Tris(thio-cyanato-κN)tris-(triphenyl-phosphine oxide-κO)europium(III)-(nitrato-κ(2) O,O')bis-(thio-cyanato-κN)tris-(triphenyl-phosphine oxide-κO)europium(III) (1/1).

The title co-crystal, [Eu(NCS)3(C18H15OP)3][Eu(NCS)2(NO3)(C18H15OP)3], contains two distinct neutral complexes. Each complex has threefold symmetry about its central Eu(3+) ion. As a result, the nitrate-containing mol-ecule contains disorder of its bidentate nitrate and two N-bound thio-cyanate anions, while the [Eu(NCS)3(OPPh3)3] complex is fully ordered. There is a weak π-π stacking inter-action between the phenyl rings of the two mol-ecules [centroid-centroid distance = 4.138 (4) Å].

Tris(thio-cyanato-κN)tris-(triphenyl-phosphine oxide-κO)terbium(III).

The title compound, [Tb(NCS)3(C18H15OP)3], contains a six-coordinate Tb(II) cation surrounded by three O-bound triphenyl-phosphine oxide ligands and three N-bound thio-cyanate ligands, each in a fac arrangement. There are two crystallographically unique Tb(III) atoms in the asymmetric unit. One Tb(III) atom resides on a threefold rotation axis, while the other has no imposed crystallographic symmetry. The thio-cyanate ligands are bound through N atoms, illustrating the hard-hard bonding principles of metal complex chemistry.

(1S*,2R*,3S*,4R*,5R*)-5-Tetra-decyloxy-methyl-7-oxabicyclo-[2.2.1]heptane-2,3-dicarb-oxy-lic anhydride.

In the title compound, C23H38O5, the oxabicyclo-[2.2.1]heptane-2,3-dicarb-oxy-lic anhydride unit has a normal geometry and the tetra-decoxymethyl side chain is fully extended. In the crystal, mol-ecules are linked head-to-head by C-H⋯O hydrogen bonds, forming two-dimensional networks propagating along the a and c-axis directions.