| 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。;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. |
