Synthesis, Structure, and Optical Properties of Cd₄S⁶⁺ Clusters Encapsulated in an Aluminate Cage

Abstract

Small, well‐ordered CdS semiconductor units are present in the aluminate sodalite 1 as indicated by a significant blue shift of the UV/VIS absorption edge relative to that of bulk (macrocrystalline) CdS. The spectroscopic properties of CdS in 1 are thus similar to those of colloidal cadmium sulfide, although the individual Cd 4 S 6+ clusters in 1 are about 2000 times smaller than the colloid particles. This confirms an interaction between encapsulated clusters in neighboring sodalite cages. Compound 1 was obtained from CdO, CdSO 4 , and Al 2 O 3 in a two‐stage process via the analogous sulfate sodalite followed by reduction with H 2 . equation image