含樹枝狀硫配位基之雙亞硝基鐵錯合物之研究

Dinitrosyl Iron Complexes Containing dendron-Thiolate Ligand

彭植(Chih Peng)

指導教授 ： 廖文峯

國立清華大學/理學院/化學系/碩士(2008年)

摘要

以3,5-dihydroxybenzyl alcohol為monomer，利用”convergent methodology”可成功合成出[G-2]-Br (5) ([G-2]-Br為第二代之poly(benzyl ether) dendron, 其focal point為Br原子)，將化合物5和[K-18-crown-6-ether]2[Fe2S2(NO)4] (7) 在THF下反應會生成dinuclear {Fe(NO)2}9-{Fe(NO)2}9 DNIC (dinitrosyl iron complex) [Fe(SR)(NO)2]2 (R = [G-2]) (8)。將化合物8與in situ產生之dendron thiolate ligand ([G-2]-S ) 反應可生成mononuclear {Fe(NO)2}9 DNIC [Fe(SR)2(NO)2]- (R = [G-2]) (9)。由IR、UV-vis、EPR、1H NMR、MS可確定化合物8及化合物9之生成。測量化合物8及化合物5之螢光放射光譜發現，以260 nm激發化合物5時可產生微弱之螢光 (~318 nm)，但以相同波長激發化合物8時，其ligand之螢光幾乎被iron-sulfur [Fe2S2] core所quench，此現象證實本次實驗所用之ligand具有light-harvesting之性質。在30 oC、有氧暗處下化合物8可穩定存在，在相同條件下加入NO-trapping agent, 2-phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl, PTIO，以254 nm光照之，由吸收光譜的變化可得知化合物8會持續地分解，測量其電子順磁光譜發現從原本PTIO之訊號完全轉為trap住NO之產物phenyltetramethylimidazoline-N-oxy, PTI之訊號 (化合物8為EPR silent)，故證實在前述光照條件下，化合物8的分解會伴隨free NO的產生。

關鍵字

雙亞硝基鐵錯合物 ； 樹枝狀高分子 ； 光分解

並列摘要

[G-2]-Br (5) and [G-2]-SCOCH3 (6) ([G-2]-X stands for second generation dendron with X at the focal point) can be synthesized from the monomer, 3,5-dihydroxybenzyl alcohol by ”convergent methodology”. Reaction of compound 5 and [K-18-crown-6-ether]2[Fe2S2(NO)4] (7) in a 2:1 molar ratio in THF can give the dinuclear {Fe(NO)2}9-{Fe(NO)2}9 dinitrosyl iron complex (DNIC) [Fe(SR)(NO)2]2 (R = [G-2]) (8). Reaction of compound 8 and dendron thiolate ([G-2]-S-) obtained from hydrolysis of compound 6 led to the production of mononuclear {Fe(NO)2}9 DNIC [Fe(SR)2(NO)2]- (R = [G-2]) (9). Both compound 8 and compound 9 were characterized by IR、UV-vis、1H NMR and MS.
From the fluorescence emission spectra, compound 5 produces fluorescence emission around 318 nm upon compound 5 irradiated at 260 nm. In contrast to compound 5, the fluorescence of dendron ligand is quenched by the iron-sulfur [Fe2S2] core when compound 8 was irradiated in the same condition. Therefore, the light-harvesting property of the dendron ligand is confirmed. Compound 8 is stable in aerated solvent at 30 oC in the dark. However, compound 8 decomposes with increasing time upon compound 8 irradiated at 254 nm in the same condition. Upon the solution of compound 8 was treated with NO-trapping agent, 2-phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl (PTIO), EPR spectrum with five-line hyperfine coupling changes into the seven-line hyperfine signal of phenyltetramethylimidazoline-N-oxy (PTI, NO-trapped product) during the photolysis. The result demonstrated that photodecomposition of compound 8 produces free NO.

並列關鍵字

dinitrosyl iron complex ； dendrimer ； photolysis

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