Na2BaB12O18F4: A Mixed Alkali/Alkaline-Earth Metal Fluorooxoborate with Two Unprecedented Interpenetrating Three-Dimensional B–O/F Anionic Networks and a Short Ultraviolet Cutoff Edge

• Published in: Inorganic chemistry 2023-03, Vol.62 (12), p.5008-5015
• Main Authors: Baiheti, Tuohetijiang, Tudi, Abudukadi, Gai, Minqiang, Wang, Xuping, Han, Shujuan
• Format: Article
• Language: English
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.3c00203

Fluorooxoborates are promising yet largely untapped crystal materials for linear and nonlinear optical applications. The introduction of a strong electronegative F atom into an oxyboron anionic group offers a virtually unlimited chance for structural engineering and ultimately purposeful tuning of the macroscopic optical properties of the crystal. Herein, a new mixed alkali/alkaline-earth fluorooxoborate, Na2BaB12O18F4, was synthesized in a closed system. Na2BaB12O18F4 features a [B6O11F2] fundamental building unit (FBB), which polymerizes into two new (first example) independent interpenetrating three-dimensional (3D) B–O/F anionic networks constructed entirely from BO3 and BO3F units. Based on optical characterizations and the first-principles calculations, Na2BaB12O18F4 exhibits a moderate birefringence (0.054 @ 1064 nm) and a short ultraviolet (UV) cutoff edge (below 190 nm). The successful synthesis and characterization of Na2BaB12O18F4 may speed up the subsequent discovery of other mixed alkali/alkaline-earth metal fluorooxoborates.