A Second-Order Nonlinear Optical Material Consisting of Two π-Conjugated Groups

作者：Li, Minjuan; Wang, Ziyi; Ahmed, Belal^*; Li, Yanqiang; Wang, Han; Song, Yipeng; Song, Xianyu; Kuang, Xiaojun; Luo, Junhua; Zhao, Sangen^*

来源：ChemPlusChem, 2023, 88(3): e202300094.

DOI：10.1002/cplu.202300094

• first-principles calculations
• nonlinear optics
• optoelectronics
• structure-property relationships
• trithiocyanates

This work reports a new second-order nonlinear optical (NLO) material [C(NH2)(3)](3)C3N3S3 (GU(3)TMT), consisting of pi-conjugated planar (C3N3S3)(3-) and triangular [C(NH2)(3)](+) groups. Interestingly, GU(3)TMT exhibits a large NLO response (2.0xKH(2)PO(4)) and moderate birefringence 0.067 at wavelength 550 nm, even though (C3N3S3)(3-) and [C(NH2)(3)](+) do not exhibit the most favorable arrangement in the structure of GU(3)TMT. First-principles calculations suggest that NLO properties mainly originate from the highly pi-conjugated (C3N3S3)(3-) rings, and the pi-conjugated [C(NH2)(3)](+) triangles contribute much less to the overall NLO response. This work will inspire new thoughts with in-depth on the role of pi-conjugated groups in NLO crystals.

• 单位
  中国科学院福建物质结构研究所; 福州大学; 桂林理工大学