Molecular nanoparticles of cerium dioxide: structure-directing effect of halide ions.

The use of halide ions in the synthesis of Ce/O clusters diverts the reaction to two halide-containing products: Cl- gives a new Ce-20 nuclearity with both a high 1 : 1 Ce3+ : Ce4+ ratio and a high percentage of (100) facet coverage, whereas F- gives a known Ce-6 nuclearity. Both products include bridging halide ions and are thus the first confirmation of non-oxo (OH-/O2-) anion incorporation onto the Ce/O cluster core.