DFT and TDDFT Study of the Reaction Pathway for Double Intramolecular C–H Activation and Functionalization by Iron, Cobalt, and Nickel–Nitridyl Complexes

Previous work was successful in synthesizing a nickel amine, [CztBu(PyriPr)(NH2-PyriPr)], by double C-H activation and functionalization via irradiating a disphenoidal Ni(II) azido complex, [CztBu(PyriPr)2NiN3]. The present work seeks to expand upon the earlier research and to substitute the metal with iron or cobalt. Density functional theory (DFT)-B3LYP/6-31+G(d') and APFD/Def2TZVP-was used to simulate the generation of an intermediate with significant nitridyl radical character after the loss of N2 from the starting azido complex. DFT and time-dependent density functional theory (TDDFT) were also used to propose a detailed pathway comprised of intermediates of low, intermediate, or high spin multiplicity and photogenerated excited states for the reaction of the azido complex, [CztBu(PyriPr)2MN3], to form the amine complex [CztBu(PyriPr)M(NH2-PyriPr)], M = Co, Ni, or Fe.