In this work, we investigate using carbon dioxide (CO₂) as an inexpensive reaction medium during the photocatalytic oxidative coupling of primary amines to the corresponding imines. As a model system, we study the reaction of benzylamines in acetonitrile over a potassium poly(heptazine imide) photocatalyst (K-PHI). We use CO₂ or argon (Ar) to saturate the reaction solution and the reactor headspace, and blue light (461 nm) to drive the reaction. When compared to the more expensive Ar, CO₂ boosts the conversion rate by creating a reaction intermediate with better electron donor properties. We also validate the influence of water content on the imine formation efficiency, and we observe higher catalytic activity of K-PHI, compared to a standard mesoporous graphitic carbon nitride (mpg-CN).

中文翻译：

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使用廉价的CO ₂促进苄胺的光催化氧化的优势

在这项工作中，我们研究了在伯胺与相应的亚胺的光催化氧化偶联过程中使用二氧化碳（CO ₂）作为廉价的反应介质。作为模型系统，我们研究了乙腈中苄胺在聚庚庚二酰亚胺钾光催化剂（K-PHI）上的反应。我们使用CO ₂或氩气（Ar）饱和反应溶液和反应器顶部空间，并使用蓝光（461 nm）驱动反应。与更昂贵的Ar，CO _2相比通过产生具有更好电子给体性质的反应中间体来提高转化率。我们还验证了水含量对亚胺形成效率的影响，与标准的介孔石墨氮化碳（mpg-CN）相比，我们观察到K-PHI的催化活性更高。