Solvent control in the formation of supramolecular host–guest complexes of isoniazid with p-sulfonatocalix[4]arene

Here we demonstrate the solvent role in the cocrystallization of anti-tuberculosis drug isoniazid INH with macrocyclic host p-sulfonatocalix[4]arene C4S. The host–guest inclusion complex of INH with C4S crystallizes from aqueous solution. Altering the crystallization medium to water–cosolvent mixtures results in the formation of C4S-INH exo complexes, where the host cavity becomes occupied by a solvent molecule.