Mononuclear and dinuclear complexes of manganese(iii) and Iron(iii) supported by 2-salicyloylhydrazono-1,3-dithianeligand: synthesis, characterization and magnetic properties

Abstract

The coordination chemistry of 2-salicyloylhydrazono-1,3-dithiane (H₂L) was studied with manganese and iron ions. The following complexes have been isolated as crystalline materials, and their crystal structures have been determined by single crystal X-Ray crystallography: Mn^III(acac)(HL)₂ (1) (acac = acetylacetonate), Mn^III(HL)₃·CH₂Cl₂ (2), Fe^III(HL)₃·2CHCl₃ (3), Fe^II(H₂L)₂Cl₂·2CH₃OH (4), Fe^III₂(μ-OMe)₂(HL)₄·0.5CH₃OH (5), Fe^III₂(μ-O) (HL)₄·3CH₂Cl₂ (6). All attempts to synthesize the dinuclear μ-methoxo complex [Mn^III₂(μ-OMe)₂(HL)₄] have so far failed, even when the procedure used in the case of 2-salicyloylhydrazono-1,3-dithiolane (H₂L′) ligand, which worked very efficiently, was employed. The new iron dinuclear μ-methoxo complex (5) presented in this study shows antiferromagnetic intramolecular coupling (J = −21.1 cm⁻¹), which is in agreement with the theoretical study proposed previously for its manganese analogue.