State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fujian, Fuzhou, 350002, PR China.
Inorg Chem. 2011 Jun 6;50(11):5242-8. doi: 10.1021/ic200579j. Epub 2011 May 9.
A conjugated ligand, 2-(carboxylic acid)-6-(2-benzimidazolyl) pyridine (Hcbmp), and a series of Lanthanide metal-organic frameworks (MOFs) Ln(2)(cbmp)(ox)(3)(H(2)O)(2)·2H(3)O(+)·7H(2)O (Ln = Sm (3), Eu (4), and Gd (5), H(2)ox = oxalic acid) have been designed and assembled. To elucidate how the conjugated ligands modulate the structures and luminescence properties, we carried out the structural characterizations and luminescence studies of complexes 3 and 4, and their corresponding oxalate complexes [Ln(ox)(1.5)(H(2)O)(3)]·2H(2)O (Ln = Sm (1) and Eu (2)) were also investigated for comparison. The changes of luminescence behaviors upon dehydration and D(2)O-rehydration processes are presented and discussed in detail. The results indicated that, the cbmp(-) ligands distribute on both sides of the ox(-)-Ln bilayer network to construct a sandwich structure. Moreover, the lowest triplet state of cbmp(-) ligands can match well the energy levels of the Sm(3+) and Eu(3+) cations which allow the preparation of new Ln-MOF materials with enhanced luminescence properties. Meanwhile, the crystallinity of solid states produces more substantial change in the luminescence behaviors than removal or replacement of effective nonradiative relaxers.
一种共轭配体 2-(羧酸)-6-(2-苯并咪唑基)吡啶（Hcbmp）和一系列镧系金属有机骨架（MOFs）Ln(2)(cbmp)(ox)(3)(H(2)O)(2)·2H(3)O(+)·7H(2)O（Ln = Sm(3)、Eu(4)和 Gd(5)，H(2)ox = 草酸）被设计并组装。为了阐明共轭配体如何调节结构和发光性质，我们对配合物 3 和 4 进行了结构表征和发光研究，并对其相应的草酸盐配合物[Ln(ox)(1.5)(H(2)O)(3)]·2H(2)O（Ln = Sm(1)和 Eu(2)）进行了研究比较。详细介绍和讨论了脱水和 D(2)O 复水过程中发光行为的变化。结果表明，cbmp(-)配体分布在 ox(-)-Ln 双层网络的两侧，以构建夹层结构。此外，cbmp(-)配体的最低三重态可以很好地与 Sm(3+)和 Eu(3+)阳离子的能级匹配，从而允许制备具有增强发光性能的新型 Ln-MOF 材料。同时，固态的结晶度对发光行为的影响比有效非辐射弛豫剂的去除或取代更大。
