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.

Magnetic and thermodynamic control of coordination network crystallization using a hexaazaphenalene-based ligand

“…Previous research demonstrated that magnetic fields of less than 1 T could completely alter the reaction pathway and generate networks with markedly different properties. 20–22 This method was also applied to the polymorph control during the crystallization of pharmaceutically active compounds. 23…”