Isomorphous gallium substitution in the alumosilicate sodalite framework: synthesis and structural studies of chloride and bromide containing phases

摘要: In the Na 8 [T 1 T 2 O 4 ] 6 Y sodalite system (Y= Cl, Br, = Si) aluminium bearing position was successively substituted with gallium. The synthesized products represent new composition [Al 1-y Ga y SiO (0 < 1), where Al/Ga ratio is calculated from X-ray powder data Rietveld refinements. each composition, gallium concentration in framework observed lower than that initial feed. linear expansion of lattice parameters has been [AlSiO to [GaSiO increasing framework. and refined on a single crystallographic site. This result also indicates both are indistinguishable statistically distributed -sites. -O distance, therefore, offers an averaged magnitude Al/Ga-O distance which increases concentration. contrast, Si-O remains almost constant at 162.8 pm (2σ) 163.4 (3σ) for chloride bromide sodalites, respectively. average tilt (Al,Ga)O tetrahedra leads decrease six-ring window dimension as consequence incorporation simultaneous shortening Na-O Na-Cl/Br distances, content, shows direct interaction between host enclathrated guest. Additionally, tetragonal tetrahedron distortion oxygen s-hybridization discussed function two series.