Syntheses, Structures, and Photoluminescence Properties of a Series of 3D Zn‐Ln Heterometallic Complexes with 2,3‐Pyrazine Dicarboxylic Acid as a Bridging Ligand

Abstract

A series of 3D d–f heterometallic coordination polymers, {[Ln2Zn(Pzdc)4(H2O)6]·2H2O}n [Ln = La (1), Pr (2), Nd (3), Sm (4), Eu (5), Gd (6), Tb (7), Dy (8)] (H2Pzdc = 2,3‐pyrazine dicarboxylic acid), were synthesized by one‐pot reactions under hydrothermal conditions. X‐ray crystallographical analysis and powder X‐ray diffraction analysis reveal that the complexes 1–8 are isostructural and adopt a multi‐parallel quadrilateral channel network structure with {4.6·2}2{4·2.6·2.8·2}{6·3}2{6·5.8}2 topology, in which the central LnIII ion is nine‐coordinate by four oxygen atoms and two nitrogen atoms from four ligands and three oxygen atoms from three coordinated H2O molecules and the central ZnII ion is six‐coordinate by four oxygen atoms and two nitrogen atoms from four ligands. Moreover, the photophysical properties related to the electronic transition for complexes 4, 5, 7, and 8 were investigated by the excitation and emission spectra as well as the emission lifetimes.