Bis{tris[(1H-benzimidazol-3-ium-2-yl)methyl]amine} tetraaquaocta-μ₂-chlorido-octachloridopentacadmate(II) monohydrate

The title compound, (C₂₄H₂₄N₇)₂[Cd₅Cl₁₆(H₂O)₄]·H₂O, contains a [Cd₅Cl₁₆(H₂O)₄]⁶⁻ anion, two triply protonated tris[(1H-benzimidazol-3-ium-2-yl)methyl]amine cations and one solvent water molecule. The structure of the anion is a novel chloride-bridged pentanuclear cluster. The five unique CdII centres have quite different coordination environments. Two of the central hexacoordinated CdII cations have a CdOCl₅ chromophore, in which each CdII cation is ligated by four bridging chloride ligands, one terminal chloride ligand and one water molecule, adopting a distorted octahedral environment. The third central CdII cation is octahedrally coordinated by four bridging chloride ligands and two water molecules. Finally, the two terminal CdII cations are pentacoordinated by two bridging and three terminal chloride ligands and adopt a trigonal-bipyramidal geometry. A three-dimensional supramolecular network is formed through intra- and intermolecular O-H∙∙∙O, O-H∙∙∙Cl, N-H∙∙∙Cl and N-H∙∙∙O hydrogen bonds and π-π interactions between the cations and anions.