DIVERGENT APPLICATIONS OF FREE BASE CORROLES AND MANGANESE(III) CORROLES

Abstract

Corroles are non-natural aromatic tetra-pyrrolic systems, often kept in mind as contracted porphyrin systems. Corroles have received widespread attention especially in the past 20 years. Nobel Laureate Dorothy C. Hodkin reported the first X-ray crystal structure of free base corrole. Free base corroles generally exists in three forms- A3, A2B (cis and trans) and ABC corroles. The present thesis encircles around one such free base form viz. trans-A2B corrole and its manganese corroles and (oxo)manganese corroles. The thesis has been divided into five chapters. The literature survey including several reported applications of corrole are summarized as an introduction in Chapter 1. Scope and objectives of the research work discussed in Chapter 2 of this thesis. In Chpater 3, synthesis of free base trans-A2B corroles, and its manganese(III) corroles, (oxo) manganese(V) corroles and fully characterized by the UV-visible, NMR, Mass spectroscopy. Kinetics of self-decay and oxygen transfer reaction to thioanisole using ozonolysis of manganese(III) corroles, electrochemistry and calculated the HOMO-LUMO gap of manganese(III) corroles by DFT studies. The electron releasing and withdrawing group attached on phenyl group at C10 position of corrole, which affect the rate constant of reactivity of 1-MnV (O) to 5-MnV (O) corroles. In Chapter 4, series of four free base trans-A2B corroles (where A = para nitrophenyl, and B = 2,3,4,5,6-pentafluorophenyl, 2,6-difluoro, 2,6-dichloro and 2,6- dibromophenyl group) have been synthesised and fully characterized by the UV-visible, NMR and mass spectrometry. These free base trans-A2B corroles were tested for the sensing ability towards Hg2+ ion. The LoD for these corroles are comparable to reported sensors for Hg2+. All these four A2B corroles exhibit different fluorescence quenching due to the electronic effect of the phenyl group at C10 position, which has a different halogen atom at 2,6 position of the phenyl ring. Chapter 5 discuss the conclusion and future scope of the work.