Constructing multicomponent materials involving inclusion of mono- and bis-imidazolium cations in gadolinium(III)-p-sulfonatocalix[5]arene coordination networks

p-Sulfonatocalix[5]arene forms host-guest complexes in the solid state with hydroxyl-functionalized imidazolium and bis-imidazolium cations, also involving gadolinium(III) ions which form a coordination polymer through the sulfonate groups of the calixarene. The interplay of the components have been investigated using Hirshfeld surface analysis, with the nature of the species in aqueous solution in the absence of the paramagnetic lanthanide ions studied using ¹H NMR and modeled using molecular simulations.