Bi6(SeO3)3O5Br2: A new bismuth oxo-selenite bromide

A new bismuth oxo-selenite bromide Bi6(SeO3)3O5Br2 was synthesized and structurally characterized. The crystal structure belongs to the triclinic system (space group P1̄, Z=2, a=7.1253(7) Å, b=10.972(1) Å, c=12.117(1) Å, α=67.765(7)°, β=82.188(8)°, γ=78.445(7)°) and is unrelated to those of other known oxo-selenite halides. It can be considered as an open framework composed of BiOx or BiOyBrz polyhedrons forming channels running along [1 0 0] direction which contain the selenium atoms in pyramidal shape oxygen coordination (SeO3E). The spectroscopic properties and thermal stability were studied. The new compound is stable up to 400 °C.