Combination of N‑Arylstilbazolium Organic Nonlinear Optical Chromophores with Iodoargentates: Structural Diversities and Optical Properties

• Published in: Crystal growth & design Vol. 18; no. 7; pp. 3827 - 3840
• Main Authors: Wang, Yu-Kang, Zhao, Li-Ming, Fu, Yu-Qing, Chen, Zhao, Lin, Xiao-Yan, Wang, Dao-Hua, Li, Yi, Li, Hao-Hong, Chen, Zhi-Rong
• Format: Journal Article
• Language: English
• Published: American Chemical Society 05.07.2018
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/acs.cgd.8b00033

A combination of N-arylstilbazolium organic nonlinear optical chromophores with iodoargentates results in five new hybrids, i.e., [(DAST)­(Ag2I3)] n (1), [(DMAQS)­(Ag2I3)] n (2), [(DPAS)­(Ag2I3)] n (3), [(DPTAS)2­(Ag5I7)] n (4), and [(CEMAS)2­(Ag5I7)] n (5). Among them, the former four are centrosymmetric, and 5 is non-centrosymmetrical (space group Pna21) with the introduction of a cyano group in an organic chromophore. The (Ag5I7) n 2n– chains in 4 and 5 are special, in which that of 4 is constructed from Ag5I10 building blocks with a μ6-I σ-bonding to six Ag ions, and that in 5 is the connection of a cubane-like Ag4I4 core with bridged AgI4 tetrahedra. UV/vis/near-IR adsorptions and near-IR photoluminescences have been observed. All the organic chromophores are stacked as head-to-tail arrangements, resulting in second harmonic generation (SHG) inactive in 1–4. But 5 is SHG active without J-aggregation of organic chromophore, whose symmetry break was driven by the formation of hydrogen bonds around the cyano group. The SHG activity of 5 originates from the polarizations of the asymmetric contribution of Ag5I9 4– unit mixing with non-centrosymmetrical (CEMAS)2 2+ pair. Theoretical calculations were carried out to disclose their electronic structures.