Synthesis and anion binding studies of pyrazole and biimidazole-containing receptors

This dissertation covers two different topics within the area of diaza-containing aromatic five-membered rings: biimidazoles and pyrazoles. With the exception that both these subject matters are explored in the context of developing new anion binding agents, the background and research associated with these two topics are vastly different and will be treated as such. Chapter two, dealing with biimidazoles, focuses solely on expanded porphyrins, while chapter three discusses pyrazoles as potential macrocyclic building blocks and as diamidic-functionalized anion binders. The first chapter covers several different topics in order to put into perspective the diverse subject matter presented in this dissertation. It begins with an overview of some well-known expanded porphyrins. The synthesis, classical applications, and newer studies of the biimidazole synthetic efforts are then described. The third part of the introductory chapter covers the synthesis and applications of pyrazoles. The use of heterocycles with more than one heteroatom in the construction of expanded porphyrins is just beginning to be explored, and is the focus of chapter two. The synthesis of a novel expanded porphyrin is described and its applications are investigated. More specifically, chapter two covers the synthesis of several biimidazole dialdehydes and their condensation with three 3,3',4,4'-functionalized bis-[alpha]-free bipyrroles to form a series of novel macrocycles. The characterization of these new compounds has been investigated and is discussed in detail. Also presented are preliminary studies of their anion binding properties. Pyrazoles, the subject of chapter three, are another overlooked class of potential building blocks in the area of expanded porphyrins and molecular recognition chemistry. Pyrazoles have rarely been reported in the literature as being part of a larger molecular framework. Until this work, their anion binding potential had remained unexplored. Thus, the attempted incorporation of a pyrazole fragment into an expanded porphyrin framework is described. Second, and more significantly, the design, synthesis, and anion binding properties of a new series of diamidic pyrazoles are reported.