Assembly of Supramolecular Compounds with Water-Soluble Calix[4]arenes

Abstract

Three new copper compounds, Cu2[C12H8N2]2[C28H20S4O16][H2O]11.9 (1), Cu2[C12H8N2]3[C28H20S4O16][H2O]5 (2), and Cu2[C12H8N2]4[C24H12S8O16][H2O]10.5 (3), were hydrothermally synthesized and structurally determined by X-ray diffraction and TG-DTA analyses. Interestingly, Compounds 1 and 2 were synthesized in a one-pot reaction. Complexes 1 and 3 contain capsule units, which are further assembled into three-dimensional (3-D) architectures with α-Po-related topology by π−π stacking and/or hydrogen-bonding interactions. In compound 2, the zigzag chains are bridged into a 2-D 63 or 44 net by π−π stacking interactions, which are stacked further into a 3-D supramolecular topology by hydrogen-bonding interactions. It is obvious that the weak intramolecular/intermolecular interactions play an important role in the formation of supramolecular networks, especially in linking low-dimensional entities into high-dimensional supramolecular frameworks. In these complexes (together with two previous compounds we prepared at room temperature), p-sulfonatocalix[4]arene (C4AS) and p-sulfonatothiacalix[4]arene (TC4AS) ligands assuming cone shape bond to the copper cations in different ways which facilitate the formation of different topologies. Compounds 1−3 exhibit blue emission in the solid state at room temperature and their thermal properties are examined