| 摘要: | 本研究是以化學方法合成模擬鐵-鐵仿生氫化酵素的活化中心，具有苯硫之雙鐵化合物接上OCH2COOtBu的酯類官能基，主要目的是增加水溶性，合成出
雙鐵雙硫化合物[{μ-3,6-(OCH2COOtBu)2-bdt}Fe2(CO)6] (bdt = 1,2-benzenedithiolate，1)、[K][{μ-3,6-(OCH2COOtBu)2-bdt}(μ-PPh2)Fe2(CO)5] (2)，[TBA][{μ-3,6-(OCH2COOtBu)2-bdt}(μ-PPh2)Fe2(CO)5] (TBA+ = nBu4N+ (3))，將化合物2進行氧化反應，合成出在空氣中穩定的四鐵四硫化合物[{μ,μ,κ2-3,6-(OCH2COOtBu)2-bdt}2(μ-PPh2)2Fe4(CO)8 (4)。化合物1‒4，都經過紅外線光譜儀(FTIR)、核磁共振儀(NMR)、元素分析(EA)、質譜(MS)等對以上化合物進行鑑定，化合物2‒4以X-ray單晶繞射解析出其固態結構。
化合物1、3、4分別利用循環伏安法探討氧化還原行為，化合物1在乙腈(MeCN)溶液中，有一組可逆的還原訊號，在氧化部分有多組的不可逆氧化訊號，化合物3在乙腈(MeCN)溶液中，一組半可逆的還原訊號，一組可逆的氧化訊號，化合物4在二氯甲烷CH2Cl2)溶液中，有兩組可逆的還原訊號，一組可逆的氧化訊號，化合物1跟3在乙腈(MeCN)溶液中，以乙酸(acetic acid)作為質子來源，化合物4在二氯甲烷(CH2Cl2)溶液中，以三氟乙酸(trifluoroacetic acid)作為質子來源，進行電化學的催化實驗，推測其產氫機制。
Series of Fe2S2 complexes were synthesized for [FeFe]-hydrogenases modeling study. A in order to increase the water solubility of Fe2S2 complexes, the bridging benzenedithiolate was functionalized with ester group OCH2COOtBu. Complexes [{μ-3,6-(OCH2COOtBu)2-bdt}Fe2(CO)6] (bdt=1,2-benzenedithiolate, 1), [K][{μ-3,6-(OCH2COOtBu)2-bdt}(μ-PPh2)Fe2(CO)5] (2), [TBA][{μ-3,6-(OCH2COOtBu)2-bdt}(μ-PPh2)Fe2(CO)5] (TBA+ = nBu4N+ (3)) were successfully synthesized. Furthermore, a air-stable tetra-iron complex [{μ,μ,κ2-3,6-(OCH2COOtBu)2-bdt}2(μ-PPh2)2Fe4(CO)8 (4) was obtained by oxidizing complex 2. Compounds 1-4 were characterized by Fourier-transfer infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), elemental analysis (EA), mass spectrometry (MS), and X-ray single crystal analysis for compounds 2-4.
Compounds 1, 3, and 4 use cyclic voltammetry to investigate the redox behavior. The cyclic voltammetry of 1 in MeCN have a reversible reduction and multiple sets of irreversible oxidation at oxidized. The cyclic voltammetry of 3 in MeCN have a quasi-reversible reduction and a reversible oxidation. The cyclic voltammetry of 4 in CH2Cl2 have two reversible reduction and a reversible oxidation. The catalytic ability of complexes 1 and 3 toward hydrogen evolution reaction was investigated in MeCN in the presence of acetic acid and complexes 4 in CH2Cl2 of trifluoroacetic acid. Electrochemical catalytic experiments are performed to predict its hydrogen production mechanism. |
