STRUCTURE OF SEMICONDUCTOR CLUSTERS INCORPORATED INTO ZEOLITE X AND SHABASITE. Yu.I.Smolin, Yu.F.Shepelev A.E.Lapshin and E.A.Vasilyeva, Institute of Silicate Chemistry of Russian Academy of Science, St.-Petersburg, Russia.
The determination of structure of semiconductor clusters incorporated into zeolites using X-ray single crystal diffraction method is discussed. Previously crystal structures of the hydrated and dehydrated forms of Cd and Pb exchanged NaX zeolite were determined. For dehydrated forms data collection was carried out at high temperature. The cycle of crystal structure determinations was carried out on crystals with incorporated CdS clasters, which were obtained by treatment of the zeolite by vapour of H2S or by repeated exposure of CdX zeolite to the solution of Na2S with intermediate exchange Na for Cd. Both hydrated and dehydrated forms were investigated. It was shown that CdS clusters occupied positions in supercages of the X-zeolite. The geometry of these clusters are described. We have tried to obtaine PbI2 clusters in X zeolite by different methods. The satisfactory results were obtained only by treatment of dehydrated form of the NaX zeolite by PbI2 vapour and by exposure of NaX crystals to supersaturated water solution of PbI2. The hydrated and dehydrated forms of X zeolite with incorporated PbI2 clusters are described. The crystal structure of shabazite-like zeolite with Se atoms which were injected into crystal from vapour, was determined. The Se atoms form 6-membered rings in the shabasite cages. Crystal data for some compounds:
1. h-PbX2 Fd3, a=25.15(1), 386 F(hkl), R=0.049, Rw=0.053
2. d-PbX2 Fd3, a=25.05(1), 189 F(hkl), R=0.048, Rw=0.053
3. h-PbI2 Fd3, a=25.05(1), 235 F(hkl), R- 0.052, Rw=0.060
5. [CdX +CdS] Fd3, a= 24.84(1), 715 F(hkl), R=0.057, Rw=0.062
6. Se-shabasite R-3m, a=9.376(3), [[alpha]]=93.56(5)deg., 182 F(hkl), R=0.075, Rw=0.084.