Syntheses, crystal structures, and optical properties of Pb{sub 6}B{sub 3}O{sub 10}X (X=F, Cl, Br)
A series of lead-containing halogen oxyborates, Pb{sub 6}B{sub 3}O{sub 10}X (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 {sub ∞}[(Pb{sub 4}O)(BO{sub 3}){sub 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 Pb{sub 4}O(BO{sub 3}){sub 2} (the molecular formula Pb{sub 4}O(BO{sub 3}){sub 2} can be regarded as Pb{sub 6}B{sub 3}O{sub 10.5}) with the space group Aba2, the structures of Pb{sub 6}B{sub 3}O{sub 10}X (X=F, Cl, Br) are completely different from that of Pb{sub 4}O(BO{sub 3}){sub 2}. IR spectroscopy, UV–vis-NIR diffuse reflectance spectroscopy, thermal analysis, and theoretical calculations were also performed on the reported materials. Highlights: • A new family of lead-containing halogen oxyborates, Pb{sub 6}B{sub 3}O{sub 10}X (X=F, Cl, Br), have been grown by high-temperature solution method. • Owing to the introduction of X atoms into Pb{sub 4}O(BO{sub 3}){sub 2}, the structures of Pb{sub 6}B{sub 3}O{sub 10}X are completely different. • The crystal structures are dominated by one-dimensional {sub ∞}[(Pb{sub 4}O)(BO{sub 3}){sub 3}] “Zig-Zag”-chains.