Ag(I)-Coordinated Supramolecular Metallogels Based on Schiff Base Ligands: Structural Characterization and Reversible Thixotropic Property

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• 作者：Min Xue ; Yanchao L眉 ; Qingqing Sun ; Kaiqiang Liu ; Zhen Liu ; Ping Sun
• 刊名：Crystal Growth & Design
• 出版年：2015
• 出版时间：November 4, 2015
• 年：2015
• 卷：15
• 期：11
• 页码：5360-5367
• 全文大小：532K
• ISSN：1528-7505

文摘

Three Schiff base ligands containing two pyridine rings, S1, S2, and S3, show strong gelation abilities with AgNO<sub>3sub> in several pure or mixed solvents at room temperature. <sup>1sup>H NMR and Fourier transform infrared spectroscopy measurements not only demonstrated the coordination interaction between silver ion and nitrogen atom of the pyridine ring of the S2 ligand in S2-Ag metallogel, but also showed that hydrogen bonding contributes to the formation of the metallogels. In particular, S2-Ag metallogel shows a super smart and fully reversible thixotropic property, which has been rarely reported before in metallogels. X-ray diffraction (XRD) analysis revealed that S2-Ag metallogel in DMF takes a mixture of hexagonal and tetragonal packing modes. On the basis of the results of XRD and mass spectrometry analysis, a possible structure evolution process for the gel was proposed. And this model was further demonstrated by the results of polarizing microscopy and thermogravimetric analysis of S2-Ag metallogel.