Syntheses and crystal structures of four new silver(i) iodates with d0-transition metal cations

Abstract

Systematic explorations of new phases in the Ag^I-Ti^IV/V^V/Mo^VI-iodate systems led to four new quaternary silver iodates, namely, Ag₂Ti(IO₃)₆, Ag₂(VO₂)(IO₃)₃, Ag₂(V₂O₄)(IO₃)₄, and Ag₂(MoO₂)(IO₃)₄. They represent the first examples of silver iodates containing d⁰ transition metal cations. Ag₂Ti(IO₃)₆ is isostructural with K₂Ti(IO₃)₆ and its structure features a zero-dimensional (0D) [Ti(IO₃)₆]²⁻ anionic unit composed of non-distorted TiO₆ octahedron corner-sharing with six IO₃⁻ groups. Such anions are further bridged by Ag⁺ ions into a 3D network. In both Ag₂(VO₂)(IO₃)₃ and Ag₂(V₂O₄)(IO₃)₄, each vanadium(V) is octahedrally coordinated by one terminal and two bridging oxo anions as well as three iodate anions in unidentate fashion. Neighboring VO₆ octahedra form a 1D vanadium(V) oxide chain via corner-sharing oxo anions, such chains are further decorated by iodate anions in bridging or unidentate fashion. Ag₂(VO₂)(IO₃)₃ features a thick triple layer composed of two Ag(2)(VO₂)(IO₃)₂ and one Ag(1)IO₃ sheet whereas Ag₂(V₂O₄)(IO₃)₄ features a 3D network composed of 1D [(V₂O₄)(IO₃)₃]⁻ anionic chains along the c-axis that are interconnected by [Ag₄(IO₃)₂]²⁺ clusters. Ag₂(MoO₂)(IO₃)₄ is isostructural with K₂(MoO₂)(IO₃)₄ and its structure features a 3D network built from 0D [(MoO₂)(IO₃)₄]²⁻ anions further interconnected by Ag⁺ ions. Optical and luminescent property measurements as well as band structure calculations based on density functional theory (DFT) methods have also been performed.