Synthesis, structure and properties of two H-bonded supramolecular compounds based on 18-crown-6 macrocycle

Two hybrid macrocyclic-based supramolecular compounds, [(PM-NH3)·(18-crown-6)]2·[Bi2Cl8(H2O)2] (1) and [(H3O)·(18-crown-6)]2·(Sb2Cl8) (2), have been synthesized and characterized by single crystal X-ray diffraction, elemental analysis, IR, XRPD and 1H NMR (PM-NH3+=phenylmethanaminium). The macrocyclic cation, [(PM-NH3)·(18-crown-6)]+, was formed by the PM-NH3+ inserting into the 18-crown-6 through strong N–H⋯O18-crown-6 H-bonding interactions. And the [Bi2Cl8(H2O)2]2− anion clusters were presented to maintain the charge balance and result in the formation of macrocycle-based compound 1. In compound 2, the disordered H3O+ cations were embedded in the macrocyclic molecules through six strong O–H⋯O18-crown-6 H-bonds to form a macrocyclic [(H3O)·(18-crown-6)]+ cation, and the dinuclear (Sb2Cl8)2− was provided to balance the cation. Therefore, the anion clusters and macrocyclic cation assemblies were alternately stacked together to build two novel supramolecular functional compounds. In addition, the thermal analysis and luminescent properties were investigated.

► The Bi(III) centers were chelated through two μ2-Cl donors to form the [Bi2Cl8(H2O)2]2− unit.
► The macrocycle-based assemblies were formed by the cations inserting into the crown ether.
► Two novel crown ether-based supramolecular structures have been synthesized.