LaMo₈O₁₄

The crystal structure of lanthanum octamolybdate contains an equal mixture of cis-edge-sharing and trans bi-face-capped octahedral Mo₈ clusters. These clusters and the O atoms, the arrangement of which derives from a closest-packing with the layer sequence ABAC..., form sheets parallel to the (bc) plane of the orthorhombic unit cell. The Mo—Mo distances range from 2.5877 (4) to 2.7780 (5) Å and from 2.5961 (5) to 2.8866 (7) Å in the trans and cis-edge-sharing isomeric clusters, respectively. The shortest Mo—Mo distance between the Mo₈ clusters within the same layer is 3.0807 (4) Å and between clusters in adjacent layers 3.6380 (5) Å. The Mo—O distances are between 2.026 (3) and 2.120 (3) Å in the trans isomer and between 1.938 (3) and 2.169 (3) Å in the cis-edge-sharing isomer. The environment of each of the two crystallographically independent La³⁺ ions consists of twelve O atoms which form a distorted cuboctahedron. The La—O distances lie between 2.593 (3) and 2.927 (3) Å and between 2.489 (3) and 3.029 (3) Å for the La1 and La2 sites, respectively.

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