Journal article
Cation Templating and Electronic Structure Effects in Uranyl Cage Clusters Probed by the Isolation of Peroxide-Bridged Uranyl Dimers
Inorganic chemistry, Vol.54(9), pp.4445-4455
05/04/2015
DOI: 10.1021/acs.inorgchem.5b00248
PMID: 25868048
Abstract
The self-assembly of uranyl peroxide polyhedra into a rich family of nanoscale cage clusters is thought to be favored by cation templating effects and the pliability of the intrinsically bent U-O-2-U dihedral angle. Herein, the importance of ligand and cationic effects on the U-O-2-U dihedral angle were explored by studying a family of peroxidebridged dimers of uranyl polyhedra. Four chemically distinct peroxide-bridged uranyl dirners were isolated that contain combinations of pyridine-2,6-dicarboxylate, picolinate, acetate, and oxalate as coordinating ligands. These dimers were synthesized with a variety of counterions, resulting in the crystallographic characterization of 15 different uranyl dimer compounds containing 17 symmetrically distinct dimers. Eleven of the dimers have U-O-2-U dihedral angles in the expected range from 134.0 to 156.3'; however, six have 180 U-O-2-U dihedral angles, the first time this has been observed for peroxide-bridged uranyl dimers. The influence of crystal packing, countercation linkages, and pi-pi stacking impact the dihedral angle. Density functional theory calculations indicate that the ligand does not alter the electronic structure of these systems and that the U-O-2-U bridge is highly pliable. Less than 3 kcal.morl is required to bend the U-O-2-U bridge from its minimum energy configuration to a dihedral angle of 180. These results suggest that the energetic advantage of bending the U-O-2-U dihedral angle of a peroxide-bridged uranyl dimer is at most a modest factor in favor of cage cluster formation. The role of counterions in stabilizing the formation of rings of uranyl ions, and ultimately their assembly into clusters, is at least as important as the energetic advantage of a bent U-O-2-U interaction.
Details
- Title: Subtitle
- Cation Templating and Electronic Structure Effects in Uranyl Cage Clusters Probed by the Isolation of Peroxide-Bridged Uranyl Dimers
- Creators
- Jie Qiu - University of Notre DameBess Vlaisavljevich - University of MinnesotaLaurent Jouffret - University of Notre DameKevin Nguyen - University of Notre DameJennifer E. S. Szymanowski - University of Notre DameLaura Gagliardi - University of MinnesotaPeter C. Burns - University of Notre Dame
- Resource Type
- Journal article
- Publication Details
- Inorganic chemistry, Vol.54(9), pp.4445-4455
- DOI
- 10.1021/acs.inorgchem.5b00248
- PMID
- 25868048
- NLM abbreviation
- Inorg Chem
- ISSN
- 0020-1669
- eISSN
- 1520-510X
- Publisher
- Amer Chemical Soc
- Number of pages
- 11
- Grant note
- DE-SC0001089 / Materials Science of Actinides Center, an Energy Frontier Research Center - the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences
- Language
- English
- Date published
- 05/04/2015
- Academic Unit
- Chemistry
- Record Identifier
- 9984618506202771
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