Intermediate-spin iron(III) octaethyltetraazaporphyrinates with weakly co-ordinating anions: synthesis, characterization and crystal structure

The metathesis reaction of AgZ(Z = ClO4–, PF6–, SbF6– or CF3CO2–) with chloroiron(III) 2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetraazaporphyrinate chloride, Fe(oetap)Cl, in tetrahydrofuran or toluene gave the Fe(oetap)Z derivatives in approximately 70% yield. The complexes are air-stable solids but decompose in solution to [Fe(oetap)]2 O (Z = ClO4– or CF3CO2–) or Fe(oetap)F (Z = PF6– or SbF6–). They have been characterized by variable-temperature magnetic susceptibility measurements and Mössbauer, UV/VIS, IR and ESR spectroscopies. In addition, Fe(oetap)ClO4 has been structurally characterized by single-crystal X-ray diffraction. All of the complexes are intermediate-spin (S=) based on their magnetic properties and Mössbauer and ESR spectra.