NO2(-) activation and reduction to NO by a nonheme Fe(NO2)2 complex.

The selective reduction of nitrite (NO2(-)) to nitric oxide (NO) is a fundamentally important chemical transformation related to environmental remediation of NOx and mammalian blood flow. We report the synthesis and characterization of two nonheme Fe complexes, [Fe(LN4(Im))(MeCN)2](BF4)2 (1(MeCN)) and [Fe(LN4(Im))(NO2)2] (2), geared toward understanding the NO2(-) to NO conversion. Complex 2 represents the first structurally characterized Fe(II) complex with two axial NO2(-) ligands that functions as a nitrite reduction catalyst.