Heteropolymetalates containing lanthanides: Solution and solid state chemistry.
Item
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Title
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Heteropolymetalates containing lanthanides: Solution and solid state chemistry.
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Identifier
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AAI3047242
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identifier
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3047242
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Creator
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Luo, Qunhui.
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Contributor
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Adviser: Lynn C. Francesconi
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Date
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2002
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Language
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English
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Publisher
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City University of New York.
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Subject
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Chemistry, Analytical | Chemistry, Inorganic
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Abstract
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The monovacant heteropolyanions, [alpha-1-P2W17O 61]10- (denoted alpha-1) and [alpha-2-P2W17O61]10- (denoted alpha-2), derived from the Wells-Dawson ion [alpha-P2W 17O61]6- by removal of a [WO] 4+ unit are known to react with lanthanide (III) ions to form complexes. In this study, these complexes have been systematically characterized in solution and solid state.;Three lanthanide (Lu, Eu and Gd) alpha-2 1:2 complexes have been crystallized and their structures solved by X-ray crystallography. The molecule structures are in good agreement with solution structure characterizations.;The solution and solid state chemistry for Ln alpha-2 1:1 complexes has been studied by 31P, 183W NMR spectroscopy, fluorescence spectroscopy and X-ray crystallography. In solid state, [Eu(alpha-2-P 2W17O61)]7-, exists as dimeric form, [Eu(H2O)3(alpha-2-P2W17O 61)]214-. In solution, the dimeric form breaks down and [Eu(alpha-2-P2W17O61)] 7- exists as monomer, [Eu(H2O)4(alpha-2-P 2W17O61)]7-. This is confirmed by 183W NMR spectrum and fluorescence lifetime measurement. Also there is equilibrium between Ln alpha-2 1:1 and Ln alpha-2 1:2 complexes in solution. The equilibrium constant is in the micromolar range.;The crystal structure of [Lu(alpha-1-P2W17O 61)]7- anion has been solved. The crystallographic results are in good agreement with the fluorescence and the 183W NMR results.;A new complex of lanthanide (alpha-1-P2W17O 61)10- has been isolated. 31P and 183W NMR spectroscopy, fluorescence lifetime measurement and the elemental analysis data indicate that the formula of this new complex is [Ln(alpha-1-P 2W17O61)2]17-.;Ternary complexes of [Ln(alpha-1-P2W17O 61)]7- with organic ligands have been observed from titration of organic ligands to [Ln(alpha-1-P2W17O 61)]7- monitored by 31P NMR. A chiral organic ligand, L-tartaric acid, was bound to the two optical isomers of [Ln(alpha-1-P 2W17O61)]7-, as revealed from 31P NMR titration to form diastereomeric pairs of Ln alpha-1-P 2W17O61 - L-tartaric acid complexes.;The protonation constants for (alpha-2-P2W17O 61)10- have been measured. Two methods have been developed to measure formation constant for Ln alpha-1 and Ln alpha-2 complexes: ligand-ligand competition method monitored by 31P NMR and metal-ligand titration monitored by Eu(III) fluorescence excitation combined with lanthanide-lanthanide competition. The results from both methods are in good accord with each other and comparable with references.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
