CDS CLUSTERS IN PORES OF ZEOLITE-X

The crystal structures of the hydrated and dehydrated forms of zeolite s involving CdS clusters are determined by X-ray diffraction. Crystals with the CdS clusters obtained by repeated exchanges in a Na2S soluti on or treatment with H2S vapor are investigated. It is found that only the CdS molecules are located in the large cavities of the CdX(Na2S) crystals. The CdX(H2S) crystals contain the [Cd20S13](14+) clusters in the large cavities. It is shown that these clusters are built up arou nd the S atoms, which are situated at the centers of the large cavitie s of zeolite and coordinated tetrahedrally by Cd atoms. These atoms ar e bound through sulfur atoms with Cd cations situated near the walls o f the cavity in the environment of the aluminosilicate framework oxyge ns.