Part I. Reactivity and equilibrium thermodynamic studies of rhodium porphyrins in water. Part II. Radical interchange polymerization (RIP): Living radical polymerization mediated by organo-cobalt complexes

Current interest in converting organometallic processes from organic to aqueous media motivated this research to evaluate the scope of organometallic reactions and thermodynamic parameters for rhodium porphyrin species in water. Rhodium porphyrins activate an array of substrate such as H2, CO, and CH4 in hydrocarbon media to form rhodium hydride, rhodium formyl and rhodium methyl complexes. This thesis was to determine if comparable substrate reactions occur in aqueous solution and focused on reactivity and equilibrium thermodynamic studies of water soluble rhodium porphyrin species in the +1, +2, and +3 oxidation states including rhodium hydride, rhodium hydroxide, and rhodium (II) dimer complexes with H2, CO, aldehydes, ketones, and olefins. Water soluble porphyrin rhodium complexes including rhodium tetra (p-sulfonato phenyl) porphyrin ((TSPP)Rh) and rhodium tetra (3, 5-sulfonato mesityl) porphyrin ((TMPS)Rh) derivative applied in this research were prepared by sulfonation of tetra phenyl porphyrin (H2TPP) and tetra mesityl porphyrin (H 2TMP). Aqueous solutions of rhodium (III) tetra (p-sulfonatophenyl) porphyrin ((TSPP)Rb(III)) complexes react with dihydrogen to produce equilibrium distributions between six rhodium species including rhodium hydride ([(TSPP)Rh-D(D 2O)]-4), rhodium(I) ([(TSPP)RhI(D 2O)]-5), and rhodium (II) dimer ([(TSPP)RhII(D 2O)]2-8) complexes. Equilibrium thermodynamic studies (298 K) for this system establish the quantitative relationships that define the distribution of species in aqueous solution as a function of the dihydrogen and hydrogen ion concentrations through direct measurement of five equilibrium constants along with dissociation energies of D2O and dihydrogen in water. Each of these types of rhodium porphyrin species including Rh(I), Rh(II), Rb(III), Rh-H, and Rh-OH functions as a precursor for a group of organometallic substrate reactions. The second part of this dissertation describes a new developed living radical polymerization method, referred to as radical interchange polymerization (RIP). Low-polydispersity homopolymers and block copolymers of acrylates are produced at relatively fast rates when an azo radical source generates organic radicals and organo-cobalt complexes guide the polymerization through a radical interchange polymerization (RIP). (Abstract shortened by UMI.