A Computational DFT Study of Methane C−H and Ammine N−H Activations by Group 9 N-Pyrrolyl Complexes

Publication date: Available online 7 June 2019Source: Computational and Theoretical ChemistryAuthor(s): Bruce M. PrinceAbstractA density functional theory with solvation model density analysis of methane C−H and ammine N−H activations with Group 9 N-pyrrolyl phosphine complexes (Co, Rh, Ir) is presented. Analysis of the reaction, [{(pyr)3P}M(NH2)]q+, (where M signify Co, Rh, Ir; pyr = N−pyrrolyl and q = +1 and +3 for d8 and d6 Group 9) showed that Ir system occurs with a lower free energy barrier. The computed complexes all have reasonable C−H activation barriers, ΔG‡ ∼ 18 to 32 kcal/mol, which tracks with the electron density on the metal center of the transition state complexes. Ammine N−H activation barriers are discreetly low, which emphasize the square planar, [{(pyr)3P}M(Py)(NH3)(OCH3)], complexes are uniquely ready to aid the reaction cycle within a single step. Thus, such ligands are worthy of experimental study due to their ability of strong π-backbonding, which may meet the strong metal-to-ligand coordination demands of an acidic environment of methanol production.Graphical abstract
Source: Computational and Theoretical Chemistry - Category: Chemistry Source Type: research