Abstract
The synthesis of a new nonheme iron NO binding complex, [Fe(II)(CH(3)CN)(N3Py(2Ph)SEtCN)](BF(4))(2) (1), is reported. Complex 1, which contains two sterically encumbering phenyl substituents, exhibits a high-spin (hs) Fe(II) (S = 2) ground state in contrast to the S = 0 ground state for unsubstituted [Fe(II)(CH(3)CN)(N3PySEtCN)(BF(4))(2). Reaction of 1 with NO((g)) in CH(3)CN yields an {FeNO}(7) (S = (3)/(2)) complex 2, which slowly decays at 25 °C with loss of NO(•) to regenerate 1. One-electron reduction of 2 with Cr(C(6)H(6))(2) at -40 °C yields the metastable, S = 1 {FeNO}(8) complex 3. The nitrosyl moieties in thioether-ligated 2 and 3 are significantly less activated than in thiolate-ligated [Fe(NO)(N3PyS)](+/0), a structurally analogous pair of hs {FeNO}(7/8) complexes. Calculations reveal that reduction of 2 is iron-centered, which may be a general property of hs {FeNO}(7/8) complexes.