Hyperpolarization using Parahydrogen

Work presented in the thesis encompasses the hyperpolarization techniques, SABRE and PHIP, within the context of nuclear magnetic resonance spectroscopy. In the first instance, pyridine derivatives have been hyperpolarized using [Ir(COD)(IMe)Cl]. The effect of solvent, magnetic field, concentration, temperature, shake time, position of pyridyl ring and sterics were examined in order to optimize the hyperpolarization process for SABRE. The horizon of this study was further broadened to hyperpolarize biologically relevant molecules. The hyperpolarization studies carried out on the biological molecules ultimately provided us with an insight into the conditions necessary to optimize the hyperpolarization phenomena. Factors such as temperature shake time, pKa, concentration, exchange rate, steric hindrance around binding site were observed to contribute to the polarization transfer process and a fine interplay between these factors leads to an effective and efficient polarization transfer to the substrate under observation. Reaction of [IrCl(DMSO)3] with PPh3 in the presence of p-H2 at 298 K, yielded long-lived p-H2 enhanced hydride resonances for two new complexes. These complexes were identified as the trisubstituted triphenylphosphine product [IrCl(H)2(PPh3)3] and the disubstituted product, [IrCl(H)2PPh3)2(DMSO)] and these products were characterized by NMR spectroscopy. Furthermore, the reaction of [IrCl(DMSO)3] with pyridine led to the formation of monosubstituted complex [IrCl(H)2(py)(DMSO)2] and the SABRE effect was observed in the resonances of the free pyridine. The reaction of complex, [IrCl(DMSO)3], with amino acids yielded new dihydrido amino acid complexes.