“Liquid-like” type (COO−)2(H2O)10 anion water clusters in three-dimensional supramolecular structure of cucurbit[6]uril

Abstract

The three-dimensional (3D) supramolecular network structure of the guest 1,1′-(hexane-1,6-diyl)dipyridinium-4-carboxylate inner salt (HBPC) and the host cucurbit[6]uril (CB[6]) is self-assembled through an intricate array of hydrogen-bonding interactions involving the contributions of two-dimensional (2D) infinite network (COO⁻)₂(H₂O)₁₀ anion water clusters and (H₂O)₂ water clusters. These water clusters are notably have the liquid-like water characteristics in the solid and are reversibly dehydrated and rehydrated, while the pseudorotaxane retains its integrity in the process, and is stable up to 390 °C.