Reversible water intercalation accompanied by coordination and color changes in a layered metal-organic framework.
Reversible water intercalation accompanied by coordination and color changes in a layered metal-organic framework.
复制标题
DOI：
10.1021/ic9003356
复制
发表时间：
2009-06
影响因子：
4.6
通讯作者：
Partha Mahata;K. Ramya;S. Natarajan
中科院分区：
文献类型：
--
作者：
Partha Mahata;K. Ramya;S. Natarajan
一种新型二维3d-4f混合金属混合二羧酸盐（同环和杂环），其化学式为 [Gd(2)(H(2)O)(2)Ni(H(2)O)(2)(1,2-bdc)(2)(2,5-pydc)(2)].8H(2)O (1; 1,2-H(2)bdc = 采用水热法制备了1,2-苯二甲酸和2,5-H(2)pydc = 2,5-吡啶二甲酸)。该结构具有由共享边缘的 GdO(9) 多面体单元形成的无限一维 -Gd-O-Gd- 链，完全由 Gd(3+) 离子和 1,2-bdc 单元之间的连接产生。这些链通过[Ni(H(2)O)(2)(2,5-pydc)(2)](2-)金属配体连接，形成二维层状排列。层的堆叠在层间区域产生亲水和疏水空间。由骨架外水分子形成的一维水梯结构占据亲水区域，而1,2-bdc的苯环占据疏水区域。据我们所知，本发明的化合物代表了3d-4f混合金属羧酸盐的第一个例子，其中两种不同的芳香族二羧酸根阴离子充当连接体。使用密度泛函理论计算评估了水团簇的稳定能。 1 中的水分子是完全可逆的，伴随着颜色的变化（绿蓝色到棕色）和 Ni(2+) 离子周围的配位（八面体到扭曲的四面体）。
A new two-dimensional 3d-4f mixed-metal mixed dicarboxylate (homocyclic and heterocyclic) of the formula [Gd(2)(H(2)O)(2)Ni(H(2)O)(2)(1,2-bdc)(2)(2,5-pydc)(2)].8H(2)O (1; 1,2-H(2)bdc = 1,2-benzenedicarboxylic acid and 2,5-H(2)pydc = 2,5-pyridinedicarboxylic acid) has been prepared by employing the hydrothermal method. The structure has infinite one-dimensional -Gd-O-Gd- chains formed by the edge-shared GdO(9) polyhedral units, resulting exclusively from the connectivity between the Gd(3+) ions and the 1,2-bdc units. The chains are connected by the [Ni(H(2)O)(2)(2,5-pydc)(2)](2-) metalloligand, forming the two-dimensional layer arrangements. The stacking of the layers creates hydrophilic and hydrophobic spaces in the interlamellar region. A one-dimensional water ladder structure, formed by the extraframework water molecules, occupies the hydrophilic region while the benzene ring of 1,2-bdc occupies the hydrophobic region. To the best of our knowledge, the present compound represents the first example of a 3d-4f mixed-metal carboxylate in which two different aromatic dicarboxylate anions act as the linkers. The stabilization energies of the water clusters have been evaluated using density functional theory calculations. The water molecules in 1 are fully reversible accompanied by a change in color (greenish blue to brown) and coordination around Ni(2+) ions (octahedral to distorted tetrahedral).