SYNTHESIS, CHARACTERISATIONS AND APPLICATIONS OF DIVERSE PHOSPHORUS CORROLES

Abstract

The thesis begins with the discussion of various structure-based studies of a series of well characterized phosphorus corroles. Penta-hexa coordination behaviour of ABA phosphorus corroles have been discussed thoroughly. Synthesized phosphorus corroles have been characterized using various spectroscopic techniques. NMR spectroscopic studies have been carried out in detail, which indicated that the P(V) meso-triarylcorrole conversely existed in hexacoordinate environments in coordinating solvents CH3OH, CD3OD. Whereas when in non-coordinating solvents (CH2Cl2, and CHCl3), dissociated to their pentacoordinate complexes. Possibility of the existence of hexa-coordinated geometry of P(V) corrole complexes even in non coordinating solvents, such as CH2Cl2, by substituting axial hydroxyl groups of a central P(V) atom by methyl substituted silyloxy groups and fluoride atom was also witnessed. Further, a series of nine ABA type phosphorus corrole complexes with different substituents have been synthesised and characterized by UV-visible, mass spectrometry and NMR spectroscopy. Their electrochemical studies, photophysical studies and Density Functional Theory (DFT) calculations were carried out. Further, for the application purpose carboxyphenyl substituted phosphorus corrole was synthesized by hydrolyzing the phosphorus corrole containing carboxymethyl substituent. Förster resonance energy transfer (FRET) phenomenon taking place between CdSe QDs (Quantum dots) and phosphorus corrole with the assistance of absorption, steady state and time resolved fluorescence spectroscopy have been explored. Presence of carboxyl substituent further induced the formation of an efficient QD-corrole (donor-acceptor) pair. Phosphorus corrole containing lipophilic carboxyl substituent were utilized for anticancer action on HeLa cell line and additionally was found to be a promising bioimaging tool.