A macromoleculeâmetal complex with redox centres on the same polymer chain of partially quaternized poly(1-vinylimidazole)(QPVIm) has been designed. In this complex, Co(tfacacen)(tfacacen =N,Nâ²-ethylenebis(1,1,1-trifluoro-4-iminopentan-2-one), a CoIIâSchiff base complex, and quaternized imidazolium residues, an oxidizing agent, are both linked to a polymer backbone. The mechanism of the electron-transfer reaction between Co(tfacacen) and the quaternized imidazolium residue on this macromolecular complex have been investigated. The electron-transfer rate depends linearly on the concentration of CoII residues and the degree of quaternization but is independent of the concentration of quaternized imidazolium residue. These dependencies indicate that, under the experimental conditions, an intra-polymer electron-transfer reaction occurs in this system. The reaction product formed by reduction of the quaternized imidazolium residue was identified by means of 1H NMR and absorption spectroscopies. The results show that the predominant reduction product is 3-ethyl-4-imidazoline-containing polymer.
我们设计了一种在部分季
铵化聚(
1-乙烯基咪唑)(QPVIm)的同一聚合物链上具有氧化还原中心的大分子
金属复合物。在这种复合物中,Co(tfacacen)(tfacacen =N,N²-
乙烯双(
1,1,1-三氟-4-亚氨基戊烷-2-酮)(一种 CoIIâSchiff 碱复合物)和季
铵化
咪唑残基(一种氧化剂)都与聚合物骨架相连。研究人员对 Co(tfacacen)与该大分子复合物上的季
铵化
咪唑残基之间的电子转移反应机理进行了研究。电子转移率与 CoII 残基的浓度和季
铵化程度成线性关系,但与季
铵化
咪唑残基的浓度无关。这些依赖性表明,在实验条件下,该体系中发生了聚合物内部的电子转移反应。通过 1H NMR 和吸收光谱鉴定了季
铵化
咪唑残基还原形成的反应产物。结果表明,主要的还原产物是含 3-乙基-4-
咪唑啉的聚合物。