INVESTIGATIONS INTO THE ROBUSTNESS OF SECONDARY AND TERTIARY ARCHITECTURE OF HYDROGEN-BONDED CRYSTALLINE TAPES

Five crystal structures of hydrogen-bonded complexes -iodophenyl)-N'-( p-cyanophenyl)-melamine.barbital, N,N'-diphenylmelamine-5,5-dimethylba rbituric acid, omophenyl)amino)-6-chloro-1,3,5-triazine-barbital, mela mine-5,5-dibromobarbituric acid, and melamine-barbituric acid) are pre sented. These particular components represent perturbations on the mol ecules that were previously used to construct crystallographic hydroge n-bonded tapes (Zerkowski, J. A.; MacDonald, J. C.; Seto, C. T.; Wierd a, D. A.; Whitesides, G. M. J. Am. Chem. Soc. 1994,116, 2382). Four of the complexes pack in the solid state as linear tapes, while the diph enylmelamine-dimethylbarbituric acid complex packs as a crinkled tape due to the closer stacking of tapes permitted by the small methyl subs tituents. The triad of hydrogen bonds that forms tapes is apparently r obust to this sort of variation, even though some of the substituents introduce noncovalent intertape interactions, such as halogen-nitrogen contacts, ionic forces, and other hydrogen bonds. The potential of su ch intertape interactions for designing crystalline architecture is di scussed.