Cyanide-bridged 1D Mn(III)–Fe(III) bimetallic complexes: synthesis, crystal structure and magnetic properties

Cyanide-bridged Mn(III)–Fe(III) complexes have been synthesized in order to find new molecular materials with interesting magnetic properties. 1D complexes of trans-dicyanoferrite(III), [Mn(5-Cl-salen)Fe(bpClb)(CN)₂]·0.67MeCN·0.5H₂O (1), [Mn(5-Cl-salen)Fe(bpb)(CN)₂]·0.5H₂O·MeOH (2), [Mn(5-Br-salen)Fe(bpb)(CN)₂]·0.5H₂O·MeOH (3), and [Mn(5-Me-salen)Fe(bpb)(CN)₂]·0.5H₂O·MeOH (4) have been prepared and characterized by X-ray single-crystal structure analysis and magnetic measurements. All complexes possesses 1D chains of alternate [Mn(5-R-salen)]⁺ and [Fe(bpRb)(CN)₂]⁻ units that are linked by two trans-cyanide ligands of [Fe(bpRb)(CN)₂]⁻. Magnetic studies reveal that they exhibit overall intermetallic ferromagnetic coupling, while complex 4 shows a frequency-dependent AC magnetic susceptibility typical of a single-chain magnet.