[O2Pb3]2(BO3)I: a new lead borate iodide with 1∞[O2Pb3] double chains

Abstract

A new lead borate iodide, [O₂Pb₃]₂(BO₃)I, has been successfully synthesized by a facile hydrothermal reaction. It exhibits an infinite one-dimensional (1D) ¹_∞[O₂Pb₃] double chain which is constructed from OPb₄ oxygen-centered tetrahedra. The ¹_∞[O₂Pb₃] double chains are further bridged by BO₃ units via sharing oxygen atoms to form two-dimensional (2D) ²_∞[(O₂Pb₃)₂(BO₃)] layers with the I⁻ ions situated in the spaces between the layers. First principles calculations indicate that [O₂Pb₃]₂(BO₃)I exhibits a birefringence of about 0.072@1064 nm which originates from the synergistic contributions of the Pb–O/I and BO₃ units. The IR, UV-vis-NIR and EDS results, as well as TG-DSC curves were also discussed in detail.