Fe(TpivPP)(NO2)2]−: What is the Nitrite Orientation?

We have prepared a new crystalline derivative of [Fe(TpivPP)(NO2)(2)](-) with the [K(222)](+) cation. The newly determined structure of the anion resolves an ambiguity about the relative orientation of the two axial nitrite ligands which were found in a previous structure determination with a different cation. The two NO2- ligands are found to have a relative perpendicular orientation with Fe-N(NO2) distances of 1.974 (6) angstrom and 1.994 (6) angstrom. The average Fe-N-p distance in the low-spin six-coordinate iron(III) porphyrinate derivative is 1.987 (3) angstrom.