Kotnik Tomaž, Žerjav Gregor, Pintar Albin, Žagar Ema, Kovačič Sebastijan
National Institute of Chemistry, Department of Polymer Chemistry and Technology, Hajdrihova 19, 1000 Ljubljana, Slovenia.
National Institute of Chemistry, Department of Inorganic Chemistry and Technology, Hajdrihova 19, 1000 Ljubljana, Slovenia.
ACS Macro Lett. 2021 Oct 19;10(10):1248-1253. doi: 10.1021/acsmacrolett.1c00457. Epub 2021 Oct 1.
Conjugated porous polymers through the emulsion-templating polymerization process are typically prepared as monoliths, and the emulsions are cured via metal-catalyzed cross-coupling reactions. Herein, we report the design and synthesis of well-defined, millimeter-sized conjugated porous polymer beads by combining an oil-in-oil-in-oil (O/O/O) double emulsion as a de novo template and an amino-catalyzed Knoevenagel condensation reaction as a polymerization chemistry to cure such emulsions. The 1,4-phenylenediacetonitrile is reacted with aromatic multialdehydes in the presence of piperidine, and a series of metal-free poly(arylene cyano-vinylene) beads are prepared. All beads exhibit 3D-interconnected microcellular morphology and substantial semiconducting properties, such as strong light harvesting ability in the visible light region with electrochemical band gaps in the range of 2.05-2.33 eV. Finally, the promising photocatalytic activity of these conjugated beads is demonstrated for a model sulfoxidation reaction under visible light irradiation, and near quantitative conversions with excellent chemoselectivities (>99%) are obtained.
通过乳液模板聚合过程制备的共轭多孔聚合物通常制成整体材料，乳液通过金属催化的交叉偶联反应固化。在此，我们报告了通过将油包油包油（O/O/O）双乳液作为从头模板与氨基催化的Knoevenagel缩合反应作为聚合化学方法相结合来固化此类乳液，从而设计并合成出尺寸为毫米级、结构明确的共轭多孔聚合物珠粒。对苯二乙腈在哌啶存在下与芳香族多醛反应，制备出一系列无金属的聚（亚芳基氰基亚乙烯基）珠粒。所有珠粒均呈现三维互连的微孔形态和显著的半导体性质，例如在可见光区域具有强光捕获能力，电化学带隙在2.05 - 2.33 eV范围内。最后，在可见光照射下，这些共轭珠粒对模型硫氧化反应展现出良好的光催化活性，并获得了接近定量的转化率以及优异的化学选择性（>99%）。
