ChemInform Abstract: Symmetry versus Minimal Pentagonal Adjacencies in Uranium-Based Polyoxometalate Fullerene Topologies

Department of Civil Engineering and Geological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA.
Angewandte Chemie International Edition (Impact Factor: 11.26). 06/2009; 48(15):2737-40. DOI: 10.1002/anie.200805870
Source: PubMed


C U soon: Clusters containing 60, 44, and 36 uranyl peroxide hydroxide polyhedra (see picture) adopt fullerene topologies of maximum symmetry. The largest of these, denoted U60, is topologically identical to C(60) with no pentagonal adjacencies and the highest possible symmetry. U44 adopts the topology with maximum symmetry rather than that with the lowest number of pentagonal adjacencies.

Download full-text


Available from: Peter C Burns,
1 Follower
65 Reads
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Laser ablation of solid UO(3) or (NH(4))(2)U(2)O(7) yielded in the gas phase molecular uranium oxide anions with compositions ranging from [UO(n)](-) (n = 2-4) to [U(14)O(n)](-) (n = 32-35), as detected by Fourier transform ion cyclotron resonance mass spectrometry. The cluster series [U(x)O(3x)](-) for x < or = 6 and various [U(x)O(3x-y)](-), in which y increased with increasing x, could be identified. A few anions with H atoms were also present, and their abundance increased when hydrated UO(3) was used in place of anhydrous UO(3). Collision-induced dissociation experiments with some of the lower m/z cluster anions supported extended structures in which neutral UO(3) constitutes the building block. Cationic uranium oxide clusters [U(x)O(n)](+) (x = 2-9; n = 3-24) could also be produced and are briefly discussed. Common trends in the O/U ratios for both negative and positive clusters could be unveiled.
    Inorganic Chemistry 05/2009; 48(12):5055-7. DOI:10.1021/ic9003998 · 4.76 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Bowl (U(16)) and crown-shaped clusters (U(20R) and U(24R)) containing 16, 20, and 24 uranyl peroxide polyhedra self-assemble in alkaline aqueous solution under ambient conditions. Structural analyses of crystallized clusters provided details of their topologies. Each contains uranyl hexagonal bipyramids in which two cis edges are peroxide, with a third edge defined by two OH groups, as well as hexagonal bipyramids in which three edges are peroxide. These are the first open uranyl peroxide clusters reported, and they join a growing family of complex cluster topologies based on uranium that hold promise for nanoscale control of chemistry in nuclear energy cycles.
    Inorganic Chemistry 10/2009; 48(23):10907-9. DOI:10.1021/ic9020355 · 4.76 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Uranyl peroxide polyhedra are known to self-assemble into complex closed clusters with fullerene and other topologies containing as many as 60 polyhedra. Here clusters containing 20 uranyl pentagonal triperoxides have been isolated and characterized that assume the smallest possible fullerene topology consisting only of 12 pentagons. Oxalate has been used to crystallize fragments of larger uranyl peroxide clusters, and these fragments and other known structures indicate that the U-O(2)-U dihedral angle is inherently bent. Such bending is thought to be essential in directing the self-assembly of uranyl peroxide polyhedra into closed clusters.
    Journal of the American Chemical Society 11/2009; 131(46):16648-9. DOI:10.1021/ja907837u · 12.11 Impact Factor
Show more