Date of Award
Master of Science (MS)
Department of Chemistry
Timothy D. Lash
Carbaporphyrins are porphyrin analogs where one or more pyrrole units are replaced with a carbocyclic ring. Benziporphyrins are porphyrin analogues with a 1,3-phenylene unit replacing one of the pyrrole subunits. Because of cross-conjugation, benziporphyrins are not aromatic species. However, protonation of benziporphyrins can afford some aromatic characteristics. Although the synthesis of many examples of monocarbaporphyrins have been successfully executed, no examples of porphyrinoids with pyrene subunits have been prepared. Pyrene-containing porphyrinoids, which have been named as pyreniporphyrins, are theoretically significant molecules that provide insights into the aromaticity and reactivity of porphyrinoid systems.
In this thesis, two projects were conducted to explore the synthesis, reactivity, aromaticity, and coordination chemistry of pyreniporphyrins. The first project involved the development of a synthetic route to a pyreniporphyrin. A pyrene dialdehyde was prepared and reacted with a tripyrrane using an acid-catalyzed MacDonald “3+1” condensation. The proton NMR spectrum of the pyreniporphyrin in CDCl3 demonstrated the absence of global aromatic character.
However, in the presence of acid, the corresponding dication exhibited significant diatropic properties. Pyreniporphyrin reacted with palladium(II) acetate to give an organometallic derivative. In the second project, a thiapyreniporphyrin was prepared from a pyrenitripyrrane. This intermediate condensed with a thiophene dicarbinol to afford, following an oxidation step, a tetraphenyl thiaporphyrinoid in modest yield.
Gao, Ruixiao, "Synthesis And Characterization Of Polycyclic Aromatic Hydrocarbon (pah) - Porphyrin Hybrids" (2016). Theses and Dissertations. 614.