含吡唑雙亞硝基鐵錯合物之合成、結構鑑定與反應性探討

Synthesis, Structural Characterization and Reactivity Study of Pyrazolate-Containing Dinitrosyl Iron Complexes

曾宇霆(Yu-Ting Tseng)

指導教授 ： 魯才德

中原大學/理學院/化學研究所/碩士(2016年)

https://doi.org/10.6840/cycu201600379

摘要

本研究成功的利用吡唑(pyrazole)做為配位體，合成出一系列雙核的雙亞硝基鐵錯合物[(NO)2Fe(μ-MePyr)2Fe(NO)2]0/1-/2- (1-3)。其中三者的氧化還原交互轉換調整了Fe-Fe間距離(3.333-4.079 Å)以及兩個[FeN2Fe]平面之間的角度(120.0o-180.0o)。
第一部分我們提出穩定的{Fe(NO)2}9-{Fe(NO)2}9 DNICs [(NO)2Fe(μ-MePyr)2Fe(NO)2] (1)可以當作〖"NO" 〗^-(Nitroxyl)的提供者，能有效的將FeIII-heme中心(Fe(TPP)Cl、Hemoglobin和Myoglobin)亞硝基化，並且與化合物RRE [(NO)2Fe2(μ-SEt)2(NO)2] (RRE-SEt)和RRE [(NO)2Fe2(μ-SPh)2(NO)2] (DNIC-SPh)比較，探討晶體結構、電子結構、NO氧化態以及與〖"NO" 〗^-傳遞反應性和反應速率的差異。
第二部分我們利用[Fe(NO)2]中心可穩定小分子的特性，成功合成出以CO橋接的化合物dDNICs [Fe2(μ-MePyr)(μ-CO)(NO)2]- (4)，然後與CH2X2 (X=Cl, I, Br)反應可以將橋接的CO取代形成具有成對雙金屬甲烷(gem-dimetalloalkanes, R2CM1M2)結構的化合物dDNICs [Fe2(μ-MePyr)(μ-CH2)(NO)2]- (5)，也進一步嘗試將化合物4與CHCl3反應，初步的結果推測可能形成dDNICs [Fe2(μ-MePyr)(μ-CHCl)(NO)2]-，此結果還必須養晶得到晶體結構才能確定。
在過去文獻中，穩定的{Fe(NO)}8物種的晶體結構例子只有一個，第三部份我們成功合成出{Fe(NO)}8-{Fe(NO)}8的dMNIC [Fe2(μ-1,2-MePyr)3(NO)2]-的化合物，並且得到了晶體結構，對於自然界一氧化碳還原酶酵素催化循環的探討或許是一個重要的模型化合物，反應機制以及電子結構還必須進一步的研究與探討。

關鍵字

雙亞硝基鐵錯合物；次硝酸傳遞

並列摘要

In this work, dinuclear dinitrosyliron complexes (DNICs) containing pyrazolate bridging ligands [(NO)2Fe(μ-MePyr)2Fe(NO)2]0/1-/2- were successfully synthesized. The reversible redox transformations [Fe(μ-MePyr)Fe(NO)2]2 ⇌[Fe(μ-MePyr)Fe(NO)2]2−⇌[Fe(μ-MePyr)2Fe(NO)2]22− regulates the Fe…Fe distance between 3.333-4.079 Å and the angles between two [FeN2Fe] planes 120.0o-180.0o.
First, stable dinuclear {Fe(NO)2}9 DNIC [Fe(μ-MePyr)(NO)2]2 (1) was discovered as a potent nitroxyl donor for nitroxylation of FeIII-heme centers (such as Fe(TPP)Cl, Hemoglobin and Myoglobin), we also compare the electronic structure, NO oxidative state of complex 1 and the nitroxyl transfer reactivity with the neutral Roussin’s Red Esters (RRE) {Fe(NO)2}9 [(NO)2Fe2(μ-SEt)2(NO)2] (RRE-SEt) and the mononuclear DNIC [(NO)2Fe2(μ-SPh)2(NO)2] (DNIC-SPh).
Second, because of the characterization of small molecules stablized by [Fe(NO)2] centers, the DNIC [Fe2(μ-MePyr)(μ-CO)(NO)2] − (4) with mixed CO─thiolate-bridged ligands were synthesized, further reaction of CH2X2 (X=Cl, I, Br) ensued to yielded the mixed CH2─thiolate-bridged ligands DNIC [Fe2(μ-MePyr)(μ-CO)(NO)2]− (4), and also reacts to CHCl3 with complex (4), here we suggest that dDNICs [Fe2(μ-MePyr)(μ-CHCl)(NO)2]− was synthesized, we still trying to get the single crystal to prove this result.
In the previous,there is only one crystal structure of stable {Fe(NO)}8 species , the last part, the stable dMNICs {Fe(NO)}8-{Fe(NO)}8 [Fe2(μ-1,2-MePyr)3(NO)2]– were successfully synthesized, it maybe a important modal complex of the key intermiates in the catalytic cycles of bacterial respiratory NO reductases (NorBC) and flavodiiron NO reductases (FNORs).The reaction mechanism and the electronic structure will be further studied.

並列關鍵字

Dinitrsyliron complex；Nitroxyl transfer

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