Self-assembly of pentaphenol adducts: Formation of 3D network and ladder-type supramolecular structures in the solid state

Abstract

The interplay of strong and weak hydrogen bonds has been used to produce self-assembled architectures by the complexation of pentaphenol 1 with the diaza compounds such as pyrazine (pyz), 4,4′-bipyridine (bpy), trans-1,2-bis(4-pyridyl)ethylene (bpy-ethe), and 1,2-bis(4-pyridyl)ethane (bpy-etha). In all cases, the primary recognition patterns involve O-H⋯N and O-H⋯O hydrogen bonds. The crystal structure of complex 1·pyz involves ladder structures stabilized by π⋯π stacking between the benzene rings of 1 and pyz. Interpenetrating ladder architectures were observed in the crystal lattice of complex 1·bpy. A network of cyclic cavities and ladder structures dominated the solid lattice of complexes 1·bpy-ethe and 1·bpy-etha. Both complexes are isomorphous; they crystallize as dihydrates and also have the same space group, P1. In the complex 1·bpy-ethe, the existence of C-H⋯π interactions involving the double bond of the ethene moiety provides additional stabilization to the three-dimensional (3D) network structure. The formation of various supramolecular motifs from the complexes can be attributed to the 3D structure of molecule 1 and the flexibility of the linking aza molecules in the crystal lattice. © 2006 American Chemical Society.