One pot synthesis and crystal structure of aluminosilicate mixed chloro-iodo sodalite

Abstract

The crystal structure of different compositions of aluminosilicate mixed chloride and iodide sodalites was studied. The sodalites have been characterized by X-ray powder diffraction using Reitveld refinement in the space group P $\bar 4$ 3n. FT-IR spectroscopy shows the successful enclathration of chloride and iodide anions in the β-cages of sodalite. Different sodalites are prepared under low temperature hydrothermal conditions in which zeolite A is used as starting material with variation of concentration of sodium chloride and iodide. The products obtained were washed with deionized water and dried overnight at 100°C. The increase in concentration of iodide shows that the Al-O-Si angle and distances in Na₈[AlSiO₄]Cl_2−x I _x sodalite (0< x ≤ 2) are modified considerably. X-ray diffraction study clearly shows variation in unit cell from 8.9241 to 8.9910Å with increase in concentration of sodium iodide. IR study also shows pronounced shift in frequency with concentration of iodide. Amount of chloride and bromide was determined by potentiometry. SEM study shows cubic crystal morphology.