Halide Ion-Directed Symmetry Control in π-Conjugated Molecular Crystals
Two halide-containing π-conjugated molecular crystals, (C<sub>5</sub>H<sub>7</sub>BNO<sub>2</sub>)Cl and (C<sub>5</sub>H<sub>7</sub>BNO<sub>2</sub>)Br, were synthesized using pyridine-4-boronic acid and halide ions of differing ionic radii. (C<sub>5</sub>H<sub>7</sub>BNO<sub>2</sub>)Cl adopts a noncentrosymmetric (NCS) structure and exhibits SHG efficiency comparable to KH<sub>2</sub>PO<sub>4</sub>, along with a wide UV transparency window, making it promising for UV NLO applications. In contrast, (C<sub>5</sub>H<sub>7</sub>BNO<sub>2</sub>)Br crystallizes in a centrosymmetric (CS) structure, exhibiting enhanced birefringence. Structural and theoretical analyses reveal that the halide ions influence molecular packing and coplanarity, thereby tuning the symmetry and optical properties. This work demonstrates a halogen-engineering strategy for symmetry control and optical property modulation in π-conjugated molecular crystals, offering a viable pathway for the rational design of high-performance UV NLO materials.
Authors
- Ling Huang (ORCID: https://orcid.org/0000-0002-4007-5766)
- Liling Cao (ORCID: https://orcid.org/0000-0001-9660-2695)
- Shunke Zhang (ORCID: https://orcid.org/0000-0001-8435-011X)
- Xuehua Dong
- Guohong Zou (ORCID: https://orcid.org/0000-0003-4527-0058)
- Han Luo (ORCID: https://orcid.org/0000-0002-9674-0139)
- Yu Zhang (ORCID: https://orcid.org/0000-0002-7551-495X)
Institutions
- Sichuan University (CN)
- Sichuan Normal University (CN)
Publication Details
- Journal
- Inorganic Chemistry
- Published
- 2025-06-17
- DOI
- https://doi.org/10.1021/acs.inorgchem.5c02303
- Citations
- 5
- Primary Topic
- Crystal Structures and Properties
- Type
- article
- Field-Weighted Citation Impact
- 2.14
Funders
- National Natural Science Foundation of China
- Natural Science Foundation of Sichuan Province