Synthesis, Structure, and Optical Properties of BiCu2(TeO3)(SO4)(OH)3

The hetero-bimetallic polyanionic compound BiCu 2 (TeO 3 )(SO 4 )(OH) 3 was synthesized using hydrothermal techniques. Single-crystal X-ray diffraction analysis revealed that title compound crystallizes in the monoclinic space group P 2 1 / n (No. 14) with lattice parameters a = 9.5513(15), b = 6.3022(10), c = 13.955(2) Å, β = 102.845(3)°, and Z = 4. The structure of title compound is a three-dimensional tunnel framework consisting of edge-sharing two-dimensional [Cu 3 O 10 ] 14– layers linked by BiO 8 bicapped trigonal prisms, TeO 3 2– trigonal pyramids and SO 4 2– tetrahedra. Along [010], each Cu(1)O 6 octahedron shares two edges with adjacent Cu(1)O 6 units to form infinite one-dimensional zigzag chains, which are connected by double inverted Cu(2)O 6 octahedral units via edge sharing (O9 ··· O8). The suitability of crystal for optical applications was investigated by UV/Vis/NIR spectroscopy. Raman and FTIR spectra were used to confirm the presence of various functional groups such as TeO 3 2– , SO 4 2– , OH – in the crystals.