Synthesis and characterization of the new tin borate SnB8O11(OH)4

A new tin(II) borate with the composition SnB8O11(OH)(4) was synthesized by a simple hydrothermal process. It crystallizes in the centrosymmetric monoclinic space group P2(1)/n (no. 14) with the lattice parameters a = 790.1(1), b = 1402.2(2), c = 994.8(1) pm, and beta = 90.40(5)degrees (Z = 4). The new compound SnB8O11(OH)(4) is isotypic to PbB8O11(OH)(4) and isostructural to BaB8O11(OH)(4). The borate layers are built up from fundamental building blocks (FBBs) with the composition [BaB8O11(OH)(4)](2-). Four of these FBBs form a nine-membered ring wherein the Sn2+ cations are located. These boron-oxygen layers are further connected by O-H center dot center dot center dot O hydrogen bond interactions. The characterization of SnB8O11(OH)(4) is based on single-crystal X-ray diffraction data, vibrational spectroscopy, DFT calculations, and thermoanalytical investigations including high temperature powder XRD.