1. Molecular Topology Directed Crystalline Architectures
Kraig A. Wheeler, Department of Chemistry, Eastern Illinois University
The manner in which chemical compounds recognize each other has far reaching importance to the development of functional materials. Since material property is closely linked to the alignment of the fundamental building blocks, it is not surprising that considerable effort has focused on the manipulation of these components. Unlike the vast majority of investigations that seek to control organization by use of functional group associations (e.g., hydrogen bonds), our approach utilizes the control feature of molecular topology to engineer molecular arrays. Conceptually, the self-assembly of molecules based on topological influences could result in a host of supramolecular architectures; however, in practice, molecular organization is often limited to energetically favorable closest-packed centrosymmetric arrangements. We have successfully exploited these known structural tendencies by preparing sets of isosteric compounds of opposite handedness that form predictable assemblies. One such example is given below where the molecular patterns of association mimic centrosymmetric alignment. Other notable outcomes from these studies include:
crystallographic evidence of the recognition
profile of molecular shape
construction of predictable noncentrosymmetric
molecular arrays
identification of isosteric chemical functions
evidence of the specificity and transferability
of molecular shape