Crystal structure of an unknown solvate of dodecakis-(µ2-alaninato-1:2κ(2) O:N,O)cerium(III)hexa-nickel(II) aqua-tris-(hydroxido-κO)tris-(nitrato-κ(2) O,O')cerate(III).

The chiral title compound, [CeNi6(C3H6NO2)12][Ce(NO3)3(OH)3(H2O)], comprises a complex heterometallic Ni/Ce cation and a homonuclear Ce anion. Both the cation and anion exhibit point group symmetry 3. with the Ce(III) atom situated on the threefold rotation axis. The cation metal core consists of six Ni(II) atoms coordinated in a slightly distorted octa-hedral N2O4 configuration by N and O atoms of 12 deprotonated l-alaninate ligands exhibiting both bridging and chelating modes. This metal-organic coordination motif encapsulates one Ce(III) atom that shows an icosa-hedral coordination by the O-donor atoms of the l-alaninate ligands, with Ce-O distances varying in the range 2.455 (5)-2.675 (3) Å. In the anion, the central Ce(III) ion is bound to three bidentate nitrate ligands, to three hydroxide ligands and to one water mol-ecule, with Ce-O distances in the range 2.6808 (19)-2.741 (2) Å. The H atoms of the coordinating water mol-ecule are disordered over three positions due to its location on a threefold rotation axis. Disorder is also observed in fragments of two l-alaninate ligands, with occupancy ratios of 0.608 (14):0.392 (14) and 0.669 (8):0.331 (8), respectively, for the two sets of sites. In the crystal, the complex cations and anions assemble through O-H⋯O and N-H⋯O hydrogen bonds into a three-dimensional network with large voids of approximately 1020 Å(3). The contributions of highly disordered ethanol and water solvent mol-ecules to the diffraction data were removed with the SQUEEZE procedure [Spek (2015 ▸). Acta Cryst. C71, 9-18]. The given chemical formula and other crystal data do not take into account the unknown amount of these solvent mol-ecules.

Relativistic density functional theory modeling of plutonium and americium higher oxide molecules.

The results of electronic structure modeling of plutonium and americium higher oxide molecules (actinide oxidation states VI through VIII) by two-component relativistic density functional theory are presented. Ground-state equilibrium molecular structures, main features of charge distributions, and energetics of AnO3, AnO4, An2On (An=Pu, Am), and PuAmOn, n = 6-8, are determined. In all cases, molecular geometries of americium and mixed plutonium-americium oxides are similar to those of the corresponding plutonium compounds, though chemical bonding in americium oxides is markedly weaker. Relatively high stability of the mixed heptoxide PuAmO7 is noticed; the Pu(VIII) and especially Am(VIII) oxides are expected to be unstable.