A luminescent Eu coordination polymer with near-visible excitation for sensing and its homologues constructed from 1,4-benzenedicarboxylate and 1H-imidazo[4,5-f][1,10]-phenanthroline
A luminescent Eu coordination polymer with near-visible excitation for sensing and its homologues constructed from 1,4-benzenedicarboxylate and 1H-imidazo[4,5-f][1,10]-phenanthroline
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DOI：
10.1039/d0ce01256d
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发表时间：
2020-12-07
期刊：
影响因子：
3.1
通讯作者：
Li, Xia
中科院分区：
文献类型：
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作者：
Liu, Dongmei;Dong, Gaoyun;Li, Xia
以1，4-苯二甲酸（BDC）和1H-咪唑并[4，5-f][1，10]-邻菲咯啉（IP）为原料，合成了一种铕配位聚合物及其同系物，即五种镧系配位聚合物[Ln（BDC）（1.5）（IP）（H2O）]中心点nH（2）O（Ln = Sm 1，Eu 2，Gd 3，Tb 4，Dy 5）.它们具有二维网络结构，LnO（6）N（2）单元通过桥联BDC配体形成，而IP分子作为末端配体以双齿螯合模式与Ln（iii）离子配位。记录了这些化合物的发光。Eu-CP具有几个明显的优点，包括最大激发波长高达375 nm的宽激发带（315 nm <λ（ex）< 410 nm）、可见红光发射以及在4-10的宽pH范围内良好的水稳定性。以Eu-CP为化学传感器，在375 nm激发波长下实现了大黄素在水溶液中的高效发光传感。值得注意的是，当用400 nm可见光激发时，Eu-CP也表现出类似的发光传感能力。通过UV-vis吸收光谱研究和密度泛函理论（DFT）计算，探讨了大黄素对Eu-CP荧光猝灭的可能机制。同样，在375或400 nm的近可见光下，也实现了常见离子（Fe 3+，Ag+，Cr2 O 72-/CrO 42-，MnO 4-）的检测。实验结果表明，Eu-CP是一种优良的发光化合物，其激发波长可调至近可见光范围（350 nm < lambda（ex）< 410 nm），可实现强发光和发光传感。
A Eu-coordination polymer and its homologues, namely, five lanthanide coordination polymers (Ln-CPs), [Ln(BDC)(1.5)(IP)(H2O)]center dot nH(2)O (Ln = Sm 1, Eu 2, Gd 3, Tb 4, Dy 5), were constructed from 1,4-benzenedicarboxylate (BDC) and 1H-imidazo[4,5-f][1,10]-phenanthroline (IP). They feature 2D network structures with LnO(6)N(2) units by bridging BDC ligands, while the IP molecules as terminal ligands are coordinated to the Ln(iii) ions in bidentate chelating mode. The luminescence of these compounds was recorded. Eu-CP has several distinct advantages including a broad excitation band (315 nm < lambda(ex) < 410 nm) with a maximum excitation wavelength of up to 375 nm, visible red emission, and a good aqueous stability in a wide pH range of 4-10. Using Eu-CP as a chemical sensor, high luminescence sensing for emodin in aqueous medium was realized at excitation of 375 nm. Remarkably, when excited with 400 nm visible light, Eu-CP also exhibited a similar luminescence sensing capacity. UV-vis absorption spectral studies and density functional theory (DFT) calculations were performed to elucidate the possible mechanism of luminescence quenching of Eu-CP by emodin. Similarly, the detection of common ions (Fe3+, Ag+, Cr2O72-/CrO42-, MnO4-) was also realized under near-visible light of 375 or 400 nm. The experimental results prove that Eu-CP is an excellent luminescent compound, as its excitation wavelength can be adjusted to the near-visible range (350 nm < lambda(ex) < 410 nm), and strong luminescence and luminescence sensing for analytes can be achieved.