F. Turias, M. Solà, L. Falivene, L. Cavallo, A. Poater
Structural Chemistry February Volume 27, Issue 1, 409-417, (2016)
Iron catalyst,
Copper catalyst,
Heme,
Nitrite,
Nitric oxide,
Cytochrome c oxidase
The present computational study complements the recent experimental
efforts by Karlin and coworkers to describe the interconversion of
nitrite to nitric oxide by means of an iron porphyrin complex together
with a Cu chemical system, i.e., the iron(II) complex (F8TPP)FeII [F8TPP = tetrakis(2,6-difluorophenyl)porphyrinate(2−)] and a preformed copper(II)–nitrito complex [(tmpa)CuII(NO2)][B(C6F5)4] [tmpa = tris(2-pyridylmethyl)amine], being the latter an oxidized species of [(tmpa)CuI(MeCN)]+. By DFT calculations, we unravel how the reduction of nitrite to nitric oxide takes place through a μ-oxo heme-FeIII–O–CuII complex, following a mimetic path as in the cytochrome c
oxidase. Mayer bond order (MBO) and energy decomposition analyses are
used to analyze the bonding strength of such nitro derivatives to either
copper or iron.