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 iron(III) complex is reported.•Cooperation of the π⋯π stacking and hydrogen bonding interactions is observed.•An unprecedented supramolecular aggregate in the metal–dioxolene chemistry.•Electrochemical studies disclose both the noninnocent ligand and metal based redox processes.

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.

Graphical abstractA unique supramolecular sandwich structure of tris(dioxolene)iron(III) complex is reported in which π⋯π stacking and hydrogen bonding interactions cooperatively play significant role to stabilize the structural motif. Electrochemical properties of the redox-noninnocent complex are also explored.Figure optionsDownload full-size imageDownload as PowerPoint slide