Photochemical and Electrochemical Reduction of Carbon Dioxide to Carbon Monoxide Mediated by (2,2′‐Bipyridine)tricarbonylchlororhenium(I) and Related Complexes as Homogeneous Catalysts
抄録
<jats:title>Abstract</jats:title><jats:p>[<jats:italic>fac</jats:italic>‐Re(bpy) (CO)<jats:sub>3</jats:sub>Cl] (bpy = 2,2′‐bipyridine) is an efficient homogeneous catalyst for the selective and sustained photochemical or electrochemical reduction of CO<jats:sub>2</jats:sub> to CO. A quantum yield of 14% and a faradic efficiency of 98% were measured in the presence of excess Cl<jats:sup>−</jats:sup> ions. The photochemical process took place under visible‐light irradiation and consumed a tertiary amine as electron donor. A formato‐rhenium complex was isolated in the absence of excess Cl<jats:sup>−</jats:sup> ions. Substitution by Cl<jats:sup>−</jats:sup> ion generated free formate, but no CO was detected. Luminescence measurements showed that the tertiary amine quenches the metal‐to‐ligand charge‐transfer excited state of the rhenium complex <jats:italic>via</jats:italic> a reductive mechanism, with a rate constant of 3.4 × 10<jats:sup>7</jats:sup>M<jats:sup>−1</jats:sup>S<jats:sup>−1</jats:sup>. The 19e‐complex [Re(bpy) (CO)<jats:sub>3</jats:sub>X]<jats:sup>−</jats:sup> produced either photochemically or electrochemically appears to be the active precursor in the CO‐generation process. Detailed spectroscopic studies on <jats:sup>13</jats:sup>C‐enriched carbonyl‐rhenium and formato‐rhenium complexes derived from <jats:sup>13</jats:sup>C‐enriched CO<jats:sub>2</jats:sub> were performed in order to confirm the origin of the products and to study the exchange of the ligands. A mechanism for the present CO<jats:sub>2</jats:sub> photoreduction process is presented; it involves separate pathways for CO and formate generation, in which the [Re(bpy) (CO)<jats:sub>3</jats:sub>X] complex plays the role of <jats:italic>both the photoactive and the catalytic center</jats:italic>.</jats:p>
収録刊行物
-
- Helvetica Chimica Acta
-
Helvetica Chimica Acta 69 (8), 1990-2012, 1986-12-10
Wiley
- Tweet
キーワード
詳細情報 詳細情報について
-
- CRID
- 1363670319038104832
-
- NII論文ID
- 80003290883
-
- ISSN
- 15222675
- 0018019X
-
- データソース種別
-
- Crossref
- CiNii Articles