The Mg(0001) surface in Grignard reagent formation /
The interaction of [MgBrz] and l,2-dibromoethane with polycrystalline and single crystal Mg surfaces has been studied to simulate the activation of magnesium during the Grignard reagent formation. Experimental measurements were based upon low-energy electron diffraction (LEED), Auger electron spectr...
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| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
1998.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=732843231&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | The interaction of [MgBrz] and l,2-dibromoethane with polycrystalline and single crystal Mg surfaces has been studied to simulate the activation of magnesium during the Grignard reagent formation. Experimental measurements were based upon low-energy electron diffraction (LEED), Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS). The study of the composition commercial (as-received) Mg metal indicates a surface covered by a film constituted predominantly by magnesium hydroxide and a small quantity of magnesium carbonate. These results lead to the study of the interaction of 02, H2O(g), and CO2 with Mg(0001) single-crystal surfaces. When Mg(0001) interacted with 02 (up to 100 L), an ordered MgO overlayer was formed. The interaction of Mg(0001) with water vapor yielded a disordered oxide film that contained relatively large amounts of hydroxide species. A disordered oxide film consisting primarily of carbonates was formed when Mg(0001) was exposed to CO2. Reactions of Mg(0001)-MgO(100), as received and acid-etched Mg turnings with [MgBrz] and 1,2-dibromoethane (promoters) indicate that, the activation of the Mg surface during the Grignard reagent formation is achieved by the removal of the oxide Elm. Based upon these results, a flake-off model was proposed for the activation mechanism. |
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| Item Description: | Vita. "Major Subject: Chemistry". |
| Physical Description: | xiii, 129 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references: pages 123-128 . |