Syntheses, crystal structures, and optical properties of Pb6B3O10X (X=F, Cl, Br)

Abstract

A series of lead-containing halogen oxyborates, Pb6B3O10X (X=F, Cl, Br), have been grown by high-temperature solution method and their crystal structures were determined by single-crystal X-ray diffraction. They are isostructural and crystallize in the space group Pbcm of the orthorhombic crystal system. The crystal structures are dominated by one-dimensional ∞[(Pb4O)(BO3)3] “Zig-Zag”-chains, while the remaining Pb atoms and X (X=F, Cl, Br) atoms are filled to balance the charge. Compared with the previously reported compound Pb4O(BO3)2 (the molecular formula Pb4O(BO3)2 can be regarded as Pb6B3O10.5) with the space group Aba2, the structures of Pb6B3O10X (X=F, Cl, Br) are completely different from that of Pb4O(BO3)2. IR spectroscopy, UV–vis-NIR diffuse reflectance spectroscopy, thermal analysis, and theoretical calculations were also performed on the reported materials.