Synthesis, crystal structure and optical properties of the first bromine-containing iodate: Pb2IO3Br3

The single crystal of Pb 2 IO 3 Br 3 was successfully synthesized by the hydrothermal method , which is the first case of bromine-containing iodate. The polycrystalline powder of the compound was synthesized and its purity was characterized by X-ray single crystal diffraction. Pb 2 IO 3 Br 3 crystallized in the space group P 1 ( — ) (No. 2). In the structure of Pb 2 IO 3 Br 3 , the isolated [IO 3 ] - groups are in a reverse arrangement to fill in the tunnels of the three-dimensional network that is composed of [PbBr n ] polyhedra. In addition, first-principle calculations have been performed to investigate the relationship between the crystal structure and the optical properties . The result indicates Pb 2 IO 3 Br 3 possesses a moderate birefringence (Δn = 0.064, λ = 1064 nm), which is mainly originated from the umbrella-like [IO 3 ] groups and the [PbOBr] polyhedra.