Lanthanide-organic frameworks based on terphenyl-tetracarboxylate ligands: syntheses, structures, optical properties and selective sensing of nitro explosives

• 来源期刊: 中国科学:化学（英文版）
• 年，卷（期）: 2017,（8）
• 页码范围: 1130-1135
• 页数: 6页
• 语种: 英文
• DOI: 10.1007/s11426-016-9006-x

摘要

Three isostructural three-dimensional (3D) lanthanide-based metal-organic frameworks [Ln2L(H2L)(NMP)2]·H2O (Ln-Sm(1),Eu (2),Gd (3);H4L-1,1′∶4′,1″-terphenyl-2′,4,4″,5′-tetracarboxylic acid;NMP-N-methyl-2-pyrrolidone) have been synthesized and structurally characterized.In 1-3,two Ln3+ ions are doubly-bridged by two oxygen atoms of two carboxylate groups to form the dinuclear Ln2(Ocoo)2 unit.Each Ln2(Ocoo)2 unit links with four H2L2 ligands and four L4-ligands to lead to the 3D framework,which can be rationalized as a new trinodal 4,4,8-connected (44.62)(45.6)(412.616) topological network by considering the dinuclear Ln2(Ocoo)2 units as 8-connected nodes and L4-/H2L2-ligands as planar 4-connected nodes,respectively.1 and 3 exhibit blue emission originated from the ligand with the emission maximum at 384 nm,while 2 shows intense characteristic red emission of Eu3+ ions and weak ligand-centered emission.Moreover,2 has fluorescent quenching response towards the aromatic nitro compounds,especially for the 3,4-dinitrotoluene (3,4-DNT) with the linear Stern-Volmer relationship in the concentration range of 0-1 mM and the quenching constant (Ksv) of 2.084× 103 M-1.