Serendipity in the Crystallization of a Series of C-Alkylcalix[4]resorcinarenes from Alcoholic Solvents

The crystal structures of a series of C-alkylcalix[4]resorcinarenes (alkyl = methyl, propyl, butyl, pentyl, hexyl, heptyl, and undecyl), each crystallized from tert-butanol, are reported. In all seven of these structures, eight tert-butanol molecules link two resorcinarenes with 16 hydrogen bonds, thereby facilitating the formation of simple dimeric hydrogen-bonded capsules, each of which encapsulates one (disordered) tert-butanol molecule as guest. These structures are compared with, and contrasted to, those obtained from the same series of resorcinarenes recrystallized both from mixed solvents containing tert-butanol and from methanol alone.