A unique supramolecular sandwich structure of a tetrabromocatechol-chelated iron(III) complex: Mutual reinforcement of H-bonding and π⋯π stacking interactions in the crystal lattice

A unique supramolecular sandwich structure of a tetrabromocatecholate chelated mononuclear iron(III) complex, [H3ntb]2[Fe(Br4Cat)3](ClO4)3·4CH3OH·4H2O (1) [ntb = tris(2-benzimidazolylmethyl)amine and Br4CatH2 = tetrabromocatechol], is reported. The most interesting feature of the crystal structure of 1 is that the central [Fe(Br4Cat)3]3 − anion is sandwiched by the triply-protonated two ntb ligands in which mutual reinforcement of the π⋯π stacking and hydrogen bonding interactions play significant role to stabilize the structural motif. Electrochemical studies disclose both the noninnocent ligand and metal based redox processes.