Anions in hydrophobic environments: liquid-liquid extraction of sulfate and chloride, and membrane transport of chloride

The transport of an anion across a lipid bilayer or the extraction of an anion into organic solution requires the stabilization of a charged species in a hydrophobic environment. Due to the similar energetic barriers of both processes, liquid-liquid extraction can potentially be used as a model for membrane transport. Carrier species that can efficiently extract anions from aqueous solutions into solvents such as chloroform, can potentially be utilized to facilitate the diffusion of those anions across a lipid bilayer or cell membrane. The research presented here explores the relationship between liquid-liquid extraction and membrane transport behavior. Chapter 1 presents an introduction to the equilibria reactions that are involved in extraction, the structure of lipid bilayers and a description of liposome models of cell membranes. Chapter 2 details the partitioning analysis of sulfate using radiotracers. Chapter 3 explores the chloride extraction behavior of several pyrrole-based molecules using radiotracer analysis. Chapter 4 details the extensive studies of chloride transport across lipid bilayers using liposome model membranes.