Synthesis, structures, luminescent and magnetic properties of four coordination polymers with the flexible 1,3-phenylenediacetate ligands

Four coordination polymers, [Zn(pda)(bpy)(H2O)]n·nH2O (1), [Cd(pda)(prz)(H2O)]n (2), [Co3(μ3-OH)2(pda)2(pyz)]n·2nH2O (3) and [Pr2(pda)3(H2O)2]n (4) (H2pda=1,3-phenylendiacetic acid, bpy=4,4′-bipyridine, prz=piperazine and pyz=pyrazine) have been hydrothermally synthesized and characterized. Complex 1 is a 1D wheel-like chain structure, which is further extended into a 3D metal-organic supramolecular framework by H-bonds and π–π stacking interactions. Complex 2 is a 1D ladder-like chain structure, which is also further extended into a 3D metal-organic supramolecular framework by H-bonds. Complex 3 possess a 2D sheet structure with infrequent two pairs of double-helix chains. Complex 4 features a 3D structure. Both 1 and 2 display strong blue fluorescent emission at room temperature. Magnetic susceptibility measurements of complexes 3 and 4 exhibit antiferromagnetic interactions between the nearest metal ions, with C=9.99 and 3.43 cm3 mol−1 K, and θ=−23.9 and −46.3 K, respectively.

Graphical abstractFour new coordination polymers with 1,3-phenylenediacetate ligands have been hydrothermally synthesized and characterized.Complexes 1 and 2 display strong blue fluorescent emission at room temperature. Magnetic susceptibility measurements of 3 and 4 exhibit antiferromagnetic interactions between the nearest metal centers.Figure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights► Coordinative property of H2pda ligand was shown when bonded by different block metals. ► Careful selection of co-ligand and metals resulted in dramatic framework evolution. ► (c) The compounds constructed with Zn2+ and Cd2+ exhibit strong blue fluorescent emission. ► The magneto-structural correlation of the complexes constructed with Co2+ and Pr3+ was elucidated.