenylenediamine derivatives exhibit effects on the oxidation potential and spectra. Phenyl group substitution on p-phenylenediamines caused the oxidation potential to be more positive while methyl groups made the compounds easier to oxidize. A correlation of oxidation potential with the number of substituents was delineated. The second topic is about the electrochemically induced hydrogen bonding of the p-phenylenediamine derivatives with pyridines and imidazoles. During the oxidative scans of p-phenylenediamine derivatives in presence of bases, a new redox couple was observed and the second oxidation wave disappeared gradually. The potential of the new redox couple exhibited linearity with the pKa of the base. A reaction scheme involving complex formation upon redox reactions is proposed.