Multifunctional magnetic materials obtained by insertion of spin-crossover Fe(III) complexes into chiral 3D bimetallic oxalate-based ferromagnets.

The syntheses, structures, and magnetic properties of compounds of formula [Fe(III)(5-Clsal(2)-trien)][Mn(II)Cr(III)(ox)(3)]·0.5(CH(3)NO(2)) (1), [Fe(III)(5-Brsal(2)-trien)][Mn(II)Cr(III)(ox)(3)] (2), and [In(III)(5-Clsal(2)-trien)][Mn(II)Cr(III)(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.