Reactivity and kinetics of epoxide/CO₂ coupling catalyzed by zinc(II) phenoxides and chromium(III) salens /
The development of selective and efficient homogeneous catalysts for the coupling of epoxides and CO₂ to form polycarbonates or cyclic carbonates has become an ever-increasing topic of industrial and academic research. While the current method for industrial polycarbonate synthesis (condensation of...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
2004.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=790266711&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | The development of selective and efficient homogeneous catalysts for the coupling of epoxides and CO₂ to form polycarbonates or cyclic carbonates has become an ever-increasing topic of industrial and academic research. While the current method for industrial polycarbonate synthesis (condensation of phosgene and Bisphenol A) is in no immediate danger of being replaced, the increasing interest in environmentally benign alternatives to hazardous industrial processes may eventually compel polymer manufacturers to consider the epoxide/CO₂ route as an economically viable option. Our research with this system began a decade ago after the discovery of the first homogeneous organometallic complexes to do this type of chemistry, the zinc bisphenoxides. In the intervening years, catalyst design has moved toward more elaborate ligand architectures (pyrazoylborates, porphyrins, salicylaldimines, etc.) and earlier transition metals. The recent success of the chromium salens has shown that there are possibilities outside the classical zinc-based systems. In conjunction with these efforts, kinetic studies have assisted in understanding the mechanism associated with a particular catalytic cycle, and often have helped guide development of the subsequent generations of catalyst development. Indeed, mechanistic studies have shown that the simplistic initial models of catalyst behavior are generally wrong with the actual behavior being far more complex. This report will detail catalyst design and mechanistic studies involving the classical zinc bisphenoxides as well as metallosalens, currently the most studied system in the area of epoxide/CO₂ coupling reactions. Herein, I will describe how detailed reactivity and mechanistic studies have helped push forward the group's mission of finding an optimum catalyst for the formation of polycarbonates from epoxides and carbon dioxide. |
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| Item Description: | Vita. "Major Subject: Chemistry". |
| Physical Description: | xiii, 201 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references (leaves 158-161). |