EXPLORATION AND MECHANISTIC STUDY OF WEAKLY COORDINATING ANIONS UNDER THERMAL AND PHOTOCHEMICAL CONDITIONS FOR SELECTIVE TRANSFORMATIONS OF C-C MULTIPLE BONDS

Abstract

The underlying focus of this work has been to acknowledge the effects of anions in transition metal-based systems. In this respect, a novel family of weakly coordinating anions (imadazolylphenyl or IMP anions) in addition to traditional anions were compared under both thermal and photochemical conditions. A significant portion of this work has also been employing and analyzing computational techniques in transition metal-based systems for developing luminescent materials. In the second chapter, development of [(Ipr)Au(NCMe)]+ [IMP-H] catalytic system to deliver a mild condition for internal alkyne hydration reaction was developed. Studies on the roles of solvents, temperature, and substrate into the mechanism were accomplished through rate and kinetic isotope effect experiments. In the third chapter, a series of ion pairs in metal-based systems featuring [Ru(bipyridine)3]2+ and non-metallic systems featuring [HN(Et)3]+ were synthesized to dissect and specifically study the ion pairing vs ion coordination effects. NMR and DFT studies were performed to investigate and model those results. The Ru-based ion pairs were also employed to showcase the crucial nature of anions in light mediated E/Z isomerization reaction of an activated alkene proceeding through energy transfer pathway. In the fourth chapter, computational and photophysical studies of anionic NHC-based systems using Cu were performed. TDDFT studies to predict the energies of the singlet and triplet excited states to rationalize the luminescent properties of synthesized the complexes were attempted. In the fifth chapter, a collaboration between the Chemical Development (CD) unit of GSK at Upper Providence (PA) and Dobereiner lab (Temple University) to develop and optimize the conditions for a palladium catalyzed allylic amination reaction was undertaken. A systematic study on the roles of solvent, ligand loadings, and additives was conducted using High Throughput Experimentation, HPLC, and LCMS facilities at the GSK site.