Novel Structures and Luminescence Properties of Lanthanide Coordination Polymers with a Novel Flexible Polycarboxylate Ligand

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• 作者：Qilong Zhu ; Tianlu Sheng ; Ruibiao Fu ; Shengmin Hu ; Jianshan Chen ; Shengchang Xiang ; Chaojun Shen ; Xintao Wu
• 刊名：Crystal Growth & Design
• 出版年：2009
• 出版时间：December 2, 2009
• 年：2009
• 卷：9
• 期：12
• 页码：5128-5134
• 全文大小：1064K
• 年卷期：v.9,no.12(December 2, 2009)
• ISSN：1528-7505

文摘

A series of lanthanide coordination polymers with a novel flexible hexapodal ligand, formulated as [Ln₂(TTHA)(H₂O)₄]·9H₂O (TTHA = 1,3,5-triazine-2,4,6-triamine hexaacetic acid; Ln = 1, Eu; 2, Tb; 3, Gd; 4, Dy) and [Yb₂(TTHA)(H₂O)₂] (5) have been hydrothermally synthesized and characterized. Complexes 1−4 possess the same three-dimensional 4-connected 4²8⁴ networks constructed from Ln₂(CO₂)₄ units with two different shapes of three-dimensional channels determining certain adsorption for H₂ and CH₄. The thermogravimetric analyses and XRD data show that the guest water molecules and a coordinated water molecule with each metal center are thermally unstable, but the orders of the framework structures of complexes 1−4 are thermally stable to 400 °C. Complex 5 shows a 2D network with 1D inorganic chains bridged by the ligands, and the 3D network was extended through π···π stacking interactions between triazine rings. Photoluminescence measurements show that complexes 1 and 2 are highly emissive at room temperature with quantum yields of 31% and 89%, which even amount to unexpectedly 77% and 96% after thermal treatments at 394 and 343 nm, respectively, and may be good candidates for light-emitting diodes (LEDs) and light applications.