Multifunctional Magnetic Materials Obtained by Insertion of Spin-Crossover FeIII Complexes into Chiral 3D Bimetallic Oxalate-Based Ferromagnets

The syntheses, structures, and magnetic properties of compounds of formula [FeIII(5-Clsal2-trien)][MnIICrIII(ox)3]·0.5(CH3NO2) (1), [FeIII(5-Brsal2-trien)][MnIICrIII(ox)3] (2), and [InIII(5-Clsal2-trien)][MnIICrIII(ox)3] (3) are reported. The structure of the three compounds, which crystallize in the orthorhombic P212121 chiral space group, presents a 3D chiral anionic network formed by MnII and CrIII ions linked through oxalate ligands with inserted [FeIII(5-Clsal2-trien)]+, [FeIII(5-Brsal2-trien)]+, and [InIII(5-Clsal2-trien)]+ cations. The magnetic properties indicate that the three compounds undergo long-range ferromagnetic ordering at ca. 5 K. On the other hand, the inserted FeIII cations undergo a partial spin crossover in the case of 1 and 2.