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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. |
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