Redox-active conjugated oligo(quinoxaline)s as potential visible light-transparent charge transport building blocks were synthesized, purified, and characterized. The Suzuki–Miyaura catalyst-transfer polymerization (SCTP) in the presence of an excess of monofunctional aryl halide led to quantitative α-end-group fidelity, as confirmed by end-group analysis via MALDI-ToF mass spectrometry. A new low-pressure preparative SEC protocol was explored that can be assembled from conventional flash chromatography equipment, switching valves, and self-packed preparative SEC columns with minimal investment costs. The switching conditions in the twin-column recycling configuration enable the automated quantitative fractionation up to the octamer. The optical and electrochemical analysis of the isolated oligomers confirmed high visible light transparency (above 420 nm) and mild reduction potentials (−2.12 V vs ferrocene), which serves in combination with the facile fractionation as a starting point to efficiently prepare functional (macro-)molecular quinoxaline-based architectures. In addition, the low-pressure protocol also enables a simple and reproducible method to remove low/high molar mass shoulders in various polymer distributions.

中文翻译：

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低压制备型尺寸排阻色谱：从窄分散聚合物到单分散低聚物批次

合成、纯化和表征了作为潜在的可见光透明电荷传输结构单元的氧化还原活性共轭寡聚（喹喔啉）。通过 MALDI-ToF 质谱进行端基分析证实，在过量单官能芳基卤存在下，Suzuki-Miyaura 催化剂转移聚合 (SCTP) 可以实现定量的 α-端基保真度。探索了一种新的低压制备型 SEC 方案，该方案可以由传统的快速色谱设备、切换阀和自装制备型 SEC 柱组装而成，投资成本最低。双柱回收配置中的切换条件可实现高达八聚体的自动定量分馏。分离的低聚物的光学和电化学分析证实了高可见光透明度（420 nm以上）和温和的还原电位（-2.12 V vs 二茂铁），这与简单的分馏相结合作为有效制备功能性（宏观）的起点。 ）基于喹喔啉的分子结构。此外，低压方案还提供了一种简单且可重复的方法来去除各种聚合物分布中的低/高摩尔质量肩。