Synthesis, structure, and characterization of a new one-dimensional tellurite phosphate, Ba 2TeO(PO 4) 2

Abstract

A new one-dimensional tellurite phosphate, Ba 2TeO(PO 4) 2 has been synthesized by standard solid-state reaction techniques using BaCO 3, TeO 2, and (NH 4)H 2PO 4 as reagents. The structure of Ba 2TeO(PO 4) 2 was determined by single-crystal X-ray diffraction. Ba 2TeO(PO 4) 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 ) ° , β = 79.933 ( 4 ) ° , γ = 75.688 ( 4 ) ° , V = 427.40 ( 17 ) Å 3 , and Z = 2 . Ba 2TeO(PO 4) 2 has a novel one-dimensional chain structure that is composed of PO 4 tetrahedra and TeO 5 polyhedra. Te 4+ cations are in asymmetric coordination environments attributable to their lone pairs. The lone pairs on the Te 4+ cations point in the [100] and [−100] direction and interact with the Ba 2+ cations. Infrared, Raman, and UV–Vis diffuse reflectance spectroscopy, thermogravimetric analysis, and dipole moment calculations are also presented.