Engineering Void Space Enclosed within Resorcin[4]arene-Based Supramolecular Frameworks

A family of hydrogen-bonded supramolecular frameworks based on C-alkylresorcinol­[4]­arene (RsC) and 4,4′-bipyridine (bpy) type spacers are described in this article. The size and shape of the void space enclosed within these frameworks are engineered by varying the type of solvent (acetonitrile and ethanol), spacer molecules (4,4′-bipyridine (bpy), trans-1,2-bis­(4-pyridyl)­ethylene (bpe), 1,2-bis­(4-pyridyl)­acetylene (bpa)), and the conformations and/or type of RsC bowl (boat vs cone or C-methylresorcin­[4]­arene/RsC1 vs C-propylresorcin­[4]­arene/RsC3). A change in the solvent system from acetonitrile to ethanol brings about a conformational change with the RsC1 macrocycle and also results in the distinct orientation of spacer molecules around the RsC macrocycle. The predominant feature in all of the frameworks is the O–H···N intermolecular interaction between RsC building blocks and bipyridine-type spacers. The resultant solvent-filled void spaces available within frameworks can be controlled by manipulating the parameters investigated in this study.