Synthesis, crystal structure and optical properties of the new lead fluoride borate-Pb{sub 2}BO{sub 3}F

• Published in: Journal of solid state chemistry 2011-11, Vol.184 (11)
• Main Authors: Zhao Wenwu, Graduate School of the Chinese Academy of Sciences, Beijing 100049, Pan Shilie, Han Jian, Yao Jiyong, Yang Yun, Li Junjie, Zhang Min, Zhang Lianhan, Hang Yin
• Format: Article
• Language: English
• Subjects: ATOMS; BORATES; BORON COMPOUNDS; BORON OXIDES; CHALCOGENIDES; COHERENT SCATTERING; CRYSTAL LATTICES; CRYSTAL STRUCTURE; CRYSTALS; DIFFERENTIAL THERMAL ANALYSIS; DIFFRACTION; FLUORIDES; FLUORINE COMPOUNDS; FOURIER TRANSFORMATION; HALIDES; HALOGEN COMPOUNDS; HEXAGONAL LATTICES; INFRARED SPECTRA; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; INTEGRAL TRANSFORMATIONS; LEAD COMPOUNDS; LEAD FLUORIDES; LEAD HALIDES; LEAD OXIDES; MONOCRYSTALS; OPTICAL PROPERTIES; OXIDES; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; SCATTERING; SPACE GROUPS; SPECTRA; SYMMETRY GROUPS; SYNTHESIS; TEMPERATURE RANGE; TEMPERATURE RANGE 0400-1000 K; THERMAL ANALYSIS; TRANSFORMATIONS; X-RAY DIFFRACTION
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/j.jssc.2011.08.024

A new compound, Pb{sub 2}BO{sub 3}F, has been grown by high temperature solution method from the PbO-PbF{sub 2}-B{sub 2}O{sub 3} system for the first time. The crystal structure of this compound has been identified by single crystal X-ray diffraction analysis. It crystallizes in the hexagonal system, space group P6{sub 3}/m (No. 176) with unit-cell parameters a=7.2460(3) A, c=14.5521(17) A, Z=6, V=661.69(9) A{sup 3}. Its structure was solved by the direct methods and refined to R{sub 1}=0.0163 and wR{sub 2}=0.0367. The structure of Pb{sub 2}BO{sub 3}F consists of the distorted PbO{sub 3}F{sub 2} groups and BO{sub 3} triangles, which are all symmetric with each other in the gestalt structure to the extent that the Pb{sub 2}BO{sub 3}F compound crystallizes in the symmetric space group. The powder X-ray diffraction pattern of the Pb{sub 2}BO{sub 3}F has been measured. The BO{sub 3} functional groups presented in the sample were identified by FTIR spectrum. The DTA curve of Pb{sub 2}BO{sub 3}F suggests that Pb{sub 2}BO{sub 3}F melts congruently at 448 deg. C. - Graphical Abstract: The Pb atoms are in the five coordination environments bonded to three O atoms and two F atoms to make up the distortional PbO{sub 3}F{sub 2} polyhedra. Every six PbO{sub 3}F{sub 2} polyhedra are connected by one F(1) atom to form the symmetrical structure, and then the distortion of the PbO{sub 3}F{sub 2} polyhedra is offset. Highlights: > A new compound, Pb{sub 2}BO{sub 3}F, has been grown by high temperature solution method from the PbO-PbF{sub 2}-B{sub 2}O{sub 3} system for the first time. > It crystallizes in the hexagonal system, space group P6{sub 3}/m (No. 176) with unit-cell parameters a=7.2460(3) A, c=14.5521(17) A, Z=6, V=661.69(9) A{sup 3}. > UV-vis-NIR Diffuse-Reflectance spectrum shows that its ultraviolet cutoff edge is about 288 nm. > DTA curve of Pb{sub 2}BO{sub 3}F suggests that Pb{sub 2}BO{sub 3}F melts congruently at 448 deg. C.