Mo Cation Enrichment of the Structure Chemistry of Iodates: Syntheses, Structures, and Calculations of Ba(MoO)(IO)O, Ba[(MoO)(IO)O(OH)]·2HO, and Sr[(MoO)(IO)O]·HO.

The three metal iodates Ba(MoO)(IO)O (1), Ba[(MoO)(IO)O(OH)]·2HO (2), and Sr[(MoO)(IO)O]·HO (3) have been successfully synthesized by introducing second-order Jahn-Teller distorted Mo cations by a mild hydrothermal method. Single-crystal X-ray diffraction (XRD) was used to determine the structures of the three title compounds. In compound 1, the [MoO] dimers connect with the [IO] units by sharing oxygen atoms to form two-dimensional (2D) layers that are separated by the Ba cations. For comparison, the [MoO] dimers and the [IO] units are isolated in compound 2, and they are connected by the [BaO] polyhedra forming a 3D network. For compound 3, the [MoO] polyhedra link with each other by corner and edge sharing to build 2D corrugated layers with tunnels containing isolated [IO] units. The [SrO] polyhedra link the 2D corrugated layers to form a 3D network. The infrared (IR) spectra, the ultraviolet-visible-near-infrared (UV-vis-NIR) diffuse reflectance spectra, and thermal stabilities of compounds 1 and 2 are presented. In addition, the theoretical calculations are also carried out to evaluate their band gaps and density of states.