CsHfF4(IO3): A Hafnium Iodate Exhibiting a Strong Second-Harmonic-Generation Effect and a Wide Band Gap Achieved by Mixed-Ligand Acentric Coordination

Yu Huang; Bing-Xuan Li; Chun-Li Hu; Bing-Ping Yang; Jiang-Gao Mao

doi:10.1021/acs.inorgchem.3c00189

CsHfF₄(IO₃): A Hafnium Iodate Exhibiting a Strong Second-Harmonic-Generation Effect and a Wide Band Gap Achieved by Mixed-Ligand Acentric Coordination

Inorg Chem. 2023 Feb 27;62(8):3343-3348. doi: 10.1021/acs.inorgchem.3c00189. Epub 2023 Feb 15.

Authors

Yu Huang^{1

2}, Bing-Xuan Li¹, Chun-Li Hu¹, Bing-Ping Yang^{1

3}, Jiang-Gao Mao^{1

3}

Affiliations

¹ State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, P. R. China.
² State Key Laboratory of Material Processing and Die and Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China.
³ University of Chinese Academy of Sciences, Beijing 100049, P. R. China.

PMID: 36790215
DOI: 10.1021/acs.inorgchem.3c00189

Abstract

A new polar hafnium iodate, CsHfF₄(IO₃), was successfully designed and synthesized by integrating fluorinated hafnium-oxygen polyhedra (HfF₆O₂) and IO₃^- anionic functional groups. Owing to the weak electronic effect of Hf⁴⁺ and the bond-network-induced out-of-center distortion of the HfF₆O₂ dodecahedra, CsHfF₄(IO₃) achieves a good balance between a strong second-harmonic-generation effect (3.5 × KH₂PO₄) and a rather large band gap (4.47 eV), which is the largest among the d⁰ transition-metal iodates. In addition, CsHfF₄(IO₃) possesses a wide transparent region (0.27-9.9 μm), a large birefringence for phase-matching (0.161), and a high laser-induced damage threshold (55.41 MW cm^-2, 26 × AgGaS₂) and is nonhygroscopic. This work indicates that the integration of mixed-ligand acentric coordination polyhedra and functional groups containing lone electron pairs is an effective strategy for developing novel inorganic nonlinear-optical materials with balanced overall properties.