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 [Fe-III(5-Clsal(2)-trien)][(MnCrIII)-Cr-II(ox)(3)] center dot 0.5(CH3NO2) (1), [Fe-III(5-Brsal(2)-trien)][(MnCrIII)-Cr-II(ox)(3)] (2), and [In-III(5-Clsal(2)-trien)][(MnCrIII)-Cr-II(ox)(3)] (3) are reported. The structure of the three compounds, which crystallize in the orthorhombic P2(1)2(1)2(1) chiral space group, presents a 3D chiral anionic network formed by Mn-II and Cr-III ions linked through oxalate ligands with inserted [Fe-III(5-Clsal(2)-trien)](+), [Fe-III(5-Brsal(2)-trien)](+), and [In-III(5-Clsal(2)-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 Fe-III cations undergo a partial spin crossover in the case of 1 and 2.