Suppressing antiparallel dipole alignment: A molecular engineering strategy toward sem-organic UV NLO crystals

Guangsheng Xu; Xue Bai; Zhihua Yang; Xueling Hou; Jian Han; Shilie Pan

doi:10.59717/j.xinn-mater.2026.100218

The Innovation Materials > 2026 Vol. 4 > No. 3 > 100218

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Suppressing antiparallel dipole alignment: A molecular engineering strategy toward sem-organic UV NLO crystals

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

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Corresponding authors: hanjian@ms.xjb.ac.cn (J.H.); slpan@ms.xjb.ac.cn (S.P.)
Received Date: November 28, 2025

Accepted Date: May 12, 2026

Published Online: May 12, 2026

The Innovation Materials 4(3), https://doi.org/10.59717/j.xinn-mater.2026.100218 | Cite this article

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1. A dual molecular strategy to construct non-centrosymmetric semi-organic nonlinear optical crystals.
  
  Identification of a novel highly efficient nonlinear optical chromophore suitable for the ultraviolet region.
  
  (C₃N₃OH₆)(CH₃SO₃), an outstanding nonlinear optical crystal, achieves thermal-induced symmetry breaking.

ABSTRACT

ABSTRACT

Designing crystalline materials with exceptional nonlinear optical (NLO) performance for all-solid-state lasers is a challenging task. In covalent compounds, organic groups with large molecular dipole moments (μ) tend to form antiparallel dimers, leading to a high probability of crystallization in centrosymmetric (CS) structures. This study proposes a dual molecular engineering strategy, which involves reducing the ground-state dipole moment of functional molecules and introducing counterions for dipole competition, to guide self-assembly and optimize the performance of semi-organic crystals. Applied to the CS compound (C₃N₃O₂H₈)(CH₃SO₃)·H₂O (HGM), symmetry breaking occurs through thermally induced structural evolution. The resulting NLO material, (C₃N₃OH₆)(CH₃SO₃) (GLM), exhibits exceptional solar-blind ultraviolet performance. It demonstrates advantages over the commercial semi-organic NLO crystal LAP in several key aspects, including superior thermal stability, a broader transmission range, a stronger second-harmonic response (2.0 × KDP), and a suitable birefringence (Δn = 0.078@546 nm). First-principles calculations reveal that the π-conjugated (C₃N₃OH₆)⁺ cation governs its strong optical anisotropy and NLO response. This work establishes a new paradigm for designing high-performance semi-organic NLO crystals.
- NLO Crystal /
- Dipole Engineering /
- Ultraviolet Region /
- Symmetry Breaking /
- Semi-Organic

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Xu G., Bai X., Yang Z., et al. (2026). Suppressing antiparallel dipole alignment: A molecular engineering strategy toward sem-organic UV NLO crystals. The Innovation Materials 4:100218. https://doi.org/10.59717/j.xinn-mater.2026.100218

Xu G., Bai X., Yang Z., et al. (2026). Suppressing antiparallel dipole alignment: A molecular engineering strategy toward sem-organic UV NLO crystals. The Innovation Materials 4:100218. https://doi.org/10.59717/j.xinn-mater.2026.100218

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Suppressing antiparallel dipole alignment: A molecular engineering strategy toward sem-organic UV NLO crystals

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