Luminescent pillared LnIII–ZnII heterometallic coordination frameworks with two kinds of N-heterocyclic carboxylate ligands

•Four new LnIII–ZnII heterometallic coordination frameworks with two types of topologies have been synthesized.•Metal oxides and two kinds of N-heterocyclic carboxylate ligands were used for the construction of targeted coordination polymers.•The luminescent properties of the coordination polymers are investigated.

In our efforts toward rational design and systematic synthesis of ‘pillar-layer’ structure coordination frameworks, four new LnIII–ZnII heterometallic coordination polymers (CPs) based on two kinds of N-heterocyclic carboxylic ligands with formula {[LnZn(L1)2(L2)(H2O)m]·nH2O}∞ (Ln=La (1), Eu (2), Gd (3) and Dy (4), m=3 (for 1) and 2 (for 2–4), n=8 (for 1) and 7 (for 2–4), H2L1=pyridine-2,3-dicarboxylate acid, HL2=isonicotinic acid), have been synthesized under hydrothermal reaction of Ln2O3, ZnO, H2L1 and HL2. CP 1 has a three-dimensional (3D) structure with a (3,6)-connected sit topology network, while CPs 2–4 are isostructural with 3D single-node pcu alpha-Po topology network. Also, luminescent properties of these CPs have also been investigated. The emission of 1 and 3 should be attributed to the coordination-perturbed ligand-centered luminescence and the emission spectra of 2 and 4 show the characteristic bands of the corresponding LnIII ions.

Graphical abstractFour new 3D LnIII–ZnII coordination frameworks with “pillar-layer” sit or pcu alpha-Po topology have been successfully obtained. Moreover, the photoluminescent properties of compounds 1–4 have also been investigated.Figure optionsDownload full-size imageDownload as PowerPoint slide