Supramolecular Structure of Cocrystallized Catechol and Hexamine

School of Chemistry, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima
â—‹Kadsada Sala Kenneth J. Haller

Computers and computational algorithms have increased in power, and consequently X-ray crystallography has been able to provide precise three-dimensional structures of more and more complex materials. This has opened two related new frontiers in solid state materials research on molecular compounds: one, supramolecular structure, deriving from the chemistry of noncovalent interactions (weak bonding interactions), and two, cocrystallization studies, allowing detailed examination of weak interactions between different molecular species in the condensed phase. These studies have become important in pharmaceutical chemistry where they allow study of potential drug interactions that may help to tailor drug molecules to fight specific diseases and may have applications in drug manufacturing. The current work reports the preparation of the 2:1 cocrystal of catechol (1,2-benzenediol) and hexamine (hexamethylenetetraamine), and the characterization of the resulting supramolecular material by single crystal X-ray analysis. The structure consists of one-dimensional chains of alternating catechol and hexamine molecules utilizing all the strong hydrogen bond donors of the catechol molecules and all the strong hydrogen bond acceptors of the hexamine molecules. Interactions between chains are by weaker noncovalent interactions. Details of the supramolecular structure will be discussed.