Parallel Alignment of π-Conjugated Anions in Hydroisocyanurates Enhancing Optical Anisotropy
2019; American Chemical Society; Volume: 58; Issue: 14 Linguagem: Inglês
10.1021/acs.inorgchem.9b01646
ISSN1520-510X
AutoresXianghe Meng, Fei Liang, Jian Tang, Kaijin Kang, Tixian Zeng, Wenlong Yin, Ruixin Guo, Zheshuai Lin, Mingjun Xia,
Tópico(s)Crystallography and molecular interactions
ResumoBirefringent crystals with optical anisotropy, which are employed to modulate the polarization of light, play a vital role in many fields of the optical industry. In this Communication, two mixed alkali metal hydroisocyanurates, RbLi(H2C3N3O3)2·2H2O (I) and CsLi(H2C3N3O3)2·2H2O (II), were synthesized by a simple aqueous solution method, and they feature layered structures composed of ∞2[H2C3N3O3]− ribbons through hydrogen bonds with the separation of water molecules and alkali cations. They exhibit a simultaneously short ultraviolet cutoff and giant birefringence, resulting from the perfect parallel alignment of π-conjugated (H2C3N3O3)− anions. Interestingly, the first-principles calculations elucidated that the electronic states and optical properties are slightly different owing to the distinct p−π interaction between alkaline metals and the (H2C3N3O3)− group despite the isostructural crystallographic lattice.
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