NHC‐Containing Manganese(I) Electrocatalysts for the Two‐Electron Reduction of CO2. Issue 20 (2nd April 2014)

• Record Type: Journal Article
• Authors: Agarwal, Jay; Shaw, Travis W.; Stanton, Charles J.; Majetich, George F.; Bocarsly, Andrew B.; Schaefer, Henry F.
• Is Part Of: Angewandte Chemie international edition. Volume 53:Issue 20(2014)
• Page Start: 5152
• Page End: 5155
• Publication Date: 2014-04-02
• Subjects: carbon dioxide -- catalysis -- electrochemistry -- manganese -- N‐heterocyclic carbenes; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201311099
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The synthesis and characterization of the first catalytic manganese N‐heterocyclic carbene complexes are reported: MnBr( N ‐methyl‐ N ′‐2‐pyridylbenzimidazol‐2‐ylidine)(CO)3 and MnBr( N ‐methyl‐ N ′‐2‐pyridylimidazol‐2‐ylidine)(CO)3 . Both new species mediate the reduction of CO2 to CO following two‐electron reduction of the Mn I center, as observed with preparative scale electrolysis and verified with 13 CO2 . The two‐electron reduction of these species occurs at a single potential, rather than in two sequential steps separated by hundreds of millivolts, as is the case for previously reported MnBr(2, 2′‐bipyridine)(CO)3 . Catalytic current enhancement is observed at voltages similar to MnBr(2, 2′‐bipyridine)(CO)3 . Abstract : Catalytic manganese N‐heterocyclic carbene complexes have been synthesized and characterized: [MnBrL(CO)3 ] (see scheme; L= N ‐methyl‐ N ′‐2‐pyridylbenzimidazol‐2‐ylidine or N ‐methyl‐ N ′‐2‐pyridylimidazol‐2‐ylidine). Both species mediate the reduction of CO2 to CO following two‐electron reduction of the Mn I center at a single potential, as observed with preparative scale electrolysis and verified with 13 CO2 .