Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

Thesis (Ph.D.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (April 25, 2007) Vita. Includes bibliographical references.

Thesis (Ph. D.)--Drexel University, 2006. / Includes abstract and vita. Includes bibliographical references (leaves 125-142).

Thick composites (~ 3 mm in thickness) of polypyrrole with electrically insulating porous (polystyrene) and nonporous (polymethyl methacrylate) substrates were prepared using a two-step batch method. In the two-step method, impregnation of volatile (iodine) or nonvolatile (ferric chloride) oxidant in the substrate is followed by in-situ polymerization of pyrrole. Conductivities as high as 10-1 S/cm were obtained in this work in the case of composites of polypyrrole and porous, crosslinked polystyre. Use of the nonvolatile oxidant (ferric chloride) resulted in higher conducting polymer yield, as well as composites having a higher conductivity, thermal stability, and mechanical strength. However, the volatile oxidant (iodine) could be transported to the substrate using supercritical carbon dioxide as the solvent. As a result, partitioning of the oxidant between the solvent phase and the polymer substrate, and hence the distribution of the oxidant in the substrate, could be controlled by manipulation of the pressure. The two-step batch method in which supercritical carbon dioxide is used to facilitate transport and as a solvent for the oxidant was found to be an effective method for the production of thick composites with uniform conductivity, thermal stability, and mechanical strength. Such composites are desired in important practical applications such as rechargeable battery electrodes and electromagnetic interference shielding materials.

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Roughly focus on two major kinds of ligand (H[PNP] and [PO3]H3) my work since more than one year. One of them R[PNP]H (R=iPr, Ph), We take these two ligands reacting with a series of Cu¡BAg,by good luck ,we get seven metal complexes. Among them that quite make us pleasantly surprised is Ph [PNP ] Cu dimer have quite good luminescence characteristics under the general visible light condition of the room temperature, we are sure that this characteristic can be used in many aspects such as electrochemical divices, as sensors and biological imaging agents, and in solar conversion schemes. Nitrogen fixation catalyzed by nitrogenases is an important process in biology. Recently, we are interested in this topic, and devoted in creating new metal complexes could play as an nitrogenases. For this reson, we use a bulky ligand [PO3]H3 reacting with lots of different meals including Li¡BCo¡BSn and group IV. We report herein the synthesis, characterization of them.

Several ansa C1-symmetric cyclopentadienyl-fluorenyl metallocenes based on zirconium have been prepared with different substituents at position 3 on the cyclopentadienyl ring. Isotactic polypropylene production from these systems depends highly on the size of these substituents. Therefore, large groups such as 1-methyl-4-tbutylcyclohexyl (metallocene 6), 1-methyl-cyclohexyl (metallocene 7), 1,3,3,5- tetramethylcyclohexyl (metallocene 8), and 2,3,4-trimethyl-3-pentyl (metallocene 9) have been investigated. In combination with methylaluminoxane (MAO), they showed good activity and produced high molecular weight of isotactic polypropylene. In terms of the tacticity of the polymers, metallocene 6 made the best isotactic polypropylene with ~88% mmmm pentad content. Also, it has been found that if the size of this substituent is large as in 2,3,4-trimethyl-3-pentyl (metallocene 9), then it will block the polymerization active site which will deactivate the metallocene. New synthetic pathways for the synthesis of cyclopentadienyl-fluorenyl metallocenes based on titanium have been achieved. Anchoring these types of ligands onto titanium by following the conventional method of using TiCl4 in the metallation step has failed for the production of Me2C(3-(diphenylmethyl)-C5H3)(C13H8)TiCl2 (metallocene 12), Ph2C(C5H4)(C13H8)TiCl2 (metallocene 14), and Ph2C(C5H4)(C13H8)TiMe2 (metallocene 15); this is possibly due to the high reactivity of TiCl4. Therefore, TiCl4·2THF has been prepared and used in that step to produce these new titanocenes with good yields. A new ansa-C2-symmetric substituted bis-indenyl metallocene for isotactic polypropylene production has been successfully prepared. It is known that ansa-C2- symmetric metallocenes are good catalysts for isotactic polypropylene production, but in general, their synthesis suffers from the production of the meso Cs-stereoisomer of these catalysts, which generally produces only atactic polypropylene. Therefore, the meso stereoisomers must be removed and this is considered a loss of the material that increases the cost of the catalysts. Addition of bulky substituents on the indenyl groups as in Me2Si(5,5,8,8-tetramethyl-5,6,7,8-tetrahydrobenz(f)indenyl)2ZrCl2 (metallocene 5) has prevented the meso stereoisomer production. 5/MAO produces isotactic polypropylene with up to ~80% mmmm pentad content.

Thesis (Ph. D.)--Lehigh University, 2000. / Includes bibliographical references and vita.