An eight-coordinated tantalum polyhedron in the shape of a cube with one vacant vertex is discovered for the first time in the dynamically disordered crystal structure of a tantalum fluoride double salt containing some oxygen.

Using density functional theory, the structure, stability and properties of the zeta phase in the group VB transition metal carbides are examined. It is concretely shown that this phase occurs at the composition M₃C₂ (M = Ta, Nb, V). The three systems share a crystal structure, but they exhibit differences in how the phase accommodates non-stoichometry, which has implications for their material properties.

In the title compound, the exocyclic penta­fulvene carbon atom coordinates in a staggered conformation relative to the η¹-ligands.

The crystal structure of the title compound comprises a [Ta₆I₁₂(H₂O)₆]²⁺ unit, two I⁻ counter-anions and four water mol­ecules of crystallization. The charge-assisted crystal packing is consolidated by hydrogen bonds.

Simulated X-ray diffraction patterns of shock-compressed single-crystal tantalum for polychromatic synchrotron undulator sources at different shock velocities and detection geometries are presented, along with their interpretation.

A high-flux sub-micrometre focusing system for 100 keV X-rays using multilayer focusing mirrors was constructed and evaluated at the undulator beamline BL05XU of SPring-8.

α-Agostic interactions are revealed in one of a series of pentamethylcyclopentadienyltantalum imido complexes. Reactions of these complexes with pentafluorophenol afford chemical products that are influenced by electronic and steric effects, as shown by structural analysis.

The only known isolable TaL₆ complex of Ta⁰, i.e. Ta(CNDipp)₆ (Dipp is 2,6-diiso­propyl­phen­yl), crystallizes as small amounts of the ionic salt [Ta(CNDipp)₇][Ta(CNDipp)₆] upon reduction by caesium graphite in tetrahydrofuran of the Ta^I precursor TaI(CNDipp)₆, which was also structurally characterized.

Because of the significant difference in the piezoelectric moduli between lithium niobate and lithium tantalate, variation of the piezoelectric properties in local regions of the crystal can appear. A correlation between the change in the piezoelectric properties and the composition in a mixed lithium niobate–tantalate crystal was established.

A new half-sandwich tantalum(V) dichlorido complex containing the O,N,O′-tridentate double-deprotonated 2-eth­oxy-6-{(E)-[(2-oxido­phen­yl)imino]­meth­yl}phenolate ligand was prepared, thoroughly characterized and revealed considerable in vitro cytotoxicity against the A2780 human ovarian carcinoma cell line.