Molecular structure of an Fe(IV) species: {[Fe(TTP)](2)N}SbCl6

The molecular structure of the formal iron(IV) porphyrinate derivative, {[F e(TTP)(2)N}SbCl6 (TTP = tetratorylporphyrinate), is reported. The structura l parameters are compared to the previously reported species Fe(TPP)](2)N, in which the iron oxidation state is +3.5. Both the equatorial and axial bo nd distances in {[Fe-(TTP)](2)N}SbCl6 are slightly shortened and consistent with an increased formal charge on iron. The value for the axial Fe-N dist ance is 1.6280(7) Angstrom, and the average value of the equatorial Fe-N-p distances is 1.979(5) Angstrom. The Mossbauer isomer shift decreases upon o xidation, again consistent with an increase in formal charge. Values for th e isomer shift at room temperature are -0.13 mm/s for {[Fe(TTP)](2)N}SbCl6 and 0.04 mm/s for [Fe(TTP)](2)N. Crystal data for {[Fe(TTP)](2)N}SbCl6 are as follows: orthorhombic, space group Fddd, Z = 8, a = 23.689(2) Angstrom, b = 31.056(3) Angstrom, c = 22.7788(18) Angstrom.