Reduction of CO2 on a Tricarbonyl Rhenium(I) Complex: Modeling a Catalytic Cycle

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• 作者：Jay Agarwal ; Richard P. Johnson ; Gonghu Li
• 刊名：Journal of Physical Chemistry A
• 出版年：2011
• 出版时间：April 7, 2011
• 年：2011
• 卷：115
• 期：13
• 页码：2877-2881
• 全文大小：793K
• 年卷期：v.115,no.13(April 7, 2011)
• ISSN：1520-5215

文摘

Tricarbonyl rhenium(I) complexes, such as Re(bpy)(CO)₃Cl where bpy = 2,2鈥?bipyridyl, have demonstrated superior activity in catalyzing CO₂ reduction in the presence of sacrificial electron donors. We have utilized density functional theory (DFT) to investigate a potential pathway for formate production via a rhenium鈭抙ydride insertion mechanism in the presence of triethylamine (TEA). On the basis of prior studies, we re-examined the role of TEA and studied a catalytic cycle for CO₂ reduction in which TEA functions as both the hydrogen atom and the electron donor for reducing CO₂ into formate. The catalytic cycle is found to be exothermic with inclusion of solvation and may be viewed as a two-electron reduction of CO₂ because the net result is a transfer of hydride from TEA to CO₂. In addition, we have identified structures of key intermediates in the CO₂-reduction process and found that the insertion step has a very modest barrier in acetonitrile. These findings provide a molecular-level understanding to formate production via CO₂ reduction mediated by transition-metal complexes. A theoretical investigation is underway to elucidate the formation of carbon monoxide, another common product in Re-catalyzed CO₂ reduction.