Synthesis of water-soluble metal complexes employing 1,3,5-triaza-7-phosphaadamantane (PTA) as a ligand /
The synthesis of zero-valent metal complexes of 1,3,5-triaza-7- phosphadamantane (PTA) from M[]Cl₂ salts where M= Ni Pd and Pt in the presence of excess phosphine and water is described. The Ni derivative has also been synthesized through the treatment of Ni(COD)₂ where COD= bis-l,2-cyclooctadiene,...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1999.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=733678421&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | The synthesis of zero-valent metal complexes of 1,3,5-triaza-7- phosphadamantane (PTA) from M[]Cl₂ salts where M= Ni Pd and Pt in the presence of excess phosphine and water is described. The Ni derivative has also been synthesized through the treatment of Ni(COD)₂ where COD= bis-l,2-cyclooctadiene, with PTA in a toluene/methanol solvent mixture. Methodology for the isolation and characterization of these M⁰(PTA)₄ complexes is presented. These complexes have been characterized by ³¹P NMR and elemental analysis, as well as X-ray crystallography for the Ni and Pt derivatives. Evidence for the existence of a rare, water-soluble platinum hydride, [Pt(H)(PTA)₄][X], where X= Cl⁻, BF₄, and HCO₃⁻ in the form of ³¹P NMR and ¹⁹⁵Pt NMR is presented. Reactions of various acids with Pt(PTA)₄ have been utilized to define the plea of the metal center to be between 7.44 and 9.25. Insight into the reactivity of the Ni(PTA)₄ complex is gained through the reaction of this complex with small molecules such as CO and CN⁻. Ni(CO)[](PTA)[] derivatives have been isolated and characterized through infrared and ³¹P NMR spectroscopy. One of these derivatives, Ni(CO₂(PTA)₂, was characterized by X-ray crystallography. Reactions of Ni(PTA)₄ and CO in water were monitored to probe the lability of the phosphine ligands under aqueous conditions. Characterization of these derivatives have allowed the fit of the PTA ligand into the stet-ic and electronic parameters developed by Tolman. [] Attempts to isolate an analogous CN⁻ complex, [Ni(CN)(PTA)₃]⁻ are also described, along with the isolation and structural characterization of Ni(CN)₂(PTA)₃. Chemistry of the PTA ligand with Group 6 metals, specifically W and Mo is also described herein. Structural evidence for the trans-isomer of W(CO)₄(PTA)₂ is presented, which resulted in further investigation into the cis-, trans- isomerization of both the W(CO)₄(PTA)₂ complex and the Mo(CO)₄(PTA)₂ complex. Lastly, investigations into the coupling reaction of CO₂ and epoxides are discussed. Monitored reactions of the copolymerization of CO₂ with either propylene oxide, or cyclohexane oxide catalyzed by bis (2,6-diphenyl phenoxide) zinc were performed. The coupling of CO₂ and propylene oxide catalyzed by Ni(PTA)₄ to form propylene carbonate, the cyclic product, is also described, along with comparisons to other existing nickel phosphine catalysts. Attempts to copolymerize aziridines with CO₂ to form polyurethanes using zinc catalysts such as bis (2,6-diphenyl phenoxide) zinc are presented. |
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| Item Description: | Vita. "Major Subject: Chemistry". In title, numerals are used. |
| Physical Description: | xv, 152 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references (leaves 103-110). |