Synthesis, characterization and potential applications of porphyrin analogues: secochlorin and hydrazinophyrin

Expanded porphyrins and porphyrin analogs have attracted much attention in the literature as of late. They have proposed applications in many areas such as photodynamic therapy (PDT), X-ray radiation therapy, anion binding, enzyme models, and catalysis. Therefore, new porphyrin analogs which possess the unique physical or electronic properties appropriate for these applications are desired. Chapter 1 of this dissertation provides a discussion of natural porphyrin and porphyrin derivatives, as well as a more in depth description of advances in porphyrin synthesis and syntheses of porphyrins with extended π-systems. From this introduction, the attempted synthesis of novel π-extended porphyrins is described. During this process a heterofore unavailable pigment, the free-base secochlorin was discovered. Its characterization and preparation are outlined. Functionalization and potential applications of this chlorin isomer are discussed. Chapter 2 departs from the traditional porphyrin field, and presents an introduction to the growing field of Schiff-base expanded porphryins. Experimental work in this chapter describes the synthesis and full characterization of octamethoxy hydrazinophyrin and a water-soluble analog, octaPEGhydrazinophyrin. Chapter 3 begins with an introduction to liquid crystals, then moves to discotic porphyrin liquid crystals and ends with a review of known liquid crystal sensors. The main focus of the chapter is the synthesis and characterization of the first expanded porphyrin liquid crystals and first discotic uranium containing liquid crystals. The end of each chapter contains a discussion of future directions for research and an Experimental section describing the synthesis and characterization data of all novel compounds. Lastly, the Appendix outlines the synthesis of a dipropiol pyrrole that was not incorporated into any of the previous chapters but may be of use in creating functionalized porphyrins and expanded porphyrins.