低價數及低配位的鐵、鈷及鎳錯合物的合成

Synthesis of Low - Valent and Low - Coordinate Iron, Cobalt and Nickel Complexes

廖敬維(Jing-Wei Liao)

指導教授 ： 蔡易州

國立清華大學/理學院/化學系/碩士(2014年)

https://doi.org/10.6843/NTHU.2014.00259

摘要

本篇論文主要是研究低配位、低價數之雙核鐵、鈷及鎳金屬錯合物的合成。第一部份為雙核鎳錯合物， 有鑑於2009及2011年本實驗室成功利用苯上2,6位取代基為雙異丙基及苯上2,6位取代基為雙乙基的雙氮基脒配基合成出了[Ni(µ-κ2-HC(NDipp)2]2 (Dipp = 2,6-diisopropylphenyl)及[Ni(µ-κ2-HC(NDep)2]2 (7) (Dep = 2,6-dethylphenyl)，在此我們將配基的立體阻礙縮小，將取代基改為甲基，並合成出一系列的雙核鎳金屬錯合物。利用Li [HC(NDmp)2] (Dmp = 2,6-dimethyphenyl)與2當量的碘化鎳反應可得到Ni2(I)2(µ-I)2 (µ-κ2-HC(NDmp)2) Li(THF)2(OEt2)2 (1) ; 而與0.5當量的碘化鎳反應可得到三片配基橋接在兩個鎳金屬上的雙鎳錯合物Ni2[(µ-κ2-HC(NDmp)2]3 (2)，將錯合物1與1當量的Li[HC(NDmp)2]於90 °C下反應可得到兩個碘原子橋接在三個鎳原子間的Ni3(µ-κ2- HC(NDmp)2)3(µ3-I)2 (3)。若將1與4當量的鉀石墨反應應可得到Ni2[(µ-κ2-HC(NDmp)2]2 (4)，4也可由1與1當量的Li[HC(NDmp)2]與4當量的鉀石墨還原而得到，此法的產率會比錯合物1直接還原來得高。將1與雙異丙基取代的去質子化配基Li[HC(NDipp)2]與4當量的鉀石墨還原可得到混合配基的Ni2(µ-κ2-HC(NDmp)2)(µ-κ2-HC(NDipp)2) (5)，此錯合物為文獻上尚未被報導過的低配位數一價金屬混合配基錯合物。而將1與雙乙基取代的去質子化配基Li[HC(NDep)2]與4當量的鉀石墨還原，可得到三組錯合物，其中一組為Ni2(µ-κ2-HC(NDmp)2)(µ-κ2-HC(NDep)2) (6)，另外兩組分別為[Ni(µ-κ2-HC(NDmp)2)]2 (4)及[Ni(µ-κ2-HC(NDep)2)]2 (7)。
第二部分為雙核鐵和鈷錯合物，利用Li[HC(NDmp)2]配基與氯化亞鐵及氯化亞鈷反應後分別得到環形四鐵錯合物[Fe(µ-Cl)(µ-κ2-HC(NDmp)2)]4 (8)及雙鈷錯合物Co2(Cl)(µ-Cl)[ClLi(THF)3][µ-κ2-HC(NDmp)2]2 (12)，再以鉀石墨對此二錯合物還原，皆得到三片配基橋接在兩個鐵上的雙核錯合物Fe2[(µ-κ2-HC(NDmp)2]3 (9)及Co2[(µ-κ2-HC(NDmp)2]3 (13) ; 我們將配基的立體障礙提高，將取代基改為乙基，利用Li[HC(NDep)2]配基與氯化亞鐵及氯化亞鈷反應後得到Fe2(Cl)(µ-Cl)[κ1-THF][µ-κ2-HC(NDep)2]2 (10)及Co2(Cl)(µ-Cl)[ClLi(THF)3][µ-κ2-HC(NDep)2]2 (14)，再以鉀石墨對此二錯合物還原，結果仍為三片配基橋接在兩個金屬上的Fe2 [(µ-κ2-HC(NDep)2]3 (11)及Co2 [(µ-κ2-HC(NDep)2]3 (15)。

關鍵字

鎳-鎳鍵

並列摘要

Treatment of the lithiated amidinate ligand Li[HC(NDmp)2] (Dmp = 2,6-dimethylphenyl) with 2 equiv of NiI2 afforded the dinickel complex Ni2(I)2 (µ-I)2(µ-κ2-HC(NDmp)2) Li(THF)2(OEt2)2 (1). However, reaction of the amidinato Li[HC(NDmp)2] ligand with 0.5 equiv of NiI2 resulted in the formation of the lantern-type dinuclear complex, Ni2[(µ-κ2-HC(NDmp)2]3 (2). Subsequent reduction of 1 by KC8 resulted in the isolation of the dinickel bisamidinate compound Ni2[(µ-κ2-HC(NDmp)2]2 (4). Compound 4 can be alternatively prepared by reaction of 1 with 1 equiv of Li[HC(NDmp)2] and then 4 equiv of KC8. The later route produced 4 with a better yield. Moreover, reaction of 1 with Li[HC(NDipp)2] (Dipp = 2,6-diisopropylphenyl) and 4 equiv of KC8 furnished the unprecedented low-coordinate heteroleptic dinickel complex Ni2(µ-κ2-HC(NDmp)2)(µ-κ2-HC(NDipp)2) (5). Reaction of 1 with Li[HC(NDep)2] (Dep = 2,6-diethylphenyl) and 4 equiv of KC8 generated three products, which are the heteroleptic complex Ni2(µ-κ2-HC(NDmp)2)(µ-κ2-HC(NDipp)2) and two homoleptic dinickel compounds [Ni(µ-κ2-HC(NDmp)2)]2 and [Ni(µ-κ2-HC(NDep)2)]2. Unfortunately, we cannot separate the heteroleptic species Ni2(µ-κ2-HC(NDmp)2)(µ-κ2-HC(NDipp)2 from the other two homoleptic compounds.
In the second part of this thesis, reaction of the amidinate ligand Li[HC(NDmp)2] with anhydrous FeCl2 or CoCl2 produced the cyclic tetrairon complex, [Fe(µ-Cl)(µ-κ2-HC(NDmp)2)]4 (8) and the “ate” dicobalt complex Co2(Cl)(µ-Cl)[κ1-ClLi(THF)3][µ-κ2-HC(NDmp)2]2 (12), respectively. KC8 reduction of 8 or 12 led to the formation of the lantern complex M2[(µ-κ2-HC(NDmp)2)]3 (9: M = Fe; 13: M = Co). When the slightly more steric hindered amidinate ligand (Li[HC(NDep)2]) was employed to react with anhydrous FeCl2 and CoCl2, the lantern type complexes, Fe2[(µ-κ2-HC(NDep)2]3 (11) and Co2[(µ-κ2-HC(NDep)2]3 (15) are also the major products.

並列關鍵字

Nickel-Nickel bond

參考文獻

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