A Nonheme, High-Spin {FeNO}8 Complex that Spontaneously Generates N2O

One-electron reduction of [Fe(NO)(N3PyS)]BF4 (1) leads to the production of the metastable nonheme {FeNO}(8) complex, [Fe(NO)(N3PyS)] (3). Complex 3 is a rare example of a high-spin (S = 1) {FeNO}(8) and is the first example, to our knowledge, of a mononuclear nonheme {FeNO}(8) species that generates N2O. A second, novel route to 3 involves addition of Piloty's acid, an HNO donor, to an Fe-II precursor. This work provides possible new insights regarding the mechanism of nitric oxide reductases.