Double inclusion of ferrocene within a doubly interpenetrated three-dimensional framework based on a resorcin[4]arene

Co-crystallization of C-methylcalix[4]resorcinarene (1) and 4,4′-bipyridine (2) from ethanol in the presence of ferrocene affords single crystals of 3h·2.15 (ethanol)·0.85 (ferrocene) that consist of a doubly interpenetrated 3D hydrogen-bonded framework, 1·1.5(2) (3h). The 3D framework 3h is a supramolecular isomer of a reported 2D framework 3g and possesses box-shaped cavities that include two molecules of ferrocene as a guest.