Variable dimensionality of the anion framework in four new borophosphates and fluoroborophosphates with short cutoff edges

• Published in: Dalton transactions : an international journal of inorganic chemistry 2022-02, Vol.51 (7), p.284-2845
• Main Authors: Zhang, Ruonan, Guo, Siru, Wang, Xuping, Yang, Rong, Chen, Zhen, Zhang, Wenyao, Zhang, Fangfang, Guo, Zhiyong, Han, Shujuan, Yang, Zhihua
• Format: Article
• Language: English
• Subjects: Anions; Crystals; High temperature; Infrared spectroscopy; Lithium; Optical properties; Single crystals; Spectrum analysis
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/d1dt04266a

Two new borophosphates, Cs 3 B 3 P 4 O 16 and Li(NH 4 ) 2 B 3 P 4 O 16 , and two new fluoroborophosphates, K 4 B 2 P 2 O 9 F 2 and Rb 3 B 2 PO 5 F 4 , have been obtained via the high-temperature solution method. Single-crystal X-ray diffraction indicates that all of them exhibit various anion frameworks although they crystallize in the same space group, P 2 1 / c . Two-dimensional (2D) [B 3 P 4 O 16 ] ∞ layers and a 3D [B 3 P 4 O 16 ] ∞ network can be found in Cs 3 B 3 P 4 O 16 and Li(NH 4 ) 2 B 3 P 4 O 16 , respectively, while isolated [B 2 P 2 O 9 F 2 ] and [B 2 PO 5 F 4 ] exist in K 4 B 2 P 2 O 9 F 2 and Rb 3 B 2 PO 5 F 4 , respectively. The effect of the alkali metal cation size on the framework structures of Cs 3 B 3 P 4 O 16 and Li(NH 4 ) 2 B 3 P 4 O 16 has been discussed in detail. The IR spectra confirm their structural validity. UV-Vis-NIR diffuse reflectance spectroscopy indicates that the new compounds exhibit short cutoff edges. In addition, theoretical calculations were carried out to understand their electronic structures and optical properties. Four new borophosphates and fluoroborophosphates constructed by using tetrahedral groups, which possess variable dimensionality of the anion framework, have been obtained.