Hexacyanometalates: Molecular Precursors for High-Spin Molecules and High-TCMolecule-Based Magnets

Hexacyanometalates [BIII(CN)6)]3- react with Lewis acids [AL]2+ or A2+ to give either oligonuclear complexes with high-spin ground states [BIII(CN-AIIL)6)]9+ or three-dimensional (3D) networks with variable Curie temperature TC. We report the magnetic properties of (i) an heptanuclenr complex [Cr(CN-Ni(tetren)6](ClO4)9 (tetren is tetraethylenepentamine) exhibiting a S = 15/2 ground state and (ii)a series of hexacyanometalates-based magnets, with TC ranging from 9K to room temperature. We present the magnetic dichroic properties of some of the 3D materials, in the visible and in the X-ray range.