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

Abstract

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.