Linking magnetic MII–[MV(CN)8] chains into 2D inorganic–organic hybrid materials

Abstract

Three isostructural 2D inorganic–organic hybrid M^II–[M^V(CN)₈]³⁻ materials with pyrazine (pyz) incorporated as a short organic linker between 3,2-chain motifs: [M^II(pyz)(DMF)₃]₂[M^II(DMF)₄][M^V(CN)₈]₂ (where M^II/M^V is Co/W in 1; Cu/W in 2; and Cu/Mo in 3), were constructed from the combinations formed in situ by M^II–pyrazine (M^II = Co, Cu) assemblies with cyanide building blocks [M^V(CN)₈]³⁻ (M^V = Mo, W). The unprecedented architecture of 1–3 reveals no crystallization solvent molecules and propagation of pyrazine bridges in a perpendicular direction, contrary to the previously reported compound [Cu^II(4,4′-bpy)(DMF)]₂[Cu^II(4,4′-bpy)(DMF)₂][W^V(CN)₈]₂·2DMF·2H₂O with 4,4′-bipyridine bridges. Magnetic studies of 1–3 reveal the presence of overall ferromagnetic interactions in the cyanido-bridged M^II–W^V pairs and weak antiferromagnetic interactions transferred through the M^II–pyz–M^II linkages.