We report on new ruthenium complexes as catalysts for the efficient transformation of CO₂ into formic acid employing basic ionic liquids as buffering media. Remarkably, these complexes catalyze the hydrogenation of CO₂ selectively and without employing strong bases, which improves the sustainability of the process when compared to common base-mediated technologies. The molecular catalyst design relies on donor-flexible and synthetically versatile pyridylidene amide (PYA) ligands which allows the ligand architecture to be varied in a controlled manner to gain valuable insights for the improvement of catalyst performance. Modification of the ligand properties directly influence the catalytic process by shifting the turnover limiting step, the reaction mechanism and the stability upon the acidification of the reaction media and provide access to high-performance systems reaching turnover numbers of several thousands and turnover frequencies up to 350 h⁻¹.

我们报告了新型钌配合物，作为使用碱性离子液体作为缓冲介质将CO ₂有效转化为甲酸的催化剂。明显地，这些络合物催化CO ₂的氢化与常见的碱介导技术相比，可以选择性地且无需使用强大的碱，从而提高了流程的可持续性。分子催化剂的设计依赖于供体柔性和合成用途广泛的吡啶亚酰胺（PYA）配体，该配体允许以可控的方式改变配体的结构，从而获得宝贵的见解，以改善催化剂的性能。配体性质的改变通过改变周转限制步骤，反应机理和反应介质酸化后的稳定性直接影响催化过程，并提供了达到数千次周转次数和高达350次周转频率的高性能系统的途径h ^-1。