本研究目的為合成新型有機鎳金屬錯合物Ni(tralen) (tralenH2 = N, N’-di(cyclohepta-2,4,6-trien-1-one-2-yl)-1,2-diaminobenzene) 並且應用於乙烯基單體如醋酸乙烯酯 (VAc)、N-乙烯基-2-吡咯烷酮 (NVP) 和丙烯酸甲酯 (MA) 的自由基聚合反應中。聚合反應加入Ni(tralen) 後其高分子分子量皆隨著單體轉化率呈線性增長，且與理論分子量相近，符合可逆-去活化自由基聚合反應的特徵。並且透過鏈延伸 (chain extension) 反應證明了聚醋酸乙烯酯之鏈尾端官能基具有活性，且從MALDI-TOF質譜儀證明其鏈尾端結構。另外，運用鏈延伸方法成功合成出了嵌端共聚物 (block copolymer) PMA-b-PVAc，說明了 Ni(tralen) 在自由基聚合反應中為有效的調控劑。接著，通過核磁共振光譜 (NMR) 和電子順磁共振光譜 (EPR) 顯示其在聚合反應中具有單電子的訊號，並利用X射線光電子能譜儀比較錯合物及巨型引發劑，推測是由 tralen 配位基上的七元環所提供單電子，故推測此配基中心金屬能做為架橋與反應中自由基結合形成休眠物種，使其具有氧化態不明確配位基 (Non-innocent ligand) 之特性。後續也針對不同金屬中心之錯合物Ni(tralen)、Zn(tralen) 和 Ca(tralen) 進行聚合結果之比較，並嘗試說明其差異。

The objective of this study is to synthesize a novel nickel complex, Ni(tralen) (tralenH2 = N, N'-di(cyclohepta-2,4,6-trien-1-one-2-yl)-1,2-diaminobenzene), and apply it in the radical polymerization reactions of vinyl monomers such as vinyl acetate (VAc), N-vinyl-2-pyrrolidone (NVP), and methyl acrylate (MA). The molecular weights of the product from the polymerization from Ni(tralen) increase linearly with monomer conversion and are close to the theoretical values, exhibiting the characteristics of reversible-deactivation radical polymerization. The chain-end functionality in poly (vinyl acetate) is demonstrated through the chain extension, and further confirmed by MALDI-TOF mass spectrometry. Additionally, the chain extension was successfully achieved to provide the block copolymer of methyl acrylate and vinyl acetate (PMA-b-PVAc), indicating that Ni(tralen) is an effective mediator for radical polymerization. To investigate the mechanism, nuclear magnetic resonance spectroscopy (NMR) and electron paramagnetic resonance spectroscopy (EPR) revealed the presence of single electron signal during the polymerization. X-ray photoelectron spectroscopy was employed to compare the complex with a macroinitiator, indicating that the single-electron is provided from the seven-membered ring on the tralen ligand to form dormant species. The electron combines with the propagating radical to form the dormant species via the metal center. Therefore, Ni(tralen) exhibits the characteristics of a complex coordinate by a non-innocent ligand. Subsequently, a comparison of the polymerization results is conducted for complexes with different metal-center, including Ni(tralen), Zn(tralen), and Ca(tralen), to investigate their differences.

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