Syntheses, crystal structures and properties of four novel zinc(II) complexes assembled from versatile 1,2,3,5-benzenetetracarboxylic acid and bridging dipyridyl ligands

详细信息    查看全文

• 作者：Chang-Kun Xia ; ^{ckxia@163.com" class="auth_mail" title="E-mail the corresponding author} ; Fan Wu ; Kai Yang ; Yun-Long Wu ; Xiao-Jing Lu
• 关键词：Transition metal complexes ; 1 ; 2 ; 3 ; 5-Benzenetetracarboxylic acid ; Pyridine ; Photoluminescence ; Polymer
• 刊名：Polyhedron
• 出版年：2016
• 出版时间：7 July 2016
• 年：2016
• 卷：112
• 期：Complete
• 页码：78-85
• 全文大小：2175 K

文摘

Four novel metal–organic coordination polymers constructed from 1,2,3,5-benzenetetracarboxylic acid and bridging dipyridyl ligands, namely, [Zn(H₂btec)(bpy)_0.5] (1), [Zn(H₂btec)(bpyE)_0.5] (2), [Zn₂(btec)(bpye)H₂O]·2H₂O (3), and [Zn(Hbtec)(Hbpyp)]·H₂O (4) (H₄btec = 1,2,3,5-benzenetetracarboxylic acid, bpy = 4,4′-bipyridine, bpyE = 1,2-bis(4-pyridyl)ethylene, bpye = 1,2-bis(4-pyridyl)ethane, bpyp = 1,3-bis(4-pyridyl)propane) have been synthesized with hydrothermal methods and characterized by elemental analysis, IR, TGA, and single crystal X-ray diffraction. All the zinc(II) atoms are four coordinated in the four complexes, the different nitrogen coligands were found to remarkably affect the framework topologies. The zinc(II) atoms are bridged by H₂btec²⁻ with adjacent carboxylate groups into a one-dimensional double chain in complexes 1 and 2, the chains are further connected into a two dimensional sheet by the rigid dipyridyl ligands in the two complexes. However, the H₄btec ligands are deprotoned into btec⁴⁻ ligand and act as five-dentated ligands, which connect the zinc(II) atoms into a two-dimensional double layer with the help of flexible bpye ligands in complex 3. Interestingly, the H₄btec ligands are deprotoned into Hbtec³⁻ ligand rather than H₂btec²⁻ and btec⁴⁻ in complex 4, and the three adjacent carboxylate groups connected the zinc(II) atoms into another kind of one dimensional double chain. Different from complexes 1, 2, and 3, the bpyp is protonated and acts as a terminal ligand rather than bridging one, the protonated N–H groups form hydrogen bonding interactions with the adjacent chain and thus bridging the chains into a two-dimensional sheet. Besides the coordination mode of the H₄btec ligands, the final structures are also influenced greatly by the hydrogen bonding interactions of the H₄btec ligands, one-dimensional channel constructed via hydrogen bonding interactions of H₄btec ligands in complexes 1, 2, and 4 with dipyridyl ligands as guest molecules. Thermal stabilities and photoluminescent properties of complexes 1–4 were also examined.