Multi-component bi-layers featuring [1-octyl-2,3-dimethylimidazolium ∩ p-sulfonatocalix[4]arene] supermolecules

Multi-component solid state structures containing 1-octyl-2,3- dimethylimidazolium cations, anionic p-sulfonatocalix[4]arenes and/or large mono-phosphonium cations, as well as lanthanide metal ions are readily accessible, which have the calixarenes organised into bi-layers with gadolinium(III) coordinated between them. The imidazolium ring is confined in the calixarene cavity, essentially forming "molecular capsules" based on two calixarenes, or with the n-octyl chain penetrating the adjacent bi-layer, with the nature of the calixarene-dimethylimidazolium interplay mapped out using Hirshfeld surface analysis. The supermolecules [1-octyl-2,3- dimethylimidazolium ∩ p-sulfonatocalix[4]arene] are persistent in aqueous solutions (¹H NMR).