Designing a Deep-UV Nonlinear Optical Fluorooxosilicophosphate

Qingran Ding; Xiaomeng Liu; Sangen Zhao; Yusong Wang; Yanqiang Li; Lina Li; Shuai Liu; Zheshuai Lin; Maochun Hong; Junhua Luo

doi:10.1021/jacs.0c00060

Designing a Deep-UV Nonlinear Optical Fluorooxosilicophosphate

J Am Chem Soc. 2020 Apr 8;142(14):6472-6476. doi: 10.1021/jacs.0c00060. Epub 2020 Mar 24.

Authors

Qingran Ding^{1

2}, Xiaomeng Liu^{3

2}, Sangen Zhao^{1

2}, Yusong Wang⁴, Yanqiang Li¹, Lina Li¹, Shuai Liu¹, Zheshuai Lin³, Maochun Hong¹, Junhua Luo^{1

2}

Affiliations

¹ State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, 155 Yangqiao Road West, Fuzhou, Fujian 350002, P. R. China.
² University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
³ Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
⁴ University of Science and Technology of China, Hefei, Anhui 230026, P. R. China.

PMID: 32202111
DOI: 10.1021/jacs.0c00060

Abstract

Structures composed of SiO_xF_6-x (x = 1, 2, 3, 4, 5) or SiO_xF_4-x (x = 1, 2, 3) species have thus far been observed in only a few compounds, and their functional properties are completely unknown in silicate chemistry. By introducing the least electronegative element, cesium, and the most electronegative element, fluorine, into the silicophosphate system, we successfully designed the first noncentrosymmetric fluorooxosilicophosphate with Si-F bonds, CsSiP₂O₇F, whose structure consists of an unprecedented SiP₂O₁₀F moiety containing hexacoordinate SiO₅F species. The experimental results highlight CsSiP₂O₇F as the first fluorooxosilicophosphate deep-UV nonlinear optical (NLO) material. The first-principles calculations reveal that the SiP₂O₁₀F moiety is a new type of NLO-active unit and that both cesium and fluorine increase the deep-UV transparency of CsSiP₂O₇F. This work provides a new source of deep-UV NLO materials and insights into obtaining noncentrosymmetric structures that are indispensable to functional materials in nonlinear optics, piezoelectricity, ferroelectric, pyroelectricity, etc.