Use of iron t-diketonate complexes as catalysts in the oxidation of H₂S to S by air /
Iron []-diketonate complexes were investigated as Microfilm Inc.homogeneous catalysts for the conversion of HZS to elemental sulfur. The protonotion constants were determined potentiometrically for the following []-diketones: acetylacetone (acac), benzoylacetone (bzac), dibenzyolmethane (dbme), 1,1,...
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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=733050191&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Iron []-diketonate complexes were investigated as Microfilm Inc.homogeneous catalysts for the conversion of HZS to elemental sulfur. The protonotion constants were determined potentiometrically for the following []-diketones: acetylacetone (acac), benzoylacetone (bzac), dibenzyolmethane (dbme), 1,1,1-trifluoro-2,4-pentanedione (tfac), l-phenyl-4,4,4-trifluoro-l ,3-butanedione (bfac), and thenoyl-2,4-pentanedione (sfac). With these lights the effects of end group substitutions of these p-diketones were determined. A substitutions of these p-diketones were determined. A ethanol-25% water was employed to increase solubility of the complexes. As the dielectric constants of the solvents are lowered, the protonotion constants were found to increase. The effects of aqueous, alcoholic, and organic solvent systems on the precipitation of elemental sulfur were also studied. The binding constants of iron(II) and iron(III) with the []- diketones were determined spectrophotometrically (for several 1:1 metal chelates) and potentiometrically. Substitution of a methyl group by a phenyl group results in a small increase in basicity and a small increase in both the iron(II) and the iron(III) formation constants. The replacement by a trifluoromethyl group exhibits a large increase in acidity and a great decrease in the stability of the metal chelate complex. Proposed iron complexes with hydrated []-diketonates of bfac and sfac were characterized by IR, Uv-vis, and FAB-MS and the stability constants were determined by potentiometer. From the stability constants, the reduction potentials for the iron chelates and conditional constants for the oxidation reactions (the oxidation of HZS and the reduction of Oz) were calculated. Iron-acac, iron- bzac, and iron-tfac complexes were found to have reduction potentials useful in HDS catalysis. lron-acac was studied in aqueous, 75% ethanol-25% water, and in various N-methyl-2-pmolidone solvent systems for the oxidation of HZS. Identification of the degradation products of the chelating agents was 1 13 characterized by HPLC, H, and C NMR spectra. |
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| Item Description: | Vita. "Major Subject: Chemistry". |
| Physical Description: | xx, 153 leaves : illustrations ; 28 cm. |
| Bibliography: | Includes bibliographical references (leaves 141-149). |