Synthesis, Electrochemical and Spectral Properties of Metallo 5-(4-Carboxy-Phenylethynyl)-10,20-Biphenylporphines

[[abstract]]我們已經發現 ZnCA(PE)xBPP 是不錯的光敏劑，並且正對紫質與其取代基之間距離長短進行探討。為了增進我們對此紫質的了解，本論文針對其中心金屬之不同作探討。我們先將 ZnCAPEBPP 中心金屬去金屬化，再分別運用不同金屬鹽類對紫質做金屬化。我們發現在莫耳吸收係數方面，除了 Cl-MnCAPEBPP Soret band 因為 LMCT 關係有著分裂且較紅移吸收峰外，其他金屬位置皆相近，吸收度則以 ZnCAPEBPP 最大。循環伏安法方面，則除了CoCAPEBPP外大部分紫質皆可看到紫質變成 anion 的還原波，H2CAPEBPP、Cl-FeCAPEBPP 則可以看到紫質變成 di-anion 的還原波。而CoCAPEBPP可以看見其鈷金屬離子的氧化還原訊號。我們亦可看見似乎是CAPE取代基還原的訊號。電化學光譜方面，除了得到Mn、Fe、Co金屬還原的光譜圖配合其他紫質文獻，以支持我們在循環伏安法對紫質金屬價數的推論，並且由 ZnCAPEBPP、Cl-MnCAPEBPP 我們似乎可以得到CAPE 取代基還原的光譜圖。但是有些電位的光譜我們無法獲得。經過一連串實驗我們相信各種金屬離子對紫質造成的影響有ㄧ定的規律，相信藉由本篇論文獲得的資訊，可以幫助我們運用金屬離子改變紫質特性這方面的資訊。[[abstract]]We have found that ZnCA(PE)xBPP are fairly good candidates to study dye-sensitized solar cell (DSSC) and related studies. In order to address the effects of the central metals, we prepare H2CAPEBPP, ZnCAPEBPP, CuCAPEBPP, NiCAPEBPP, CoCAPEBPP, Cl-FeCAPEBPP and Cl-MnCAPEBPP and investigate their electronic absorption, electrochemical and spectroelectrochemical properties. UV-Visible absorption wise, the Soret and Q bands of these porphyrins located in a similar region except for the Mn analogue. For Cl-MnCAPEBPP, Soret bands are significantly split and red-shifted. This is likely due to the d-π interactions between the MnIII ion and the porphyrin π-conjugation system. Among these porphyrins, ZnCAPEBPP has the strongest B band. Upon CV experiments, these porphyrins show several reversible reductive waves. Metal-centered reductions are observed for the Co, Fe, Mn complexes. Although somewhat overlapped with the porphyrin ring reduction waves, we believe that the CAPE substituent is the first to reduce (prior to the porphyrin ring reductions) for Zn, Ni, Cu and H2CAPEBPP, followd by porphyrin ring reduction. Further spectro-electrochemical studies of ZnCAPEBPP show that these two reductions can be well separated. For the Mn analogue, the CAPE reduction and the porphyrin ring reduction can also be spectrally separated. For the rest of the CAPEBPPs, the two processes are much more difficult to distinguish. On the other hand, no reversible oxidation reactions are observed in the experimental conditions except for CoCAPEBPP (CoII/CoIII).[[note]]碩