Intermediate-spin iron(III) octaethyltetraazaporphyrinates with weakly coordinating 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 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)]O-2 (Z = ClO4- or CF3CO2-) or Fe(oetap)F (Z = PF6- or SbF6-). They have been characterized by variable-temperature magnetic susceptibility measurements and Mossbauer, 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 ate intermediate-spin (S = 3/2) based on their magnetic properties and Mossbauer and ESR spectra.