A series of entangled coordination polymers assembled by a V-shaped bisimidazole ligand and various dicarboxylic acids: synthesis, characterization and luminescence properties

Abstract

Based on a V-shaped bisimidazole ligand and various dicarboxylic acids, nine entangled coordination polymers, namely, [Zn(o-bdc)(bips)]·2H₂O (1), [Zn₂(cdc)₂(bips)₂]·2H₂O (2), [Zn₂(bpedc)₂(bips)₂] (3), [Zn(odc)(bips)]·H₂O (4), [Zn₂(sdc)₂(bips)₂]·5H₂O (5), [Co₂(sdc)₂(bips)₂(H₂O)]·2H₂O (6), [Cd₂(bpdc)₂(bips)₂]·3H₂O (7), [Cd₂(2,6-ndc)₂(bips)₂(H₂O)₂]·2H₂O (8) and [Cd(1,4-ndc)(bips)]·DMF·H₂O (9) (bips = bis(4-imidazol-ylphenyl)sulfone, o-H₂bdc = o-phenyldicarboxylic acid, H₂cdc = 1,4-cyclohexanedicarboxylic acid, H₂bpedc = 4,4′-stibenedicarboxylic acid, H₂odc = 4,4′-oxybisbenzoic acid, H₂sdc = 4,4′-sulfonyldibenzoic acid, H₂bpdc = biphenyl-4,4′-dicarboxylic acid, 1,4-H₂ndc = naphthalene-1,4-dicarboxylic acid, 2,6-H₂ndc = naphthalene-1,4-dicarboxylic acid), have been synthesized and structurally characterized. Compound 1 exhibits a 2D → 2D polycatenane of 3-fold interpenetrated sql layers. Compound 2 shows a 2D → 3D polycatenane of 3-fold interpenetrated sql layers. Compound 3 displays a 2D → 3D polycatenane of 5-fold interpenetrated sql layers. Compound 4 exhibits a 2-fold interpenetration of CdSO₄ networks. Compound 5 presents a 2D → 3D polycatenane by three-fold interpenetrated {4²·6³·8}₂ layers. Compound 6 features an unusual 2D → 2D polycatenane framework assembled by the entanglement of sql layers containing 2-membered loops. Compound 7 exhibits a 1D → 3D polycatenane by the 3-fold interpenetration of 3-connected ribbons. Compound 8 displays a 3-fold interpenetration of SrAl₂ networks. Compound 9 exhibits a 4-fold interpenetration of dia networks in a [2 + 2] mode. Their luminescence properties were also measured.