(C(NH2)3)2(I2O5F)(IO3)(H2O) and C(NH2)3IO2F2: Two Guanidine Fluorooxoiodates with Wide Band Gap and Large Birefringence

Juhui Cui; Shibin Wang; Abudukadi Tudi; Minqiang Gai; Zhihua Yang; Shilie Pan

doi:10.1021/acs.inorgchem.3c03551

(C(NH₂)₃)₂(I₂O₅F)(IO₃)(H₂O) and C(NH₂)₃IO₂F₂: Two Guanidine Fluorooxoiodates with Wide Band Gap and Large Birefringence

Inorg Chem. 2024 Jan 8;63(1):661-667. doi: 10.1021/acs.inorgchem.3c03551. Epub 2023 Dec 22.

Authors

Juhui Cui^{1

2}, Shibin Wang^{1

2}, Abudukadi Tudi^{1

2}, Minqiang Gai^{1

2}, Zhihua Yang^{1

2}, Shilie Pan^{1

2}

Affiliations

¹ Research Center for Crystal Materials, CAS Key Laboratory of Functional Materials and Devices for Special Environments, Xinjiang Technical Institute of Physics and Chemistry of CAS, Urumqi 830011, China.
² Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.

PMID: 38131323
DOI: 10.1021/acs.inorgchem.3c03551

Abstract

Enhancing anisotropy through an effective synergistic arrangement of anionic and cationic groups is crucial for improving the birefringence optical properties of materials. In this work, by transforming I-O into I-F through the fluorination strategy, two metal-free guanidine fluorooxoiodates (C(NH₂)₃)₂(I₂O₅F)(IO₃)(H₂O) and C(NH₂)₃IO₂F₂ and one guanidine iodate C(NH₂)₃IO₃ were successfully synthesized using the hydrothermal method. An unprecedented dimer [I₂O₅F] formed by [IO₃F] and [IO₃] in (C(NH₂)₃)₂(I₂O₅F)(IO₃)(H₂O) was found, which greatly enriches the structural diversity of fluorooxoiodates. All three compounds feature a relatively large birefringence (Δn = 0.068, 0.110 and 0.075 at 546 nm) and a short ultraviolet cutoff edge. The theoretical calculation was carried out to understand the electronic structures and linear optical properties.