Unique guest inclusion within multi-component, extended-cavity resorcin[4]arenes

Co-crystals involving C-methylcalix[4]resorcinarene 1 and substituted pyridines obtained from MeNO2–benzene and MeCN–benzene yields multi-component complexes 1·4(4-picoline)·MeNO2 2 and 1·4(1,10-phenanthroline)·MeCN·benzene 3 in which the cavity of 1 is extended by four pyridines supramolecularly and the included solvent serves as a guest.