Professor Jonathon L. Sessler, of the Department of Chemistry and Biochemistry at the University of Texas at Austin, is supported by the Organic and Macromolecular Chemistry Program for his studies of expanded porphyrins and calixpyrroles. Through the synthesis of expanded porphyrin systems, including those designed to provide three-dimensional coordination geometries to complement the planar to near-planar geometry afforded by simpler porphyrin derivatives, Professor Sessler assesses the geometric requirements of anion complexation, cation coordination, and neutral substrate binding by these systems. Related studies address the basic molecular recognition properties of two new substrate binding platforms, the calix(n(pyrroles and calix(n)pyridines. The specific interaction between ions or molecules and receptors for them represents a critical feature in countless biochemical processes. Whereas the `molecular recognition` of positively charged species (cations) has received intense scrutiny, the recognition of negatively charged molecules (anions) has developed more slowly. With the support of the Organic and Macromolecular Chemistry Program, Professor Jonathon L. Sessler, of the Department of Chemistry and Biochemistry at the University of Texas at Austin, prepares large-ring cyclic compounds designed to display specific interactions with various anions. Given their unique structural features, many of these compounds also act as binding agents for cations and neutral molecules. Through the synthesis and study of these compounds, Professor Sessler gains critical information regarding the relationship between structure and function in the binding of ions and molecules.
