Three-component carboxylic acid-bipyridine lattice inclusion host. Supramolecular synthesis of ternary cocrystals

Abstract

Cocrystallization of 1,3,5-cyclohexanetricarboxylic acid with 4,4′-bipyridine bases of different CH2 chain lengths (n = 0, 2, 4) has afforded the ternary host framework [H3CTA·bipy- eta(gauche)·(bipy-bu)0.5] (2), sustained by O-H⋯N hydrogen bonds. Inclusion of p-dichlorobenzene in the square voids of host 2 provides the first example of a quaternary cocrystal. Crystal structures of ternary cocrystals 1-3 show that methylene chains of bipy bases are not mere inert spacer units but have a conformational and structural role in controlling the supramolecular architecture of molecular complexes with carboxylic acids. © 2005 American Chemical Society.