| 摘要: | 本論文主要是藉由化學合成的方法模擬鐵-鐵氫化酵素，並合成一系列四鐵四硫之化合物 [{μ,μ,κ2-3,6-(OSitBuMe2)2-bdt}2(μ-PPh2)2(μ-H)xFe4(CO)8][B(C6F5)4]x (bdt = 1,2-benzenedithiolate，x = 0 (3)，x = 1 (4)，x = 2 (5) )及雙鐵雙硫化合物 [(μ-3,6-R2-bdt)Fe2(CO)6] (R = OCO2C2H5 (7)，OCH2CONH2 (8)，OC3H6SO3 (9) )。
在四鐵四硫化合物的部分，當 bdt上的H被推電子基 OSitBuMe2取代後，而得到化合物 [{μ,μ,κ2-3,6-(OSitBuMe2)2-bdt}2(μ-PPh2)2Fe4(CO)8] (3)，四鐵四硫催化劑產氫催化速率kcat值從1393 M-1 s-1 增加至3308 M-1 s-1，速率增加約2.5倍。當化合物3和 [(Et3Si)2H][B(C6F5)4] 反應，成功合成出來一次質子化和二次質子化的產物4和5。
在雙鐵雙硫化合物的部分，以水溶性的官能基修飾雙鐵雙硫化合物，合成出化合物7、8、9。紫外光-可見光光譜的結果，指出化合物7、8並不溶水，而化合物9在水中的最大溶解度為9.42 mM。化合物7、8在有機相的酸催化效率，分別為kcat = 392 M-1 s-1與kcat = 351 M-1 s-1，催化效果與無任何官能基取代的 [(μ-bdt)Fe2(CO)6] (kcat = 632 M-1 s-1) 相近。另外，在水相下對化合物9在水溶液下催化醋酸產生氫氣，其kcat值為1446 M-1 s-1，較相似衍生物在有機溶劑下之催化效果佳。
;A series of tetra-iron complexes [{μ,μ,κ2-3,6-(OSitBuMe2)2-bdt}2(μ-PPh2)2(μ-H)x Fe4(CO)8][B(C6F5)4]x (bdt = 1,2-benzenedithiolate，x = 0 (3)，x = 1 (4)，x = 2 (5) ) and di-iron complexes [(μ-3,6-R2-bdt)Fe2(CO)6] (R = OCO2C2H5 (7)，OCH2CONH2 (8)，OC3H6SO3 (9) ) have been synthesized and characterized.
Electrochemical analysis of complex 3, bearing electron rich groups OSitBuMe2 on bdt site, has an apparent improvement in kcat value, from 1393 M-1 s-1 to 3308 M-1 s-1. Intermediates 4 and 5 were successfully synthesized with the reaction of 3 and [(Et3Si)2H][B(C6F5)4].
Complexes 7-9, developed as fundamental models of the two-iron subsite in the [Fe-Fe]-hydrogenase enzyme active site show water solubility by virtue of different water-soluble functional groups in corporated into the benzenedithiolate unit that bridges two Fe(CO)3 moieties. These complexes were characterized by IR, NMR, UV-vis spectroscopy and electrochemistry. Apart from complex 9, complexes 7 and 8 are not soluble in water. The kcat value of 7 (392 M-1 s-1) and 8 (351 M-1 s-1) are similar to [(μ-bdt)Fe2(CO)6] (kcat = 632 M-1 s-1). However, the kcat value of 9 in the presence of water is 1446 M-1 s-1, shows a higher performance than other diiron dithiolate derivatives in organic solvent. |
