Synthesis and Magnetic Properties of New Mono- and Binuclear Iron Complexes with Salicyloylhydrazono Dithiolane Ligand

We report here experimental evidence for the formation in the solid state of a new binuclear FeIII2(μ-OMe)2(HL)4 complex (H2L is 2-salicyloylhydrazono-1,3-dithiolane). The isostructural MnIII2(μ-OMe)2(HL)4 complex has provided the strongest ferromagnetic interaction value (J ≈ 20 cm−1) between MnIII ions to date. The new iron binuclear compound presented in this study shows antiferromagnetic intramolecular coupling, which agrees with the theoretical study that we previously proposed. During our synthetic work, we also observed an unexpected spontaneous reduction of the new FeIII(HL)2Cl,S complex to the new FeII(H2L)2Cl2 high-spin mononuclear complex. This process has been checked by cyclo-voltammetry as well as pseudosteady voltammetry.