Reactions of yttrium atoms in hydrocarbon matrices: electron paramagnetic resonance evidence for matrix-isolated YO and Y n (n= 5 or 7)
| Autor: | Harry Morris, Carl A. Hampson, Brynmor Mile, James A. Howard, M. Histed |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Cyclohexane
Chemistry Adamantane chemistry.chemical_element Yttrium law.invention chemistry.chemical_compound Crystallography Paramagnetism Pentagonal bipyramidal molecular geometry Unpaired electron law Physical and Theoretical Chemistry Electron paramagnetic resonance Hyperfine structure Nuclear chemistry |
| Zdroj: | Journal of the Chemical Society, Faraday Transactions. 87:3189 |
| ISSN: | 1364-5455 0956-5000 |
| DOI: | 10.1039/ft9918703189 |
| Popis: | Deposits given by condensing resistively heated yttrium metal into cyclohexane and adamantane matrices under high vacuum and at 77 K on a rotating cryostat have been examined by EPR spectroscopy. The principle paramagnetic products under these conditions are YO in at least two distinct trapping sites and yttrium clusters, Yn, where n= 5 or 7. Analysis of the yttrium hyperfine interaction for YO indicates that the unpaired electron has 60% metal 5s character with the remainder of the unpaired spin in oxygen, matrix and metal p and 4d orbitals. An yttrium cluster, Yn, is produced in adamantane that is tumbling freely or pseudorotating above 205 K and has ca. 10% unpaired spin in the Y 5s orbital with the rest pressumed to be in metal 4d orbitals. A different Y cluster is formed in cyclohexane that could be a rigid pentemer or septemer with a trigonal bipyamidal or pentagonal bipyramidal structure. It is tentatively suggested that Y5 is formed in adamantane and that Y7 is formed in cyclohexane. |
| Databáze: | OpenAIRE |
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