Non-covalent interactions promoting assembly of 8-bromo-irisolidone-3′-sulfonate and metal(II) (M = copper, zinc, ferrum, nickel, magnesium, cadmium)

Sodium 8-bromo-5,7-dihydroxyl-4′,6-dimethoxylisoflavone-3′-sulfonate (NaX, X = C17H12O6BrSO3−) was synthesized with irisolidone as a leading compound, which was characterized by elemental analysis, 1H NMR and IR spectra. The self-assembly of X with metal(II) (M = Co, Zn, Fe, Ni, Mg, Cd) lead to the formation of six compounds, [M(H2O)6(X)2]·H2O (1–6). Single-crystal X-ray diffraction results of 1–6 revealed that they were isomorphous and the introduction of Br atom and –SO3− group to 5,7-dihydroxyl-4′,6-dimethoxylisoflavone facilitated the collaboration of electrostatic interaction, hydrogen bonding, π⋯π stacking interaction and the rare Br⋯π interaction, leading to three-dimensional supramolecular architectures.