DFT Investigation of C-F Bond Activation by a Low-Coordinate Cobalt(I) Complex

Publication date: Available online 24 February 2017 Source:Computational and Theoretical Chemistry Author(s): Quan Jiang, Thomas R. Cundari A low-coordinate cobalt(I) complex, LtBuCo [LtBu = bulky β-diketiminate ligand] was reported to be capable of cleaving the C-F bond in fluoroarenes. To investigate the mechanism of C-F bond activation, a simplified ligand model (LMeCo) with methyl substituents was first used as a guide before the full LtBuCo complex was calculated. DFT calculations indicate the free energy change of C-F oxidative addition is -3.9 kcal mol-1 to yield a Co(III) product. When the initial interaction of Co(I) complexes and the π-ring of PhF occurs, the free energy increases by 0.4 kcal mol-1. As a result, the formation of π-adducts is deemed to be an important mechanistic step, but is very sensitive to the steric influence of the supporting ligand substituents. The calculations indicate oxidative addition as a viable pathway for the activation of strong C-F bonds by Earth-abundant 3d metals. Graphical abstract
Source: Computational and Theoretical Chemistry - Category: Chemistry Source Type: research
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