Dinitrosyliron complexes

Scheme 14 Oxygen activation and transfer by dinitrosyliron complexes [35]...

Hung MC, Tsai MC et al (2006) Transformation and structural discrimination between the neutral Fe(NO)2 dinitrosyliron complexes (DNICs) and the anionic/cationic Fe(NO)2 DNICs. Inorg Chem 45 6041-6047... 

Tsai ML, Liaw WF (2006) Neutral Fe(NO)2 dinitrosyliron complex (DNIC)[ (SCgH4-o-NHCOPh)(Im)Fe(NO)2] (Im = Imidazole) interconversion among the anionic/neutral Fe(NO)2 DNICs and Roussin s red ester. Inorg Chem 45 6583-6585... 

Toledo JC Jr, Bosworth CA et al (2008) Nitric oxide-induced conversion of cellular chelat-able iron into macromolecule-bound paramagnetic dinitrosyliron complexes. J Biol Chem 283 28926-28933... 

Hickok JR, Sahni S et al (2011) Dinitrosyliron complexes are the most abundant nitric oxide-derived cellular adduct biological parameters of assembly and disappearance. Free Radic Biol Med 51 1558-1566... 

Li L, Reginato N et al (2003) The synthesis and structural characterization of linear and macrocyclic bis(dinitrosyliron) complexes supported by bis(phosphine) bridging ligands. J Can Chem 81 468 75... 

For example, the dinitrosyliron(O) complex can be formed cathodically. This complex is able to catalyze the cyclodimerization of conjugated dienes (Scheme 8) 259,260) in case of 1,3-butadiene, 20000 turnovers are obtained per hour with... 

Scheme 8. Electro-generated dinitrosyliron(O) complex as catalyst for the cyclodimerization of conjugated dienes...

In addition to hemoproteins, the other major metabolically active pool of intracellular iron is the nonheme iron-sulfur proteins see Iron-Sulfur Proteins), which function primarily as electron carriers, most especially in the mitochondrial electron transfer chain. In vitro treatment with NO has been shown to result in conversion of the iron in these clusters into dinitrosyliron thiol complexes ((RS-)2pe(NO)2). As described in more detail below, these complexes exhibit a characteristic EPR signal, which has been observed in both NO-producing activated macrophages and their tumor cell targets, suggesting that such complexes may also be formed in vivo. 

The coordination number of the metal atom is influenced by the way in which electron-donating groups satisfy the rare-gas rule. Thus, 36-electron species exist for iron with coordination numbers of four (dicarbonyl-dinitrosyliron), five (pentacarbonyliron), and six (diiodotetracarbonyliron). Of course, the configuration, bonding, and modes of reaction are influenced by the coordination number of the central atom in a complex. 

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