| 摘要: | 自然界中的鐵鐵氫化酶能夠可逆地催化氫氣的氧化和質子的還原反應，由於其高效的催化質子還原產氫活性，鐵鐵氫化酶活性中心的結構和功能模擬引起了生物無機化學家們極大的興趣。雙亞硝基鐵化合物(dinitrosyl iron complex，DNICs)，是傳遞一氧化碳分子的重要化合物。因此我們計畫合成Fe的有機金屬化合物，一個廉價高效的製氫催化劑，其中具有NHC當作配為基來穩定結構，同時具有non-innocent特性的NO配位基，並分別以2-(dimethylamino)benzenethiol與2-aminothiophenol兩不同配位基，紅外線光譜與循環伏安圖譜證實在所配位基的改變對鐵中心的影響不大，結構仍然很相似，在-1.4 V與-1.45 V有著相當好的氧化還原能力，但當氮端鹼性的提升能提高產氫的效率，化合物4較化合物3的電催化質子還原活性良好。
The [FeFe]-hydrogenase is a biological catalyst for reversible proton reduction to hydrogen which have caught the attention of a broad range of researchers. Dinitrosyl iron complexes (DNICs) have been known to be a possible from for nitric oxide release and storage. We will design a new types of hydrogen catalyst.We use [FeFe]-hydrogenase as a reference, simplify to synthesize a stable metal compound, a cheap and efficient hydrogen-producing catalyst.
Three types of oxidation states of non-innocent ligand, nitric oxide (nitrosyl / nitric oxide / nitroxyl), was utilized. NHC (N-Heterocyclic Carbene), a good σ-donor and resonance property. Both of them would stabilize the structure. The 2-(dimethylamino) benzenethiol and 2-aminothiophenol ligand were adopted as pendent base. Ours potential models complex (IMes)(SR)Fe(NO)2 (IMes=1, 3-bis(2, 4, 6-trimethylphenyl
-imidazol-2-ylidene, R =C6H4-o-NH2) (3) and (IMes)(SR’)Fe(NO)2 ( R’=C6H4-o-NMe2) (4) , both of them are easy to synthesize and thermal/air stable. The IR spectrum point out the chemical environment of iron center is similar. Complex 3 and 4 show a good redox ability at E1/2=-1.40, ipa/ipc =0.94 of 3, E1/2=-1.45, ipa/ipc =0.96 of 4, respectively. When acid added, complexe 4 be a good electrochemical catalysis for H2 production than complex 2, the Lewis base functional group (dimethylamine terminal) enhance the efficiency. |
