Mononuclear and binuclear iron(III) complexes incorporating N4O3 coordinating heptadentate ligand: Synthesis, structure and magnetic properties

The N4O3 coordinating heptadentate ligand afforded the mononuclear [FeIII(HL)][BPh4] (1) and binuclear [Fe2IIIL(OAc)2][BPh4] (2) complexes. In complex 1, the ligand binds in a trianionic N2O3 fashion whereas in the case of 2 the ligand binds in the trianionic N4O3 form in which the iron ions are held together by μ-phenoxo and bis μ-acetato bridges. Complex 2 shows an intramolecular weak antiferromagnetic interaction. Gas phase geometry optimizations have been performed using density functional theory without any symmetry constraints.