帳號:guest(18.221.146.223)          離開系統
字體大小: 字級放大   字級縮小   預設字形  

詳目顯示

以作者查詢圖書館館藏以作者查詢臺灣博碩士論文系統以作者查詢全國書目
作者(中文):莊雅嵐
作者(外文):Ya-Lan Chuang
論文名稱(中文):鎳-硫化合物之合成與反應性:鎳/鐵氫化酵素之鎳活化中心之生化擬態模型化合物
論文名稱(外文):Synthesis and reactivity of Nickel(III)-thiolate complexes: relevance to the Nickel site of [NiFe] Hydrogenase
指導教授(中文):廖文峯
指導教授(外文):Wen-Feng Liaw
學位類別:碩士
校院名稱:國立清華大學
系所名稱:化學系
學號:933461
出版年(民國):95
畢業學年度:94
語文別:中文
論文頁數:66
中文關鍵詞:金屬酵素氫化酵素
外文關鍵詞:metalloenzymehydrogenase
相關次數:
  • 推薦推薦:0
  • 點閱點閱:464
  • 評分評分:*****
  • 下載下載:16
  • 收藏收藏:0
取等比例的[PPN][Ni(CO)(2-S-C4H3S)3]和P(C6H3-3-SiMe3-2-SH)3在THF溶液中反應,可形成[PPN][NiII(2-S-C4H3S)P((C6H3-3-SiMe3-2-S)2(C6H3-3-SiMe3-2- SH))] (1),而取等比例的NiCl2(PPh3)2和P(C6H3-3-SiMe3-2-SH)3在THF溶液中反應,則可得到[NiII(PPh3)P((C6H3-3-SiMe3-2-S)2(C6H3-3-SiMe3-2-SH))] (3)。這兩個NiII化合物為四配位,扭曲平面四邊形結構。其中,pendant thiol與Ni和Ni上的S原子會產生分子內交互作用力。經由X-ray單晶繞射鑑定結構和光譜分析,證實化合物1具有[Ni…H-S](1a)/ [Ni-S…H-S](1b)分子內的交互作用力,而化合物3的分子內作用力則屬於[Ni…H-S]交互作用力。
化合物1、3 通入O2後,會分別形成[PPN][NiIII(2-S-C4H3S)P((C6H3-3-SiMe3- 2-S)3)] (2)和[NiIII(PPh3)(P((C6H3-3-SiMe3-2-S)3)] (4),皆為五配位,扭曲雙三角錐結構。化合物2在CH2Cl2溶液時,CH2Cl2會行dechlorination反應,化合物2會轉換成[PPN][NiIII(Cl)P((C6H3-3-SiMe3-2-S)3)]。在CO的環境下,化合物2會行reductive elimination,產生[PPN][NiII(CO)P((C6H3-3-SiMe3-2-S)3)]。而因為化合物4的terminal ligand是PPh3,是中性且是一個供給電子能力較弱的ligand,使其在CH2Cl2溶液中無法轉變成[PPN][NiIII(Cl)P((C6H3-3-SiMe3-2-S)3)],且在CO的環境下也無法行reductive elimination,產生[PPN][NiII(CO)P((C6H3-3-SiMe3-2- S)3)]。利用環電位儀(Cyclic Voltammetry)測化合物2、4的NiIII/II氧化還原電位分別為-1.16 V、-0.83 V (vs Cp2Fe/Cp2Fe+),皆為可逆的反應。對於這幾個化合物的幾何結構、光譜特性與反應機制可以對鎳鐵-氫化酵素做有意義的解釋。
The reaction of [PPN][Ni(CO)(2-S-C4H3S)3] with 1 equiv of P(C6H3-3-SiMe3-2- SH)3 in THF leads to form the four-coordinated complex, [PPN][NiII(2-S-C4H3S)P- ((C6H3-3-SiMe3-2-S)2(C6H3-3-SiMe3-2-SH))] (1). In the same preparation way, the reaction of NiCl2(PPh3)2 with 1 equiv of P(C6H3-3-SiMe3-2-SH)3 in THF leads to yield another four-coordinated complex, [NiII(PPh3)P((C6H3-3-SiMe3-2-S)2(C6H3-3- SiMe3-2-SH))] (3). Complexes 1 and 3 display a similar structural geometry, distorted square planar with a S-H proton interacting with both nickel center and sulfur atom. The presence of intramolecular [Ni…H-S]/[Ni-S…H-S] interactions in complexes 1 and 3 were verified in the solid state by the observation of the lower IR vS-H band and further confirmed by X-ray study. Oxidation of complexes 1 and 3 by O2 results in the formation of a mononuclear, distorted triganol bipyramidal [PPN][NiIII(2-S-C4H3S)- P((C6H3-3-SiMe3-2-S)3)] (2) and [NiIII(PPh3)(P((C6H3-3-SiMe3-2-S)3)] (4), respectively. Complex 2 undergoes dechlorination of CH2Cl2 solution to generate [PPN][NiIII(Cl)P((C6H3-3-SiMe3-2-S)3)]. In addition, complex 2 reacts with exogenous CO to produce [PPN][NiII(CO)P((C6H3-3-SiMe3-2-S)3)]. In contrast to complex 2, complex 4 is inert in the presence of CH2Cl2 and CO. This results imply that PPh3 is a weaker donating ligand than thiolate ligand (2-S-C4H3S). This result is further confirmed by the result of the cyclic voltammograms of complex 2 and 4. Complexes 2 and 4 display a reversible NiIII/II redox processes with E1/2 = -1.16 V, -0.83 V (vs Cp2Fe/ Cp2Fe+), respectively. The structure, activity, and spectroscopic properties of these complexes may show some insight about the nickel site in bimetallic Ni-Fe active site of [NiFe] Hydrogenase.
中文摘要
Abstract
第一章:緒論
第二章:實驗部分
第三章:結果與討論
第四章:結論
Reference
1. (a) Adams, M. W. W.; Stiefel, E. I. Curr. Opin. Chem. Biol. 2000, 4, 214-220. (b) Casalot, L; Rousset, M. TRENDS in Microbiol. 2001, 9, 228-237.
2. (a)Volbeda, A.; Charon, M. H.; Piras, C.; Hatchikian, E. C.; Frey, M.; Fontecilla-
Camps, J. C. Nature 1995, 373, 580-587. (b) Happe, R. P.; Roseboom, W.; Pierik,
A. J.; Albracht, S. P. J Nature 1997, 385, 126.
3. (a) Higuchi, Y.; Yagi, T.; Yasuoka, N. Structure 1997, 5, 1671-1680. (b) Higuchi, Y.; Ogata, H.; Miki, K.; Yasuoka, N.; Yagi, T. Structure 1999, 7, 549-556.
4. Rousset, M.; Montet, Y.; Guigliarelli, B.; Forget, A.; Asso, M.; Bertrand, P.;
Fontecilla-Camps, J. C.; Hatchikian, E. C. Proc. Natl. Acad. Sci. U.S.A. 1998, 95,
11625-11630.
 
 
 
 
第一頁 上一頁 下一頁 最後一頁 top
* *