Interactions of HNO With Metallated Porphyrins, Corroles, and Corrines

JUAN PELEGRINO; LUCIA ÁLVAREZ; MIGUEL ANGEL MORALES VÁSQUEZ; NICOLAS NEUMAN

The Chemistry and Biology of Nitroxyl (HNO)

Elsevier

Lugar: Amsterdam; Año: 2016; p. 193 - 206

One of the main targets of NO and HNO in biological systems is heme-proteins,thus there are a wide range of structure/reactivity studies using models, i.e., metalloporphyrins (MP), mainly of iron, but also manganese, cobalt, and ruthenium. Thepreferred (almost exclusively) binding mode of NO to the metal atom is throughthe nitrogen atom. Once bound, its character ranges (formally) from that of NO1 tothat of NO2.1 In recognition of the covalent nature of the MaNO bond, Enemarkand Feltham long ago proposed using the following notation for the correspondingmetal nitrosyls: {MNO}n, where M designates the metal, and n stands for the totalnumber of electrons in the d orbital of the metal ion plus those in NO π orbitals.Its relevance relies mostly on the fact that it allows rationalization of the structure(specifically the MaNaO angle, as shown in Fig. 9.1) of a wide range of differentcomplexes.2 We will begin describing NO (as well as NO2) studies of iron porphyrins, since they are possibly the most studied systems because of theirbiological relevance as ?heme models.?