Abstract

The crystal structures of [AdeH⁺](I₃⁻)(I₂)_5/2(H₂O) and [CytH⁺]₂(I₅⁻)₂(H₂O)₃, where Ade is adenine and Cyt cytosine, are reported. The two compounds are the first examples of supramolecular architectures assembled from protonated nucleobases and polyiodides. In [AdeH⁺](I₃⁻)(I₂)_5/2(H₂O), the mono-protonated adenine cations and water form hydrogen-bonded ribbons of nanometer width. The ribbons are embedded into a novel polyiodide matrix constructed by unusual rotaxane-like polyiodide chains. In [CytH⁺]₂(I₅⁻)₂(H₂O)₃, hydrogen-bonded cytosinium–water ribbons and polyiodide ribbons of combined branched polyiodide chains build a sheet-like structure containing alternately arranged positive and negative strips. Both architectures show good complementarity between the protonated nucleobase–water ribbons and polyioide species. The hydrogen bonds between the counter charged parts play a key role in stabilizing the associations.