Noncentrosymmetric γ - Cs2I4O11 Obtained from IO4 Polyhedral Rearrangements in the Centrosymmetric β - Phase

Ming-Li Liang; Matthew Lacroix; Ce Tao; Michael J Waters; James M Rondinelli; P Shiv Halasyamani

doi:10.1021/acs.inorgchem.2c04450

Noncentrosymmetric γ - Cs₂I₄O₁₁ Obtained from IO₄ Polyhedral Rearrangements in the Centrosymmetric β - Phase

Inorg Chem. 2023 Feb 13;62(6):2942-2950. doi: 10.1021/acs.inorgchem.2c04450. Epub 2023 Jan 30.

Authors

Ming-Li Liang¹, Matthew Lacroix¹, Ce Tao¹, Michael J Waters², James M Rondinelli², P Shiv Halasyamani¹

Affiliations

¹ Department of Chemistry, University of Houston, Houston, Texas 77204, United States.
² Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States.

PMID: 36716235
DOI: 10.1021/acs.inorgchem.2c04450

Abstract

We report the synthesis and optical properties of noncentrosymmetric (NCS) γ-Cs₂I₄O₁₁ that was obtained through IO₄ polyhedral rearrangements from centrosymmetric (CS) β-Cs₂I₄O₁₁. Trifluoroacetic acid (TFA) acts as a structure-directing agent and plays a key role in the synthesis. It is suggested that the function of TFA is to promote rearrangement reactions found in the organic synthesis of stereoisomers. γ-Cs₂I₄O₁₁ crystallizes in the NCS monoclinic space group P2₁ (No. 4) and exhibits a strong second-harmonic-generation (SHG) response of 5.0 × KDP (KH₂PO₄) under 1064 nm laser radiation. Additional SHG experiments indicate that the material is type I phase matchable. First-principles calculations show that SHG intensity mainly comes from its d₃₄, d₂₁, and d₂₃ SHG tensor components. The synthetic strategy of discovering γ-Cs₂I₄O₁₁ provides a new way for designing novel NCS SHG materials.