The role of cation–cation interactions in a neptunyl chloride hydrate and topological aspects of neptunyl structural units

The compound K4(NpO2)3Cl7(H2O)4 was synthesized by evaporation of a Np5+-bearing solution. The crystal structure was determined by single crystal X-ray diffraction and refined to R1=0.0374. The compound is triclinic, P−1, a=8.882(1) Å, b=12.082(2) Å, c=12.403(2) Å, α=65.855(2)°, β=69.604(2)°, γ=74.432(2)°, V=1126.0(3) Å3, and Z=2. The structure contains dimers of edge sharing Np5+ pentagonal bipyramids that are linked into infinite chains through cation–cation interactions with an additional Np5+ pentagonal bipyramid. The structural units are linked through bonds to interstitial K cations and by H bonding. A graphical representation for neptunyl structural units including cation–cation interactions is introduced.

The structure of K4(NpO2)3Cl7(H2O)4 contains neptunyl pentagonal bipyramids that are linked into chains through cation–cation interactions.Figure optionsDownload as PowerPoint slide