Electrocatalytic CO 2 reduction is demonstrated for the Mn and Re tricarbonyl complexes, [M(Me 2 OQN)(CO) 3 (CH 3 CN)] (M = Mn or Re) containing the 5,7-dimethyl-8-oxyquinolate (Me 2 OQN - ) ligand. In comparison to the related 2,2′-bipyridyl (bpy) reference complexes, [M(bpy)(CO) 3 (CH 3 CN)] + (M = Mn or Re), the Me 2 OQN - -based precatalysts exhibit an onset of catalytic current with the input of one less equivalent of electrons. This behavior is attributed to the formal Me 2 OQN (•/-) redox couple which contributes toward each catalytic cycle in tandem with the formal Mn (I/0) and Re (I/0) redox couples. In addition to computational support for synergistic metal-ligand redox cooperativity, electrochemistry (cyclic voltammetry and controlled potential electrolysis), spectroelectrochemistry (FTIR and EPR), and pulse radiolysis coupled with time-resolved infrared spectroscopy (PR-TRIR) provide structural insight into the electronic properties of the one-electron- and two-electron-reduced species..
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry