X-ray and neutron-diffraction studies of the crystal structures of the dicesium lithium hexacyanometallates of manganese(III) and chromium(III)

Article abstract of DOI:10.1007/BF01171024

Crystallographic examination of samples of Cs₂Li[M^III(CN)₆] (M^III=Mn, Cr), prepared by an improved route, establishes the unit cells as very closely approximating to face-centered cubic with lattice constants a=10.64(1) (M^III=Mn) and 10.75(1) A (M^III=Cr). Although a few weak non-face-centered cubic reflections and splittings were detected by powder neutron diffraction, refinement in Fm3m was as good as in primitive cubic or tetragonal space groups. Single-crystal neutron-diffraction refinements in Fm3m yield bond lengths Mn-C=1.980(5) A, Cr-C=2.03(1) A, and C-N=1.188(5) and 1.20(1) A, respectively. At 4.2 K, neutron powder data indicate the presence of further non-face-centered lines for both compounds, with contraction of unit-cell parameters to 10.55(1) and 10.67(1) A, respectively.