由柔性配体庚二酸组装的微孔稀土配位高聚物

合成了3种新的庚二酸(H2pim)稀土配位高聚物Nd(Hpim)(pim)(H2O)]n·2nH2O(1),RE2(pim)3(H2O)]n·nH2ORE=Er(2),RE=Ho(3)],并通过元素分析红外光谱和单晶X射线衍射技术确定了其组成和晶体结构.配合物1为具有微孔的三维网状结构.配合物2和3同构,通过两种类型的O—H…O氢键将由配位键构筑的二维骨架结构组装成三维超分子结构.在这3个配合物中,庚二酸配体在同一配合物的结构中均存在不同的构象,体现了柔性配体不同于刚性配体的配位特点.

Microporous Rare Earth Coordination Polymers Constructed by a Flexible Pimelic Acid Ligand

Three new rare earth coordination polymers of pimelic acid (H2pim), Nd(Hpim)(pim)(H2O)] ·2H2O(1) and RE 2(pim)3(H2O)] ·H2O RE=Er(2), RE=Ho(3)] , were synthesized and characterized by elemental analyses, IR spectra and X-ray crystallography. In complex 1, Nd(Ⅲ) is bridged by pimelic acid ligands to form3D microporous structure. There are two types of lattice water in complex 1. One lies in microporous structure and the other is used to form O—H…O hydrogen bond. In complex 2, Er(Ⅲ) ions are connected by pimelate ligands into a 2D microporous layer structure. Two types of O—H…O hydrogen bonds make 2D framework into 3D supramolecular structure. Single crystal X-ray diffraction analyses shows that complex 3 is isostructural to complex 2. In three complexes, different conformations for H2pim are found, showing that coordinating characteristics of the flexible ligands are different from the rigid ligands.