A new route for the syntheses of coordination polymers using magnetic influence: syntheses, crystal structures and fluorescence properties

Abstract

Five coordination polymers [TM1(absa)(H2O)4]n and [TM2(absa)(bipy)(H2O)]n [TM1 = Zn (1), Co (2); TM2 = Zn (3), Co (4), Cu (5); Na2absa = 5,5′-azobissalicylic acid disodium salt; bipy = 4,4′-bipyride] were synthesized by solvent evaporation under a magnetic field. It is evident that magnetic fields bring significant and noticeable changes to the absa2− ligand orientation and the component movement behaviors to construct coordination polymers. The absa2− ligands bind to the metal ions in bridging coordination mode through the carboxylate groups, in addition to the bipy molecules adopting bridging modes. Photoluminescence measurements indicate that the emissions of compounds 1–5 are at 626, 600, 632, 658 and 682 nm in the solid state, respectively.

Keywords

• coordination polymers
• fluorescence
• synthetic approach
• transition metals
• crystallization and crystal growth