Electrochemistry and Spectroelectrochemistry of Sapphyrins, Open-chain Pentapyrroles, Cobalt Corroles and Cobalt Dipyrrin-bisphenols

For decades, pyrrolic complexes have attracted enormous scientific attention in various fields because of the potential applications in medicine and energy storage. In this thesis, about 31 pyrrolic compounds are studied, focusing on their spectroscopic and electrochemical properties along with characterizations by various other methods. The general introduction for the investigated pentapyrolic, tetrapyrrolic and dipyrolic complexes (Chapter 1), as well as the used experimental methods (Chapter 2), are given prior to the data and discussions. Firstly, the spectral properties, protonation reactions, and electrochemistry of open-chain pentapyrroles and sapphyrins with various meso-tetraaryl substituents are discussed (Chapter 3 and 4) along with the protonation-initiated conversion of pentapyrroles to sapphyrins upon oxidation. The second part (Chapters 5, 6 and 7) is dedicated to a series of studies on electrochemistry and spectroelectrochemistry for the cobalt corroles axially ligated with bis(pyridine), mono(DMSO) and bis(ammonia). The last part (Chapter 8) presents the ligand noninnocence in cobalt dipyrrin-bisphenols as to their electrochemistry and spectroscopic properties in nonaqueous media. The potentials for each electrode reaction for all investigated pyrrolic complexes were measured by cyclic voltammetry and the electron-transfer mechanisms evaluated by analysis of the electrochemical data combined with UV−visible spectra of the neutral, electroreduced, and electroxidized forms of the investigated pyrrolic compounds.