Novel microporous europium and terbium silicates

The synthesis and structural characterization of the first examples of microporous europium(III) and terbium(III) silicates (Na(4)K(2)X(2)Si(16)O(38). 10H(2)O, X = Eu, Tb) are reported. The structure of these solids was solved by powder X-ray diffraction ab initio (direct) methods and further characterized by chemical analysis (EDS). thermogravimetric analysis (TGA), scanning electron microscopy (SEM), (23)Na and (29)Si magic-angle spinning (MAS) NMR, and luminescence spectroscopy. Both materials display interesting photoluminescence properties and present potential for applications in optoelectronics. This work illustrates the possibility of combining in a given silicate microporosity and optical activity.