Three naphthalenedisulfonate polymers with imidazole-containing ligands: Synthesis, structure and heterogeneously catalytic performance in reactions of enamination of β-dicarbonyl compounds

•Three new coordination polymers of Cd(II) and Cu(I) containing arenedisulfonates as ligands were synthesized.•All naphthalenedisulfonate ligands act in bridging coordination mode in all compounds.•Naphthalenedisulfonate copper complex are tested as heterogeneous catalysts for chemo- and regio-selective enamination of β-ketoesters.

Three new naphthalenedisulfonate polymers, [Cd(2,6-nds)(bib)]n (1), [Cd(1,5-nds)(bib)]n (2), and [Cu(2,6-nds)0.5(tpim)]n (3), have been successfully synthesized by hydrothermal reactions of corresponding metal salts with naphthalenedisulfonate (nds) and imidazole-containing ligands 1,4-bis(imidazol-1-ylmethyl)benzene (bib) and 2,4,5-tri(4-pyridyl)-imidazole (tpim). The structures of these polymers were determined by single crystal X-ray diffraction analysis. Polymers 1 and 2 crystallize in the same space group and have similar cell parameters, and thus show same three-dimensional (3D) framework architecture. Complex 3 has the same 2D layer structure. The photoluminescent properties of the complexes 1 and 2 were investigated. Catalytic tests indicate that complex 3 has chemo- and regio-selective catalytic activity towards enamination of β-ketoesters.

Graphical abstractThree new crystal structures of arenedisulfonate polymers formed by imidazole-containing ligands were determined by X-ray diffraction method and their photoluminescent properties and catalytic activity towards enamination of β-ketoesters were investigated.Figure optionsDownload full-size imageDownload as PowerPoint slide