Cluster lanthanide chalcogenide clusters

Chaleogenide clusters Various lanthanide chalcogenide clusters Molecular minerals or monodisperse Riman et al. (2005)... 

Apart from Eu3+ and Tb3+, few studies have been reported on optical properties of lanthanide ions doped in ZnS nanociystals. Bol et al. (2002) attempted to incorporate Er3"1" in ZnS nanociystal by ion implantation. They annealed the sample at a temperature up to 800 °C to restore the crystal structure around Er3"1", but no Er3"1" luminescence was observed. Schmidt et al. (1998) employed a new synthesis strategy to incorporate up to 20 at% Er3"1" into ZnS (1.5-2 nm) cluster solutions which were stabilized by (aminopropyl)triethoxysilane (AMEO). Ethanolic AMEO-stabilized Er ZnS clusters in solutions fluoresce 200 times stronger at 1540 nm than that of ethanolic AMEO-Er complexes. This is explained by the very low phonon energies in ZnS QDs, and indicates that Er3+ ions are trapped inside chalcogenide clusters. However the exact position of Er3+ in ZnS clusters remains unknown. Further spectroscopic and structural analyses are required in order to obtain more detailed information. 

The only relevant Group 3 polynuclear complex, [Y8(/i4—0)(/i3—OH)i2(/r—Se4)4Cl2(DMF)i0] 6DMF is prepared from YC13 and polyselenide in DMF. It has an octanuclear core, supported by oxo, hydroxo, and tetraselenido bridges with no Y—Y bonds. No Sc or actinide chalcogenide clusters are known. Lanthanide/selenido clusters have recently been isolated.14... 

FIGURE 65 Common structural types of lanthanide chalcogenolate and chalcogenide clusters with nuclearity ranging from six to eight (redrawn after Li et al., 2006a). 

---