title: DFT and CASPT2 analysis of polymetallic uranium nitride and oxide complexes: how theory can help when X-ray analysis is inadequate.
abstract: Recent studies of organouranium chemistry have provided unusual pairs of similar polymetallic molecules containing (N)(3-) and (O)(2-) ligands, namely [(C(5)Me(5))U(mu-I)(2)](3)(mu(3)-N), 1, and [(C(5)Me(5))U(mu-I)(2)](3)(mu(3)-O), 2, and chair and boat conformations of [(C(5)Me(5))(2)U(mu-N)U(mu-N(3))(C(5)Me(5))(2)](4), 3. These compounds were analyzed by density functional theory and multiconfigurational quantum chemical studies to differentiate nitride versus oxide in molecules for which the crystallographic data were not definitive and to provide insight into the electronic structure and unique chemical bonding of these polymetallic compounds. Calculations were also performed on [(C(5)Me(5))(2)UN(3)(mu-N(3))](3), 4, and [(C(6)F(5))(3)BNU(N[Me]Ph)(3)], 5, for comparison with 1 and 3. On the basis of these results, the complex, [(C(5)Me(5))U(mu(3)-E)](8), 6, for which only low-quality X-ray crystallographic data are available, was analyzed to predict if E is nitride or oxide.
authors: Department of Physical Chemistry, University of Geneva, 30 Quai Ernest Ansermet, CH-1211 Geneva, Switzerland.
authors: Tanya K
authors: TK
authors: Todorova
authors: Laura
authors: L
authors: Gagliardi
authors: Justin R
authors: JR
authors: Walensky
authors: Kevin A
authors: KA
authors: Miller
authors: William J
authors: WJ
authors: Evans
mesh_terms: D018360:Crystallography, X-Ray; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D009942:Organometallic Compounds / Q000032:analysis*; D010087:Oxides / Q000737:chemistry*; D011108:Polymers / Q000032:analysis*; D011789:Quantum Theory; D017974:Uranium Compounds / Q000737:chemistry*
chemical_list: D009942:Organometallic Compounds; D010087:Oxides; D011108:Polymers; D017974:Uranium Compounds