31P Magic Angle Spinning NMR Spectroscopy of Paramagnetic Rare-Earth-Substituted Keggin and Wells−Dawson Solids
Paramagnetic rare-earth elements have been examined as NMR structural probes in polyoxoanionic solids, which have a variety of applications as luminescent materials that are usually disordered and therefore intractable by traditional structural methods. Thirteen Keggin and Wells−Dawson polyoxotungst...
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Published in | Journal of the American Chemical Society Vol. 130; no. 2; pp. 481 - 490 |
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Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
American Chemical Society
16.01.2008
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Subjects | |
Online Access | Get full text |
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Summary: | Paramagnetic rare-earth elements have been examined as NMR structural probes in polyoxoanionic solids, which have a variety of applications as luminescent materials that are usually disordered and therefore intractable by traditional structural methods. Thirteen Keggin and Wells−Dawson polyoxotungstates containing substitutions with lanthanides of different effective magnetic moments have been examined by 31P magic angle spinning NMR spectroscopy. The electron−nuclear dipolar interaction dominating the spinning sideband envelopes is determined by the lanthanide's magnetic moment and was found to be a sensitive probe of the nature of the polyoxoanion, of the positional isomerism, and of the ion stoichiometry. Electron−nuclear dipolar anisotropies computed based on the point−dipole approximation are generally in good agreement with the experimental results. The choice of a specific lanthanide as a structural probe can be tailored to the desired distance range between the phosphorus atoms and the paramagnetic centers to be probed. This approach is expected to be particularly useful in the paramagnetic polyoxoanionic materials lacking long-range order. |
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Bibliography: | istex:52D95929DEABFB0EF969A2AEDC1E49241ADEB110 ark:/67375/TPS-Z683VMLN-N ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 To whom the correspondence should be addressed: a) Tatyana Polenova, Department of Chemistry and Biochemistry, University of Delaware, Newark, DE19716, e-mail: tpolenov@udel.edu, Tel. (302) 831-1968, FAX (302) 831-6335; b) Lynn C. Francesconi, Department of Chemistry, Hunter College, 695 Park Avenue, New York, NY 10021, e-mail: lfrances@hunter.cuny.edu, Phone (212) 772-5353, FAX (212) 772-5332 |
ISSN: | 0002-7863 1520-5126 |
DOI: | 10.1021/ja0714585 |