Crystal structure of silver carbonate iodide Ag10(CO3)3I4

Abstract

The title silver carbonate iodide, Ag₁₀(CO₃)₃I₄, deca-silver(I) tris-(carbonate) tetra-iodide, was recently reported as a precursor of the new superionic conductor Ag₁₇(CO₃)₃I₁₁. Ag₁₀(CO₃)₃I₄, was prepared by heating a stoichiometric powder mixture of AgI and Ag₂CO₃ at 430 K. A single-crystal suitable for X-ray diffraction analysis was obtained by slow cooling of a melt with an AgI-rich composition down from 453 K. Ag₁₀(CO₃)₃I₄ exhibits a layered crystal structure packed along [10], in which Ag atoms are inter-calated between the layers of hexa-gonally close-packed I atoms, and CO₃ groups. Up to now, Cs₃Pb₂(CO₃)₃I is the only other compound containing carbonate groups and iodide ions registered in the Inorganic Crystal Structure Database.

Keywords: crystal structure; layered structure; silver carbonate iodide.