Dibarium zirconium tetraoxalate trihydrate.

A new mixed barium zirconium oxalate, triaquatetra-mu-oxalato-dibarium(II)zirconium(IV), Ba(2)Zr(C(2)O(4))(4).3H(2)O or [Ba(2)Zr(C(2)O(4))(4)(H(2)O)(3)](n), has been synthesized. The complex is built from eightfold-coordinated Zr atoms and eleven- and sixfold-coordinated Ba atoms, linked by oxalate groups.

Modification of calix[4]arenes with CMPO-functions at the wide rim. Synthesis, solution behavior, and separation of actinides from lanthanides.

Two calix[4]arene tetraethers (Y = C5H11, C14H29) bearing on their wide rim four -N(Me)-CO-CH2-P(O)Ph2 residues were synthesized for the first time. Their ability to extract lanthanides and actinides from an acidic aqueous phase to organic phases (CH2Cl2, NPHE) was studied. In comparison to the corresponding -NH-analogs, they are less efficient extractants, the selectivity for the light over the heavy lanthanides is less pronounced, while there is still an interesting selectivity of Am3+ over Eu3+.

KZn(HP(2)O(7)) x 2H(2)O and KMn(HP(2)O(7)) x -2H(2)O: acidpyrophosphate metallates(II) with layer structures.

The crystal structures of the isomorphous title compounds, namely potassium zinc hydrogen pyrophosphate dihydrate and potassium manganese hydrogen pyrophosphate dihydrate, consist of acidic pyrophosphate-metallate(II) layers joined by K(+) ions and hydrogen-bridging bonds. The Zn(2+)/Mn(2+) ions are octahedrally surrounded by four pyrophosphate O atoms and by two water molecules. The (HP(2)O(7))(3-) anions exhibit eclipsed conformations.

2-(2-Oxoimidazolidinyl)ethyl 2-methylprop-2-enoate.

In the crystal structure of the title compound, C(9)H(14)N(2)O(3), the molecules are linked by N-H.O=C bonds into chains parallel to [001]. Large crystals are readily obtained, presumably because of the hydrogen bonds and an energetically stable conformation of the molecule.