A Nonheme Sulfur‐Ligated {FeNO} 6 Complex and Comparison with Redox‐Interconvertible {FeNO} 7 and {FeNO} 8 Analogues

A nonheme {FeNO} 6 complex, [Fe(NO)(N3PyS)] 2+ , was synthesized by reversible, one‐electron oxidation of an {FeNO} 7 analogue. This complex completes the first known series of sulfur‐ligated {FeNO} 6–8 complexes. All three {FeNO} 6–8 complexes are readily interconverted by one‐electron oxidation/reduction. A comparison of spectroscopic data (UV/Vis, NMR, IR, Mössbauer, X‐ray absorption) provides a complete picture of the electronic and structural changes that occur upon {FeNO} 6 –{FeNO} 8 interconversion. Dissociation of NO from the new {FeNO} 6 complex is shown to be controlled by solvent, temperature, and photolysis, which is rare for a sulfur‐ligated {FeNO} 6 species.