A catalytic cycle is described starting from a chloro-bridged dinuclear copper-tmed^‡, complex as the catalyst in the oxidation of 2,6-dimethylphenolate anions to 2,6-dimethylphenoxonium intermediates. The effect of strong base, known to accelerate the reaction, is to deprotonate 2,6-dimethylphenol (DMP) to yield its far more reactive anion. In the whole catalytic cycle dioxygen is subsequently reduced to water (i.e. in total a transfer of four electrons is involved). It appeared to be essential to use an excess of amine to obtain a maximum amount of highly active and highly specific catalyst for polymer formation. The fixed product composition obtained under the proper polymerization conditions (C-O coupling yielding polymer versus C-C coupling yielding DPQ^§) originates from the reaction of the phenoxonium intermediate with complexed DMP. Coupling of the highly favoured form of complexed DMP (which has a partial negative charge on oxygen) with C4 of the phenoxonium intermediate yields C-O coupled products. The inevitable formation of a small amount of C-C coupled DPQ (in our solvent system at 25°C, about 3%) results from the reaction of the highly unfavoured structure of DMP (which has a partial negative charge at C4) with the phenoxonium intermediate at its C4 position.

中文翻译：

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2,6-二甲基苯酚的氧化偶联聚合的机理研究：4.铜（II）基配合物催化的聚合物形成机理

催化循环中描述从氯桥双核起始铜TMED ^{‡ ，}配合物作为在2,6- dimethylphenolate阴离子氧化成2,6- dimethylphenoxonium中间体催化剂。强碱（已知可加速反应）的作用是使2，6-二甲基苯酚（DMP）脱质子化，以产生更具活性的阴离子。随后在整个催化循环中将双氧还原为水（即，总共涉及四个电子的转移）。使用过量的胺以获得用于聚合物形成的最大量的高活性和高特异性催化剂看来是必不可少的。适当的聚合条件下所得到的定影产物组成（CO偶联得到聚合物与CC偶联得到DPQ ^§）源自苯氧on中间体与复合DMP的反应。络合的DMP（在氧气上具有部分负电荷）与苯氧on中间体的C4的极受欢迎形式的偶联产生了CO偶联产物。DMP的高度不利结构（在C4处带有部分负电荷）与苯氧on中间体的反应不可避免地形成少量的CC偶联DPQ（在我们的溶剂体系中，约25％，约3％）。在其C4位置。