Synthesis, structural and magnetic properties of oxo-, chloroacetato-bridged tetra-nuclear iron(III) complex

► Tetra-nuclear oxo- and chloroacetato-bridged iron(III) complex, from [Fe3O]+7 core. ► The tetra-nuclear entity consists of a [Fe4(μ3-O)2]8+ “bent-butterfly” unit. ► X-ray crystallography displays C2 axis perpendicular to the central Fe2O2 rhomboid. ► Four iron(III) centers exhibits strong antiferromagnetic exchange interactions. ► FeIII atoms on body/body site suffers frustration in the spin alignment with Jbb = 0.