Part I. Study of transition metal complexes with 3-nitrogen donor ligands. Part II. Applications of cobalt metalloradicals in controlled radical polymerization

In the first part of the study, a series of 3-nitrogen donor ligands were synthesized and the chemistry of their metal complexes was investigated.; Dipyridocarbazole (DPC) and 2,5 (di-alpha-pyridyl)pyrrole (PDP) were prepared and their Rh, Pd and Pt complexes were studied. The investigation shows that the ligands can coordinate in either tridentate or bidentate fashion. The flexibility difference between the two ligands produces different structural and reactivity features.; Tri(pyrazolyl)borate derivatives with mesityl groups gives copper complex, Cu-TpMs,H a tetrahedral structure that promotes the Cu(I) oxidation state. A series of di-immine ligands provide copper complexes a square planar geometry that favors the Cu(II) oxidation state. Both types of copper complexes successfully catalyzed Kharasch reaction, but failed to control the atom transfer radical polymerization (ATRP) reaction due to the instability of the ligand or the inappropriate equilibrium constant.; The second part of the study concentrates on the study of the functions of the cobalt-centered metalloradical in radical polymerization.; The low spin paramagnetic, non-macrocyclic Co(II) species with strong field ligand cyanide and chelate ligand bipyridine were synthesized and characterized. The catalyst has the ability to control the molecular weight of the polymer product and produce the polymer with olefin end group functionality despite the side reaction between the complex and solvent causes the loss of the active species during the reaction.; Sulfonated derivatives of tetraphenyl porphyrin and tetraanisyl porphyrin were synthesized with the tunable solubility in a large range of organic solvents and facile separability. The cobalt complexes of those ligands show effective catalytic chain transfer behavior.; Living radical polymerization mediated by Co(II) metalloradicals was studied in both organic and aqueous media. A new method using organic radical sources was developed to utilize cobalt porphyrin catalyst system more conveniently. A rate enhancement effect was observed with the presence of excess radicals. The low polydispersity homopolymers and the block copolymers of acrylates were produced in relatively short period of time using bulky cobalt porphyrin complex (TMP)Co. The fast reaction also allows the less bulky cobalt porphyrin catalyst, such as (TAP)Co, to be used because shorter reaction time reduces the probability of chain termination events.