{Fe(NO)2}10 雙亞硝基鐵金屬錯合物的合成與鑑定及其產生過氧化亞硝酸根反應機制研究

Synthesis and Characterization of {Fe(NO)2}10 Dinitrosyl-Iron Complex for Peroxynitrite Generation Mechanism Study

蔡旻宏(Min-hung Tsai)

指導教授 ： 洪政雄

國立中央大學/理學院/化學系/碩士(2015年)

摘要

利用配位基2-phenyl-1,10-phenanthroline與Fe(CO)2(NO)2在THF溶液下反應，得到中性{Fe(NO)2}10雙亞硝基鐵錯合物[(2-Ph-1,10-Phen)Fe(NO)2] (1)，並且完成光譜及單晶結構鑑定。以紅外線光譜電化學對錯合物1進行氧化，可測得一{Fe(NO)2}9雙亞硝基鐵錯合物1+的訊號（υNO = 1765及1835 cm−1），此訊號可用化學氧化劑(NOBF4)氧化得到相同結果．若以氧氣氧化錯合物1則會得到六配位(side-on; η2-O2) {Fe(NO)2}9 [(2-Ph-1,10-Phen)Fe(NO)2(O2−)] (1+−O2−) (υNO = 1715及1785 cm−1, υO−O = 1020 cm−1)，另外以錯合物1+與KO2/18-Crown-6-ether反應亦可得到相同的訊號。此組NO訊號在紅外線光譜的吸收能量與文獻報導過的五配位{Fe(NO)2}9[(TMEDA)Fe(NO)2I](υNO = 1719及1773cm−1)非常接近．以18O2進行實驗後與O2結果比較可得υO−O = 987 cm−1(∆υO−O = υ(18O2) −υ(16O2) = −33cm−1)。錯合物1+−O2−可以繼續反應並產生一不穩定的{Fe(NO)}8 peroxynitro-bound MNIC ([(2-Ph-1,10-Phen)Fe(NO)(ONOO−)] (2))。由錯合物2可分解產生•NO2(g)並且對2,4-di-tert-butyl-6-nitrophenol (DBP)進行硝化反應更確認有peroxynitrite的生成。反應最終推測是得到一{Fe(NO)}7的MNIC(υNO = 1792 cm−1)。以Griess test得知•NO2(g)也可能因為誘發DBP產生自由基進行硝化反應產生NO2− (nitrite)。在反應產生的氣體產物中偵測到O2的存在，推測是另一個伴隨產生NO2−的可能性，因此推測了另一可能的反應途徑。

關鍵字

{Fe(NO)2}10 ； 雙亞硝基鐵金屬錯合物 ； 過氧化亞硝酸根

並列摘要

The reaction of 2-phenyl-1,10-phenanthroline and Fe(CO)2(NO)2 in THF afforded a {Fe(NO)2}10 DNIC, [(2-Ph-1,10-Phen)Fe(NO)2] (1), which was corroborated with spectroscopic and structural characterizations. FT-IR measurement confirmed that appling a constant oxidation potential on 1 and simultaneously monitoring stretching frequency change resulted in {Fe(NO)2}9 [(2-Ph-1,10-Phen)Fe(NO)2]+ (1+) with υNO at 1765 and 1835 cm−1, which were also achieved through chemical oxidation of complex 1 using NOBF4 as an oxidant. Utilization of O2 as an oxidant, however, obtained a six-coordinate {Fe(NO)2}9 [(2-Ph-1,10-Phen)Fe(NO)2(O2−)] (1+−O2−) (υNO = 1715 and 1785 cm−1; υO−O = 1020 cm−1) in which the O2 unit coordinated to the iron center with a side-on(η2-O2) mode. Complex 1+−O2− was also achieved from the reaction of 1+and KO2/18-Crown-6-ether. The υNO of 1715 and 1785 cm−1 is similar to reported five-coordinate {Fe(NO)2}9 [(TMEDA)Fe(NO)2I] with υNO at 1719 and 1773 cm−1. The presence of superoxo coordination was verified by reaction of 1 with 18O2 to observe the υO−O shifted from 1020 cm−1 to 987 cm−1(∆υO−O = −33 cm−1). Complex 1+−O2− continuously transformed into a reactive {Fe(NO)}8 peroxynitro-bound MNIC ([(2-Ph-1,10-Phen)Fe(NO)(ONOO−)] (2)), which spontaneously decomposed to release •NO2(g). In the presence of 2,4-di-tert-butyl-6-nitrophenol (DBP), the detection of nitrated product confirmed the formation of peroxynitrite(ONOO−). The final product of metal complex was proposed to be a {Fe(NO)}7 MNIC with υNO = 1792 cm−1. Treating Griess test reagent to the resulted reaction solution detected the formation of nitrite, suggesting•NO2(g) initiated a radical reaction for the following phenol nitration and resulted in NO2−. On the other hand, the detection of O2 from the gas product in the reaction vessel may also imply another pathway to the nitrite formation, and a plausible mechanism was proposed to account for the observed reactions.

並列關鍵字

{Fe(NO)2}10 ； Dinitrosyl-Iron Complex ； Peroxynitrite

參考文獻

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(2) Culotta, E.; Koshland, D. E. Science 1992, 258, 1862.

(3) Murad, F. Angew. Chem., Int. Ed. 1999, 38, 1857.

(4) Furchgott, R. F. Angew. Chem., Int. Ed. 1999, 38, 1870.

(5) Ignarro, L. J. Angew. Chem., Int. Ed.1999, 38, 1882.