Synthesis and Crystal Structure of Na4[(TiO)4(SiO4)3]·6H2O, a Rhombohedrally Distorted Sodium Titanium Silicate Pharmacosiderite Analogue

✍ Scribed by Mike S. Dadachov; William T.A. Harrison

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 342 KB
• Volume: 134
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1997.7608

✦ Synopsis

The synthesis and crystal structure of Na 4 [(TiO) 4 (SiO 4 ) 3 ] • 6H 2 O, a new hydrated sodium titanium silicate with the rhombohedrally distorted pharmacosiderite structure type, are reported. Na 4 [(TiO) 4 (SiO 4 ) 3 ] • 6H 2 O was synthesized as a powder by the low temperature hydrothermal crystallization of an alkaline titanium silicate gel prepared via a novel peroxide route. Its structure was determined and refined by the Rietveld method using X-ray powder data. The three-dimensional framework of Na 4 [(TiO) 4 (SiO 4 ) 3 ] • 6H 2 O is built up from clusters of four edge-sharing TiO 6 octahedra, connected by tetrahedrally coordinated silicon atoms (isolated SiO 4 groups). The large extraframework cages contain water molecules and are linked to each other via eight-membered rings (& &5 A s s in diameter). Two distinct Na cations are located: one in the off-center position of the eight-membered ring and another in the internal corner of cage. Crystal data: Na 4 [(TiO) 4 (SiO 4 ) 3 ] • H 2 O,