| Part A. A series of fluoroalkyl and alkyl 2,5-dichlorobenzoates were synthesized for future aryl chloride polymerization and to examine their supercritical solvent solubility. The fluorinated alkyl 2,5-dichlorobenzoates investigated in this study is highly soluble in CO2 at modest conditions. The solubility of the hydrocarbon alkyl 2,5-dichlorobenzoates decreases significantly as the alkyl chain length increases. Alkyl and fluoroalkyl ester substituted poly(p-phenylene)s (PPP) were synthesized by aryl halide coupling using a nickel catalyst and zinc. The solubilities of the alkyl and fluoroalkyl PPPs were studied in supercritical solvents. The propyl, butyl, pentafluoropropyl, and heptafluorobutyl ester substituted PPPs were not soluble in sc-ethane, sc-propane, sc-butane, or SC-CO2 at high pressures and high temperatures. The pentyl, hexyl, and octyl ester substituted PPPs were soluble in sc-ethane, sc-propane, and sc-butane. A series of polymer analogues with H-H and T-T connectivities were synthesized in the form of dimers. The dimers included octyl and tridecafluorooctyl ester moieties. The dimers were synthesized because the polymer 1H NMR showed regioirregularities in the polymer backbone.; A polymer study was initiated to attempt to increase the regioregularity in the aryl chloride coupling of alkyl and fluoroalkyl 2,5-dichlorobenzoates. The study was completed by varying the ligand (dppf, dppp, PPh3, or PPh3/bpy,) in the coupling reaction, using the hexyl, octyl, nonafluorohexyl, and tridecafluorooctyl 2,5-dichlorobenzoates. A completely regioregular polymer was not formed in the varying ligand study, therefore the regioregularity can not be generated from the nickel catalyst alone. The supercritical solubility of the biphenyl 2,3'-dicarboxylic acid dioctyl ester showed a ∼400 bar higher maximum pressure than the biphenyl-2,2'-dicarboxylic acid dioctyl ester. The biphenyl-2,3 '-dicarboxylic acid di-tridecafluorooctyl ester showed a ∼50 bar higher maximum pressure than the biphenyl-2,2'-dicarboxylic acid di-tridecafluorooctyl ester. The T-T dimers displayed higher solubility than the H-H due to the ability of the T-T dimers to have a planar conformation.; Part B. An azobenzene monomer with methoxy and hexyloxy substitutents were synthesized by a diazotination reaction of 3-bromo-4-methoxy phenol and 4-bromo aniline, and then alkylated with hexyliodide. The polymer was synthesized in a palladium-catalyzed reaction to yield the first conjugated organic polymer that contains an azo linkage in the backbone. The polymer exhibited excellent third-order nonlinear properties in THF. (Abstract shortened by UMI.)... |
