Ba1.09Pb0.91Be2(BO3)2F2: The First Pb-Containing Beryllium Borate Fluoride with Trigonal Prismatic PbO6 and 2D [Be3B3O6F3]∞ Layers

Ruixin Guo; Shu Guo; Mingjun Xia; Lijuan Liu; Minjuan Li; Sangen Zhao; Xiaoyang Wang

doi:10.1021/acs.inorgchem.2c04122

Ba_1.09Pb_0.91Be₂(BO₃)₂F₂: The First Pb-Containing Beryllium Borate Fluoride with Trigonal Prismatic PbO₆ and 2D [Be₃B₃O₆F₃]_∞ Layers

Inorg Chem. 2023 Mar 6;62(9):3860-3865. doi: 10.1021/acs.inorgchem.2c04122. Epub 2023 Feb 20.

Authors

Ruixin Guo^{1

2

3}, Shu Guo^{2

3}, Mingjun Xia¹, Lijuan Liu¹, Minjuan Li⁴, Sangen Zhao⁴, Xiaoyang Wang¹

Affiliations

¹ Beijing Center for Crystal Research and Development, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
² Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
³ International Quantum Academy, Shenzhen 518048, China.
⁴ State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.

PMID: 36802565
DOI: 10.1021/acs.inorgchem.2c04122

Abstract

Ba_1.09Pb_0.91Be₂(BO₃)₂F₂ (BPBBF), a previously unreported lead-containing beryllium borate fluoride, has been successfully grown through a high-temperature flux method. Its structure is solved by single-crystal X-ray diffraction (SC-XRD), and it is optically characterized via infrared, Raman, UV-vis-IR transmission, and polarizing spectra as well. SC-XRD data suggests that it can be indexed by a trigonal unit cell (space group P3m1) with lattice parameters a = 4.7478(6) Å, c = 8.3856(12) Å, Z = 1, and V = 163.70(5) Å. This material could be considered as a derivative of the Sr₂Be₂B₂O₇ (SBBO) structural motif. It consists of 2D [Be₃B₃O₆F₃]_∞ layers in the crystallographic ab plane, with divalent Ba²⁺ or Pb²⁺ cations serving as spacers among the adjacent layers. Ba and Pb were found to adopt a disordered arrangement in the trigonal prismatic coordination within the BPBBF structural lattice, which is evidenced by both structural refinements against SC-XRD data and energy dispersive spectroscopy. The UV absorption edge (279.1 nm) and birefringence (Δn = 0.054@ 546.1 nm) of BPBBF are confirmed by UV-vis-IR transmission and polarizing spectra, respectively. The discovery of this previous unreported SBBO-type material, BPBBF, along with other reported analogues such as BaMBe₂(BO₃)₂F₂ (M = Ca, Mg, and Cd), provide a prodigious example for tuning the bandgap, birefringence, and short UV absorption edge via simple chemical substitution.