Nitrite to nitric oxide interconversion by heme FeII complex assisted by [CuI(tmpa)]+

Abstract

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 ironA. P. thanks the Spanish MINECO for a project CTQ2014-59832-JIN and European Commission for a Career Integration Grant (CIG09-GA-2011-293900). M. S. thanks the Generalitat de Catalunya for project 2014SGR931 and ICREA Academia 2014 prize, and MINECO of Spain through project CTQ2014-54306-P. A. P. and M. S. thank EU for the FEDER fund UNGI10-4E-80

Evaporated porphyrin films as nitrogen dioxide gas sensors

“…On the other hand, DFT calculations were performed to investigate the molecular interactions between porphyrin and gas molecules by using the hybrid B3LYP/6-31(d,p) basis set, since it has provided good agreement with experimental results on porphyrin systems [12]. For this study, all systems were fully optimized and the calculations were performed with the Gaussian 09 program package.…”