Synthesis, structure, and characterization of a new one-dimensional tellurite phosphate, Ba2TeO(PO4)2

A new one-dimensional tellurite phosphate, Ba2TeO(PO4)2 has been synthesized by standard solid-state reaction techniques using BaCO3, TeO2, and (NH4)H2PO4 as reagents. The structure of Ba2TeO(PO4)2 was determined by single-crystal X-ray diffraction. Ba2TeO(PO4)2 crystallizes in the triclinic space group P  -1 (No. 2), with a=6.9461(16)Å, b=7.3970(17)Å, c=8.887(2)Å, α=76.843(4)°α=76.843(4)°, β=79.933(4)°β=79.933(4)°, γ=75.688(4)°γ=75.688(4)°, V=427.40(17)Å3, and Z=2Z=2. Ba2TeO(PO4)2 has a novel one-dimensional chain structure that is composed of PO4 tetrahedra and TeO5 polyhedra. Te4+ cations are in asymmetric coordination environments attributable to their lone pairs. The lone pairs on the Te4+ cations point in the [100] and [−100] direction and interact with the Ba2+ cations. Infrared, Raman, and UV–Vis diffuse reflectance spectroscopy, thermogravimetric analysis, and dipole moment calculations are also presented.

Ball-and-stick diagram showing one-dimensional structure of Ba2TeO(PO4)2 in the bc-plane. Note the chains run along the b-axis.Figure optionsDownload as PowerPoint slide