Confinement of dimeric sulfuric acid in a self-assembled molecular capsule: [(H2SO4)2⊂(calix[5]arenesulfonic acid)2]

Abstract

Self-assembled molecular capsules are formed on crystallisation of calix[5]arenesulfonic acid resulting from treating calix[5]arene with sulfuric acid; the calix[5]arenesulfonic acid molecules dimerise via hydrogen bonding through the sulfonic acid groups, shrouding two hydrogen-bonded sulfuric acid molecules as the supermolecule [(H₂SO₄)₂}⊂{(calix[5]arenesulfonic acid)₂].