Carbon Dioxide Reduction to Methanol Catalyzed by Mn(I) PNP Pincer Complexes under Mild Reaction Conditions

Well-defined Mn­(I)
hydrido carbonyl PNP pincer-type complexes were
tested as efficient and selective nonprecious transition metal catalysts
for the reduction of CO2 to MeOH in the presence of hydrosilanes.
The choice of reaction temperature and type of silanes proved to be
pivotal to achieve fast reactions and high selectivity to the methoxysilyl-
vs silylformate derivatives in DMSO. The catalytic data are complemented
by DFT calculations, highlighting a stepwise CO2 reduction
mechanism centered on the Mn catalyst without metal-to-ligand cooperation.

结构明确的Mn(I)氢羰基PNP钳型配合物被用作高效且选择性优异的非贵重过渡金属催化剂，可在氢硅烷存在下将二氧化碳（CO₂）还原为甲醇（MeOH）。研究表明，反应温度的选择与硅烷的种类对于实现快速反应，以及在二甲基亚砜（DMSO）中获得甲氧基硅基产物相较于甲硅烷基甲酸酯产物的高选择性至关重要。本研究通过密度泛函理论（DFT）计算对催化实验数据进行补充，揭示了以Mn催化剂为核心、无金属-配体协同作用的分步式CO₂还原机制。