High-Spin Iron(II) in the Porphyrin Plane. Structural Characterization of (meso-Tetraphenylporphinato)bis(tetrahydrofuran)iron(II)

Article abstract of DOI:10.1021/ja00527a028

The first exception to the generality that high-spin iron(II) porphyrins are five coordinate with large out-of-plane iron displacements is reported. (meso-Tetraphenylporphinato)bis(tetrahydrofuran)iron(II) is not only six coordinate but the iron atom is rigorously in the plane of the macrocycle.As a consequence of the in-plane high-spin iron(II) atom there is a large radial expansion of the porphyrinato core (Fe-N 2.504 (2) and 2.060 (2) Angstroem).Crystal data: a 11.354 (3) Angstroem, b = 11.804 (3) Angstroem, c = 9.688 (3) Angstroem, α = 103.92 (2) <*>, β = 115.91 (3) <*>, γ = 102.38 (2) <*>, space group P1, Z = 1.The Fe-O distance is long, 2.351 (3) Angstroem.Moessbauer data (4.2-195 K) are reported.At 4.2 K ΔE = -2.76 mm s^-1 and δ = 0.96 mm s^-1, typical of high-spin iron(II).