苯胺類衍生物與不同取代基之金屬紫質的合成、電化學及光譜學研究

本論文包含兩大部分，第一個部分是在探討含偶氮架橋結構之對苯二胺類衍生物及苯胺寡聚物的合成、電化學與光譜電化學研究。藉由改變含偶氮架橋結構之對苯二胺類衍生物的苯環上取代基，可造成氧化還原電位的不同以及改變氧化還原對的重疊程度。由透光薄層電化學法可以得知，對苯二胺類在氧化後在NIR處會產生Intervalence - Charge Transfer（IV-CT）Band。含有六個氮原子的環苯胺寡聚物(Hexamer)在電化學氧化部分，可得失四個電子，藉由改變電解質的陰離子，Hexamer與陰離子作用後，使得其氧化態被穩定，造成氧化電位往負的方向位移。在光譜電化學的部分，其光譜變化類似單體TPPD。第二部分為含有偶氮取代基及含對苯二胺取代基的金屬紫質之合成、電化學及光譜學研究。含有偶氮取代基的金屬紫質呈現了不同於以往的電化學及光譜學特性，再還原部份，紫質及偶氮取代基皆會有還原電位，藉由改變溶劑及滴定咪唑(imidazole)，可以區分出個別結構的還原，氧化部分，隨著偶氮取代基的增加，第一對氧化還原對往正的方向位移而第二對則往負的方向位移。在利用光譜電化學，可以觀察紫質氧化後光譜的變化。從電子順磁共振(EPR)光譜中可以觀察到自由基主要位於紫質的環上。藉由電化學及光譜電化學方法，觀察到MeIm在含對苯二胺類取代基的金屬紫質中移動，藉由改變電位，可使對苯二胺取代基產生氫鍵，而與鋅金屬相互競爭MeIm。電子順磁共振(EPR)光譜則呈現出自由基在金屬紫質及對苯二胺取代基之間移動。

關鍵字

電化學；光譜電化學；對苯二胺；紫質；電子順磁共振光譜

並列摘要

The thesis involves two parts. The first one includes the synthesis, electrochemical and spectral studies of phenylenediames and oligoarylamine. 4,4’-Azo-bis(triarylamine) derivatives with electron-donating groups have been synthesized. Their spectral and electrochemical characteristics have been investigated. Their first and second oxidations exhibited different degree of overlapping, depending on the electron-donating groups at the para-position of the phenyl rings. The stability of the oxidation products was monitored with UV/VIS/NIR spectroelectrochemical methods. The derivatives have very stronger IV-CT band in the near-IR range. Hexamer has been synthesized and the electrochemical and spectral porperties also have been investigated。In the electrochemical study, haxamer has totally four-electron transfer in the oxidation. With the smaller of electrolyte anion, the oxidation potetial shifted anodically. The spectral change of the hexamer in different oxidation states were similar to that of TPPD. In the second part, metalloporphyrins with azobenzene substituents have been synthesized and their electrochemical properties have been investigated. The derivatives exhibit unusual spectral and electrochemical properties. The porphyrin ring as well as azobenzene substituents could be reduced. The reduction potential varies with solvent and axial ligand. Spectroelectrochemical method is used to monitor the spectral change of the metalloporphyrins at different potential. EPR results for oxidized zinc porphyrins indicate that the radicals are localized in the porphyrin ring. ZnTMP-PD was synthesized and fully characterized. By using electrochemical and spectroelectrochemical method, ligand shuttling between zinc porphyrin and meso-phenylenediamine substituent could be monitored. EPR results indicated that charge would delocalize on ZnTMP-PD.