在發炎環境下一氧化氮(Nitric oxide，NO)及超氧化物(Superoxide，O2-)會被大量製造，產生的過氧亞硝酸鹽(Peroxynitrite，ONOO-)會影響生物分子的結構，且過氧亞硝酸鹽跟許多疾病有著密不可分的關係，文獻中認為體內的血紅蛋白或肌球蛋白透過一氧化氮雙加氧(Nitric oxide dioxygenation，NOD)來進一步將一氧化氮轉成硝酸鹽，來避免過氧亞硝酸鹽造成的毒性。過去許多科學家嘗試利用金屬錯合物來模擬一氧化氮雙加氧活性中心的反應機制，然而雙亞硝基鐵錯合物作為體內的一氧化氮供體，過去並沒有文獻報導過雙亞硝基鐵錯合物與超氧化物的反應性，也因此我們認為這是一個很重要的研究方向。
研究第一部分以[Fe2(μ-1,2-MePyr)2(NO)4](1)與O2-反應以及[Fe2(μ-1,2-MePyr)2(NO)4]- (1-red)與O2反應性探討為主，結果顯示以上兩個反應都會生成[(K-18-crown-6-ether)2(NO2)][Fe(μ-MePyr)4(μ-O)2(Fe(NO)2)4] (2-K2(NO2))，透過2-4-di-tert-butyl-phenol (DTBP)並沒有捕捉到DTBP硝化訊號，而晶體結構顯示此反應有亞硝酸根生成，判斷錯合物1及錯合物1-red有一氧化氮單加氧的活性。
第二部分則以錯合物1-red結構的鑑定為主，與過去文獻已發表[Fe2(μ-SEt)2(NO)4] (3-red)比較，從晶體結構、IR光譜以及EPR光譜得知錯合物1-red是定域化的{Fe(NO)2}9-{Fe(NO)2}10雙亞硝基鐵錯合物，而錯合物3-red則為非定域化的{Fe(NO)2}9-{Fe(NO)2}10雙亞硝基鐵錯合物。
第三部分則是鑑定[PPN][Fe(μ-MePyr)4(μ-O)2(Fe(NO)2)4](2-PPN)的電子結構組態，利用X光吸收光譜 (X-ray Absorption Spectroscopy，XAS)、電子順磁共振光譜（Electron Paramagnetic Resonance，EPR）確認了{Fe(NO)2}9的電子組態，穆斯堡光譜 (Mössbauer Spectroscopy)確認了錯合物2-PPN具有兩種不同的配位環境，強度約為4:1，錯合物2-PPN中心Fe原子為高自旋(high spin)之電子組態且沒有Spin crossover的現象。EPR、超導量子干涉儀(Superconducting Quantum Interference Device，SQUID)確認錯合物2-PPN結構中Fe原子彼此之間具有強反鐵磁性。針對錯合物2-PPN反應性探討，隨後利用化學還原發現錯合物2-PPN能夠被還原成錯合物1-red。
第四部份則以[Fe2(μ-SEt)2(NO)4](3)與O2-反應以及錯合物3-red與O2反應性探討為主，結果顯示錯合物3 + O2-可生成錯合物3-red + O2，反之亦然。透過DTBP並沒有捕捉到DTBP硝化訊號，研究結果顯示，錯合物3以及錯合物3-red具有類似超氧化物歧化酶(Superoxide dismutase，SOD)的活性，比照過去文獻，並沒有針對任何金屬亞硝基錯合物與O2或O2-有類似的反應性。

During the course of an inflammatory response, nitric oxide(NO) and superoxide(O2-) both are produced in quantities that surpass physiological condition. Subsequently, NO and O2- react to form peroxynitrite(ONOO-), which induce DNA damage, protein nitration, neurodegenerative diseases, to name but a few. For fear of toxicity from ONOO-, heme proteins like hemoglobin or myoglobin are known as ability to catalyze the dioxygenation of NO to produce the benign nitrate anion. Based on previous literature, a lot of scientists try to use metal-complexs to do biomimetic study about NO dioxygenation activity of heme proteins, nonetheless , there are not any research related to endogenous DNIC reactivity toward O2-. We think that it is a good direction for research.
First, we try reactivities about [Fe2(μ-1,2-MePyr)2(NO)4] (1) + O2- and [Fe2(μ-1,2-MePyr)2(NO)4]- (1-red) + O2. Interestingly, both reactions will lead the formation of [(K-18-crown-6-ether)2(NO2)][Fe(μ-MePyr)4(μ-O)2(Fe(NO)2)4] (2-K2(NO2)), which seems to be the first pentanuclear DNIC. Further we use DTBP to check these two reactions don’t pass through DTBP nitration and Complex 2-K2(NO2) crystal structure shows nitrite formation. These results indicate that Complex 1 and Complex 1-red have NO monooxygenation activity.
Second, we compare the structure between Complex 1-red and [Fe2(μ-SEt)2(NO)4]- (3-red). Although these structures both belong to {Fe(NO)2}9-{Fe(NO)2}10 DNIC, we can differentiate that Complex 1-red has localized electron structure, while Complex 3-red has delocalized electron structure from crystal structure, IR and EPR spectrum.
Third, we use a lot of instruments to characterize Complex 2-PPN because of its structural specificity. XAS and EPR spectrums show that Complex 2-PPN has {Fe(NO)2}9 electron structure. Mössbauer spectrum confirms that Complex 2-PPN has two different coordinaton environments with the ratio 4 : 1. Besides, the center Fe is high-spin electron configuration without phenomenon of spin crossover happening. EPR and SQUID spectrums indicate strong antiferromagnetic coupling. Then we find that Complex 2-PPN can be reduced to Complex 1-red by chemical reduction .
Finally, we try reactivities about [Fe2(μ-SEt)2(NO)4] (3) + O2- and Complex 3-red + O2. We find that Complex 3 + O2- lead formation of Complex 3-red + O2, and vice versa. Neither Complex 3 + O2- nor Complex 3-red + O2 demonstrate DTBP nitration. The results illustrate that Complex 3 and Complex 3-red have SOD-like activity. In comparison with literature, no metal-nitrosyl complexs have similar reactivity.

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