多功能鐵、鈷及鈀金屬錯合物的合成、鑑定與催化

Synthesis, Characterizations, and Catalysis of Multifunctional Iron, Cobalt, and Palladium Complexes

周思仲(Siz-Chung Chou)

指導教授 ： 張慕傑

國立臺灣大學/理學院/化學研究所/碩士(2021年)

https://doi.org/10.6342/NTU202101799

摘要

鈀、鉑等貴金屬在近代的科學發展中被發掘可做為有效的催化劑，且廣泛地被使用在催化各種小分子的反應中。但貴金屬缺點為較為貴重且較不易取得，為解決此一缺陷，我們選用價格相對較便宜、且地殼含量較高之第一列過渡金屬元素來解決此問題 (如鐵、鈷、鎳、銅等金屬)。為了進一步加強金屬中心的催化能力，我們加入配位基和金屬反應形成金屬錯合物。
透過金屬-配位基協同作用 (Metal-Ligand Cooperation) 及金屬-金屬協同作用 (Metal-Metal Cooperation) 兩大作用的幫助下，可以穩定金屬不常見的氧化數及催化涉及電子、質子轉移的反應。設計好一個具備以上特性的酞嗪 (Phthalazine) 配位基H2L後，和兩種不同的金屬鹽類反應後，我們成功得到鐵(II)錯合物 4、鈷(II)錯合物 5，利用核磁共振光譜法及X-ray單晶繞射來確認溶液中跟固體的結構，皆為單核金屬錯合物。藉由循環伏安法研究電化學上氧化環原的性質，觀察是否具有可逆的氧化環原峰可幫助催化反應。而鈷錯合物(II) 5 發現在加入氧化劑的狀況下會形成另一鈷錯合物(III) 6，其中有一個H2L發生了碳氫鍵活化作用 (C-H Bond Activation)。最後，我們使用H2L和鈀金屬鹽類反應後得到了鈀(II)錯合物 7，同樣為單核金屬錯合物。
而完成對錯合物的性質和結構鑑定後，我們分別對Suzuki 偶聯反應、開環聚合、醇類氧化反應及二氧化碳環加成反應進行催化，並比較各個錯合物的優缺點，以及跟原先文獻上結果的差異。

關鍵字

金屬-配位基協同作用 ； 金屬-金屬協同作用 ； 多功能配位基 ； 多功能金屬錯合物 ； 催化反應

並列摘要

Nowadays, noble metals, such as palladium and platinum, have been discovered as effective catalysts. They are also widely used to catalyze various small molecule reactions. However, these noble metals are expensive and scarce. In order to solve the problem, we choose the first row transition metals (iron, cobalt, nickel, and copper) which are relatively cheap and abundant on the curst. So as to further enhance the catalytic ability of the metal center, we utilize ligands to react with metals to form metal complexes.
With the help of the Metal-Ligand Cooperation and Metal-Metal Cooperation, these two synergetic cooperation can stabilize the uncommon oxidation states of metals and catalyze reactions involving electron and proton transfer. After designing a phthalazine-based ligand H2L and reacting with two different metal salts, we obtained iron (II) complex 4, cobalt (II) complex 5. The structure of the solution state and the solid state can be confirmed by using nuclear magnetic resonance spectroscopy and X-ray single crystal diffraction. All the results show that these complexes are mononuclear metal complexes. Besides, cyclic voltammetry is used to study the electrochemical properties of the complexes, and observe whether there is a reversible reduction peak to help catalyze the reaction. Cobalt complex 5 has been discovered that it can be oxidized to cobalt complex (III) 6 when an oxidant is added, and C-H bond activation has occurred to one of the ligands. Last, we used H2L to react with palladium salts, and got palladium complex (II) 7 which is also a mononuclear metal complex.
After completing the identification of the properties and structure of the complexes, we catalyzed the Suzuki coupling reaction, ring-opening polymerization, alcohol oxidation reaction and carbon dioxide cycloaddition reaction, and compared their catalytic activity to the original literature.

並列關鍵字

metal-ligand cooperation ； metal-metal cooperation ； multifunctional metallic complex ； catalytic reaction

參考文獻

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