Synthesis and structural chemistry of La18Li8Rh4MO39 (M=Ti, Mn, Ru)

Polycrystalline samples of La18Li8Rh4MO39 (M=Ti, Mn, Ru) have been prepared by a solid-state method and studied by neutron powder diffraction. They are isostructural with La18Li8Rh5O39 and adopt the cubic space group Pm3¯n with a ∼12.22 Å. Their structure consists of a La–O framework containing intersecting channels that run along 〈111〉. These channels are occupied by chains made up of alternating, face-sharing trigonal-prismatic and octahedral coordination polyhedra; there are two crystallographically distinct types of octahedral site. The prisms are occupied by Li and the transition metals are disordered over the two octahedral sites.

The substitution of Ti, Mn or Ru into La18Li8Rh5O39 results in the loss of the cation ordering seen in the parent compound.Figure optionsDownload as PowerPoint slide