| Institution: | 1. Department of Chemistry, Minnesota Supercomputing Institute and Chemical Theory Center, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN, 55455-0431 USA
These authors contributed equally to this work.;2. Department of Chemistry, Minnesota Supercomputing Institute and Chemical Theory Center, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN, 55455-0431 USA;3. Department of Civil & Environmental Engineering & Earth Sciences, University of Notre Dame, 301 Stinson-Remick Hall, Notre Dame, IN, 46556 USA |
| Abstract: | We report the synthesis and characterization of K4{PuCl2(NO3)3]2(μ2-O)}⋅H2O, which contains the first known μ2-oxo bridge between two PuIV metal centers. Adding to its uniqueness is the Pu−(μ2-O) bond length of 2.04 Å, which is the shortest of other analogous compounds. The Pu−(μ2-O)−Pu bridge is characterized by the mixing of s-, d-, and p-orbitals from Pu with the p-orbitals of O; the 5f-orbitals do not participate in bonding. Natural bond orbital analysis indicates that Pu and O interact through one 3c-2e σPu-O-Pu and two 3c-2e πPu-O-Pu bonding orbitals and that the electron density is highly polarized on the μ2-O. Bond topology properties analysis indicates that the Pu−(μ2-O) bond shares both ionic and covalent character. Quantum mechanical calculations also show that the dimer has multiconfigurational ground states, where the nonet, septet, quintet, triplet, and singlet are close in energy. This work demonstrates the interplay between experimental and computational efforts that is required to understand the chemical bonding of Pu compounds. |
